Radar device

Abstract

The invention relates to a radar device. The transmission array antenna is configured from a plurality of transmission antenna groups, each of which includes a plurality of transmission antennas arranged along a first direction at a second interval that is an integer multiple of the first interval, and is arranged at a fourth interval in a second direction orthogonal to the first direction. The reception array antenna is configured from a plurality of reception antenna groups each including a plurality of reception antennas arranged at a fifth interval that is an interval that is an integral multiple of the first interval in the first direction and arranged at a sixth interval in the second direction, the sixth interval being an interval that is an integral multiple of the third interval in the first direction, and the fourth interval being an interval that is an integral multiple of the third interval in the second direction. The sixth interval is an interval which is integral multiple of the third interval, the difference between the second interval and the fifth interval is the first interval, and the difference between the fourth interval and the sixth interval is the third interval.

Description

[0001] (This application is a divisional application of the application filed on February 14, 2020, with application number 2020800225102 and title "Radar Device".) Technical Field

[0002] This invention relates to radar devices. Background Technology

[0003] In recent years, research has been advancing on radar devices that utilize short-wavelength radar signals that can achieve high resolution, such as microwaves or millimeter waves. Furthermore, to improve safety outdoors, there is a demand for radar devices that can detect not only vehicles but also objects (targets) including pedestrians over a wider field of view (hereinafter referred to as "wide-angle radar devices").

[0004] For example, pulse radar devices that repeatedly transmit pulse waves are known as radar devices. Wide-angle pulse radar devices that detect vehicles / pedestrians over a wider angular range tend to receive signals that are a mixture of multiple reflected waves from targets located at close range (e.g., vehicles) and targets located at distant range (e.g., pedestrians). Therefore, (1) for the radar transmitter, it is required to transmit pulse waves or pulse-modulated waves with autocorrelation characteristics exhibiting low range sidelobes (hereinafter referred to as "low range sidelob characteristics"), and (2) for the radar receiver, it is required to have a structure with a wide receiving dynamic range.

[0005] The following two structures can be cited as examples of wide-angle radar devices.

[0006] The first configuration is as follows: A directional beam with a narrower angle (e.g., a beamwidth of a few degrees) than the radar device's intended detection angle is used to mechanically or electronically transmit radar waves, and the narrow-angle directional beam is used to receive reflected waves. In this configuration, a large number of scans are required to achieve high resolution, thus degrading tracking performance for high-speed moving targets.

[0007] The second structure is as follows: The reflected wave is received by an array of antennas (antenna elements), and the angle of arrival (DOA) of the reflected wave is estimated using a signal processing algorithm based on the received phase difference relative to the element spacing (antenna spacing). In this structure, even with increased scanning angle spacing of the transmitted beam, the DOA can be estimated in the receiving branch, thus shortening the scanning time and improving tracking performance compared to the first structure. Examples of DOA estimation methods include Fourier transform based on matrix operations, Capon's method and LP (Linear Prediction) based on inverse matrix operations, or MUSIC (Multiple Signal Classification) and ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques) based on intrinsic value operations.

[0008] In addition, as a radar device, a structure has been proposed that includes multiple antennas (array antennas) in the transmitting branch in addition to the receiving branch, and beam scanning is performed by signal processing of the transceiver array antennas (for example, see Non-Patent Document 1).

[0009] In MIMO radar, by carefully planning the configuration of antenna elements in the transmit and receive array antennas, a virtual receive array antenna (hereinafter referred to as "virtual receive array") can be constructed with a maximum size equal to the product of the number of transmit antenna elements and the number of receive antenna elements. This allows for an increase in the effective aperture length of the array antenna with a smaller number of elements, thereby improving angular resolution.

[0010] In addition to performing one-dimensional scanning (angle measurement) in the vertical or horizontal direction, MIMO radar can also be applied when performing two-dimensional beam scanning in both the vertical and horizontal directions (for example, see Non-Patent Document 2).

[0011] Existing technical documents

[0012] Non-patent literature

[0013] Non-patent literature 1: J. Li, P. Stoica, “MIMO Radar with Colocated Antennas,” Signal Processing Magazine, IEEE Vol. 24, Issue: 5, pp. 106-114, 2007.

[0014] Non-patent literature 2: PPVaidyanathan, P.Pal, Chun-Yang Chen, "MIMO radar with broadcast waveforms: Smearing filter banks and 2D virtual arrays,"

[0015] IEEE Asilomar Conference on Signals, Systems and Computers, pp.188-192, 2008.

[0016] Non-patent document 3: J.Wenger, "Automotive mm-wave radar: status and trends in system design and technology," IEE Colloquium on Automotive Radar andNavigation Techniques (Ref. No. 1998 / 230), pp. 144-147, 1998.

[0017] Non-patent document 4: M.Harte, T.Mahler, T.Schipper, A.Ziroff, and T.Zwick, "2-Dantenna array geometries for MIMO radar imaging by digital beamforming," 2013European Microwave Conference, pp.1695-1698, 2013. Summary of the Invention

[0018] However, the detection performance of radar devices can sometimes be degraded depending on the antenna configuration of the transceiver branches in a MIMO radar.

[0019] Non-limiting embodiments of the present invention contribute to providing radar devices capable of improving detection performance.

[0020] An embodiment of the radar device of the present invention includes: a radar transmitting circuit that transmits radar signals using a transmitting array antenna; and a radar receiving circuit that receives reflected wave signals of the radar signals after reflection from a target using a receiving array antenna. The transmitting array antenna is composed of a plurality of transmitting antenna groups, each of the plurality of transmitting antenna groups including a plurality of transmitting antennas arranged at a second interval along a first direction and arranged at a fourth interval in a second direction orthogonal to the first direction, wherein the second interval is an integer multiple of the first interval and the fourth interval is an integer multiple of the third interval. The receiving array antenna is composed of a plurality of receiving antenna groups, each of the plurality of receiving antenna groups including a plurality of receiving antennas arranged at a fifth interval along the first direction and arranged at a sixth interval in the second direction, wherein the fifth interval is an integer multiple of the first interval and the sixth interval is an integer multiple of the third interval, the difference between the second interval and the fifth interval is the first interval, and the difference between the fourth interval and the sixth interval is the third interval.

[0021] Furthermore, these general or specific embodiments can be implemented by systems, apparatuses, methods, integrated circuits, computer programs, or recording media, or by any combination of systems, apparatuses, methods, integrated circuits, computer programs, and recording media.

[0022] According to one embodiment of the present invention, the detection performance of a radar device can be improved.

[0023] Further advantages and effects of one embodiment of the present invention can be further understood from the description and accompanying drawings. The above advantages and / or effects are provided through several embodiments and the features disclosed in the description and accompanying drawings, without necessarily providing all features to obtain one or more identical features. Attached Figure Description

[0024] Figure 1A This is a diagram showing an example of the configuration of the transmitting and receiving antennas.

[0025] Figure 1B This is a diagram illustrating a configuration example of a virtual receiver array.

[0026] Figure 2A This indicates that it is controlled by a virtual receiver array (d) V The diagram of the directional pattern generated by (=0.5λ).

[0027] Figure 2B This indicates that it is controlled by a virtual receiver array (d) V The diagram of the directional pattern generated by (=0.5λ).

[0028] Figure 3A This indicates that it is controlled by a virtual receiver array (d) V=λ) is a diagram of the directional pattern generated by the directional pattern.

[0029] Figure 3B This indicates that it is controlled by a virtual receiver array (d) V =2λ) is a diagram of the directional pattern generated.

[0030] Figure 4 It is a block diagram representing the structure of a radar device.

[0031] Figure 5 This is a diagram illustrating an example of a radar transmitting a signal.

[0032] Figure 6 This is a block diagram representing other structures of the radar signal generation unit.

[0033] Figure 7 This is a diagram illustrating the timing of radar signal transmission and the measurement range.

[0034] Figure 8 This is a diagram illustrating an example of antenna configuration 1 in basic configuration.

[0035] Figure 9A This is a diagram illustrating an example of a subarray structure.

[0036] Figure 9B This is a diagram illustrating an example of a subarray structure.

[0037] Figure 9C This is a diagram illustrating an example of a subarray structure.

[0038] Figure 10 This is a diagram illustrating a structural example of a transmit array antenna that uses a subarray.

[0039] Figure 11A This is a diagram showing an example of the directional estimation results using the transmit and receive antenna configuration of basic configuration 1.

[0040] Figure 11B It means that it was used Figure 1A A figure showing an example of the directional estimation results for the transmit and receive antenna configuration.

[0041] Figure 12 This is a diagram showing an example of an antenna configuration of variation 1 of the basic configuration 1.

[0042] Figure 13 This is a diagram showing an example of an antenna configuration of variation 1 of the basic configuration 1.

[0043] Figure 14 This is a diagram showing an example of an antenna configuration of variation 1 of the basic configuration 1.

[0044] Figure 15 This is a diagram showing an example of an antenna configuration of variation 1 of the basic configuration 1.

[0045] Figure 16 This is a diagram showing an example of an antenna configuration, variant 2 of basic configuration 1.

[0046] Figure 17 This is a diagram showing an example of an antenna configuration, variant 2 of basic configuration 1.

[0047] Figure 18 This is a diagram showing an example of an antenna configuration, variant 2 of basic configuration 1.

[0048] Figure 19 This is a diagram showing an example of an antenna configuration, variant 2 of basic configuration 1.

[0049] Figure 20 This is a diagram showing an example of an antenna configuration, variant 2 of basic configuration 1.

[0050] Figure 21 This is a diagram showing an example of antenna configuration for variation 3 of basic configuration 1.

[0051] Figure 22 This is a diagram showing an example of antenna configuration for variation 3 of basic configuration 1.

[0052] Figure 23 This is a diagram showing an example of antenna configuration for variation 3 of basic configuration 1.

[0053] Figure 24 This is a diagram showing an example of antenna configuration for variation 3 of basic configuration 1.

[0054] Figure 25A This is a diagram illustrating the structure of a subarray of variant 3 of basic configuration 1.

[0055] Figure 25B This is a diagram illustrating the structure of a transmit array antenna using a subarray of variant 3 of basic configuration 1.

[0056] Figure 25C This is a diagram illustrating the structure of a transmit array antenna using a subarray of variant 3 of basic configuration 1.

[0057] Figure 26 This is a diagram showing an antenna configuration example that combines the basic configuration 1 in variant 3 and variant 1.

[0058] Figure 27 This is a diagram showing an antenna configuration example that combines the basic configuration 1 in variant 3 and variant 1.

[0059] Figure 28 This is a diagram showing an antenna configuration example that combines the basic configuration 1 in variant 3 and variant 1.

[0060] Figure 29This is a diagram showing an antenna configuration example that combines the basic configuration 1 in variant 3 and variant 1.

[0061] Figure 30 This is a diagram showing an antenna configuration example that combines the basic configuration 1 in variant 3 and variant 1.

[0062] Figure 31 This is a diagram showing an antenna configuration example that combines the basic configuration 1, variant 3, and variant 2.

[0063] Figure 32 This is a diagram showing an antenna configuration example that combines the basic configuration 1, variant 3, and variant 2.

[0064] Figure 33 This is a diagram showing an antenna configuration example that combines the basic configuration 1, variant 3, and variant 2.

[0065] Figure 34 This is a diagram showing an example of the antenna configuration for basic configuration 2.

[0066] Figure 35 This is a diagram illustrating an example of the structure of a subarray in basic configuration 2.

[0067] Figure 36 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 2.

[0068] Figure 37 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 2.

[0069] Figure 38 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 2.

[0070] Figure 39 This is a diagram showing an example of an antenna configuration, which is a variation of the basic configuration 2.

[0071] Figure 40 This is a diagram showing an example of an antenna configuration, which is a variation of the basic configuration 2.

[0072] Figure 41 This is a diagram showing an example of an antenna configuration, which is a variation of the basic configuration 2.

[0073] Figure 42 This is a diagram showing an example of an antenna configuration, which is a variation of the basic configuration 2.

[0074] Figure 43 This is a diagram showing an example of an antenna configuration, which is a variation of the basic configuration 2.

[0075] Figure 44 This is a diagram showing an example of an antenna configuration, variant 3, of basic configuration 2.

[0076] Figure 45 This is a diagram showing an example of an antenna configuration, variant 3, of basic configuration 2.

[0077] Figure 46 This is a diagram showing an example of an antenna configuration, variant 3, of basic configuration 2.

[0078] Figure 47 This is a diagram showing an example of an antenna configuration, variant 3, of basic configuration 2.

[0079] Figure 48 This is a diagram showing a modified example 3 that combines the basic configuration 2 with an antenna configuration example of modified example 2.

[0080] Figure 49 This is a diagram showing a modified example 3 that combines the basic configuration 2 with an antenna configuration example of modified example 2.

[0081] Figure 50A This is a diagram showing a modified example 3 that combines the basic configuration 2 with an antenna configuration example of modified example 2.

[0082] Figure 50B This is a diagram showing a modified example 3 that combines the basic configuration 2 with an antenna configuration example of modified example 2.

[0083] Figure 51A This is a diagram showing a modified example 3 that combines the basic configuration 2 with an antenna configuration example of modified example 2.

[0084] Figure 51B This is a diagram showing a modified example 3 that combines the basic configuration 2 with an antenna configuration example of modified example 2.

[0085] Figure 52A This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0086] Figure 52B This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0087] Figure 52C This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0088] Figure 52D This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0089] Figure 53A This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0090] Figure 53B This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0091] Figure 53C This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0092] Figure 53DThis is a diagram showing an example of the antenna configuration for basic configuration 3.

[0093] Figure 54A This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0094] Figure 54B This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0095] Figure 54C This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0096] Figure 54D This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0097] Figure 55A This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0098] Figure 55B This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0099] Figure 55C This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0100] Figure 55D This is a diagram showing an example of the antenna configuration for basic configuration 3.

[0101] Figure 56A This is a diagram illustrating a structural example of a transmit array antenna using a subarray with basic configuration 3.

[0102] Figure 56B This is a diagram illustrating a structural example of a transmit array antenna using a subarray with basic configuration 3.

[0103] Figure 57 This is a diagram showing an example of the directional estimation results using the transmit and receive antenna configuration of basic configuration 3.

[0104] Figure 58 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 3.

[0105] Figure 59 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 3.

[0106] Figure 60 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 3.

[0107] Figure 61 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 3.

[0108] Figure 62 This is a diagram showing an example of the directional estimation results for the transmit and receive antenna configuration of variant 1 using basic configuration 3.

[0109] Figure 63 This is a diagram showing an example of the antenna configuration of variation 2 of basic configuration 3.

[0110] Figure 64 This is a diagram showing an example of the antenna configuration of variation 2 of basic configuration 3.

[0111] Figure 65 This is a diagram showing an example of the antenna configuration of variation 2 of basic configuration 3.

[0112] Figure 66 This is a diagram showing an example of the antenna configuration of variation 2 of basic configuration 3.

[0113] Figure 67 This is a diagram showing an example of the antenna configuration of variation 2 of basic configuration 3.

[0114] Figure 68A This is a diagram showing an example of the antenna configuration of variation 2 of basic configuration 3.

[0115] Figure 68B This is a diagram showing an example of the antenna configuration of variation 2 of basic configuration 3.

[0116] Figure 69 This is a diagram showing an example of the antenna configuration for basic configuration 4.

[0117] Figure 70A This is a diagram illustrating a structural example of a transmit array antenna using a subarray with basic configuration 4.

[0118] Figure 70B This is a diagram illustrating a structural example of a transmit array antenna using a subarray with basic configuration 4.

[0119] Figure 71 This is a diagram showing an example of the directional estimation results using the transmit and receive antenna configuration of basic configuration 4.

[0120] Figure 72 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 4.

[0121] Figure 73 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 4.

[0122] Figure 74 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 4.

[0123] Figure 75 This is a diagram showing an example of the directional estimation results for the transmit and receive antenna configuration of variant 1 using basic configuration 4.

[0124] Figure 76 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 4.

[0125] Figure 77 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 4.

[0126] Figure 78 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 4.

[0127] Figure 79 This is an example of the directional estimation result of the transmit and receive antenna configuration of variant 1 using basic configuration 4.

[0128] Figure 80 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 4.

[0129] Figure 81 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 4.

[0130] Figure 82 This is a diagram showing an example of the antenna configuration of variation 1 of basic configuration 4.

[0131] Figure 83 This is a diagram showing an example of the antenna configuration of variation 2 of the basic configuration 4.

[0132] Figure 84 This is a diagram showing an example of the antenna configuration of variation 2 of the basic configuration 4.

[0133] Figure 85 This is a diagram showing an example of the antenna configuration of variation 2 of the basic configuration 4.

[0134] Figure 86 This is a diagram showing an example of the antenna configuration of variation 2 of the basic configuration 4.

[0135] Figure 87 This is a diagram showing an example of the antenna configuration of variation 2 of the basic configuration 4.

[0136] Figure 88A This is a diagram showing an example of the antenna configuration of variation 2 of the basic configuration 4.

[0137] Figure 88B This is a diagram showing an example of the antenna configuration of variation 2 of the basic configuration 4.

[0138] Figure 89 This is a diagram illustrating an example of antenna configuration for basic configuration 5.

[0139] Figure 90A This is a diagram illustrating an example of antenna configuration for basic configuration 5.

[0140] Figure 90B This is a diagram illustrating an example of antenna configuration for basic configuration 5.

[0141] Figure 91A This is a diagram illustrating an example of antenna configuration for basic configuration 5.

[0142] Figure 91B This is a diagram illustrating an example of antenna configuration for basic configuration 5.

[0143] Figure 92A This is a diagram illustrating an example of antenna configuration for basic configuration 5.

[0144] Figure 92B This is a diagram illustrating an example of antenna configuration for basic configuration 5.

[0145] Figure 92C This is a diagram illustrating an example of antenna configuration for basic configuration 5.

[0146] Figure 92D This is a diagram illustrating an example of antenna configuration for basic configuration 5.

[0147] Figure 93A This is a diagram illustrating a structural example of a transmit array antenna using a subarray with basic configuration 5.

[0148] Figure 93B This is a diagram illustrating a structural example of a transmit array antenna using a subarray with basic configuration 5.

[0149] Figure 94 This is a diagram showing an example of the directional estimation results using the transmit and receive antenna configuration of basic configuration 5.

[0150] Figure 95 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0151] Figure 96 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0152] Figure 97 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0153] Figure 98 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0154] Figure 99 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0155] Figure 100A This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0156] Figure 100B This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0157] Figure 101This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0158] Figure 102 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0159] Figure 103 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0160] Figure 104 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0161] Figure 105 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0162] Figure 106A This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0163] Figure 106B This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0164] Figure 107 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0165] Figure 108 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0166] Figure 109 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0167] Figure 110 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0168] Figure 111 This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0169] Figure 112A This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0170] Figure 112B This is a diagram showing an example of the antenna configuration of variation 1 of the basic configuration 5.

[0171] Explanation of reference numerals in the attached figures

[0172] 10. Radar Equipment

[0173] 100 Radar Transmission Unit

[0174] 200 Radar Receiving Unit

[0175] 300 Reference Signal Generation Unit

[0176] 101 and 101a radar signal generation units

[0177] 102 Coding Generation Department

[0178] 103 Modulation Section

[0179] 104LPF (Low Pass Filter)

[0180] 105 Wireless Transmission Unit

[0181] 106 transmitting antennas

[0182] 111 Encoding and Storage Department

[0183] 112DA (digital-to-analog) conversion unit

[0184] 201 Antenna System Processing Department

[0185] 202 Receiving Antenna

[0186] 203 Wireless Receiver Unit

[0187] 204 Amplifier

[0188] 205 Frequency Converter

[0189] 206 Quadrature Detector

[0190] 207 Signal Processing Department

[0191] 208, 209 AD (analog-to-digital) conversion section

[0192] 210 Separation Section

[0193] 211 Related Computing Department

[0194] 212 Addition Department

[0195] 213 Doppler Frequency Analysis Section

[0196] 214 Direction Estimation Department Detailed Implementation

[0197] As mentioned above, in addition to performing one-dimensional scanning (angle measurement) in the vertical or horizontal direction, MIMO radar constituting a virtual receiving array can also be applied when performing two-dimensional beam scanning in both the vertical and horizontal directions.

[0198] As an example, Figure 1A This indicates that it includes the vertical direction ( Figure 1AThe transmitting array antenna consists of four transmitting antennas (Tx#1 to Tx#4) arranged in the vertical direction, and includes transmitting array antennas arranged in the horizontal direction. Figure 1A The receiving array antenna consists of four receiving antennas (Rx#1 to Rx#4) configured horizontally. Figure 1A In the middle, the transmitting antennas are evenly spaced along the vertical direction (d V The receiving antennas are configured such that they are evenly spaced (d) along the horizontal direction. H (e.g., see non-patent literature 4).

[0199] Figure 1B Indicates inclusion Figure 1A The antenna configuration shown is a virtual receiver array of the transceiver array antenna. Figure 1B The virtual receiving array shown consists of 16 virtual receiving antenna elements (VA#1 to VA#16), arranged in a rectangular shape with four antennas horizontally and four antennas vertically. Figure 1B In the virtual receiver array, the horizontal and vertical element spacings are d and d, respectively. H d V That is, the aperture length D in the horizontal and vertical directions of the virtual receiving array. H D V 3D respectively H 3D V .

[0200] Figure 2A and Figure 2B Indicates in Figure 1A and Figure 1B In the antenna configuration of the MIMO radar shown, the horizontal element spacing d H =0.5λ, vertical component spacing d V Fourier beam patterns in the horizontal and vertical directions when the wavelength is 0.5λ. Furthermore, λ represents the wavelength of the radar carrier wave.

[0201] like Figure 2A and Figure 2B As shown, the main beam (main lobe) is formed in the horizontal and vertical directions of 0°. Here, the narrower the beamwidth of the main beam, the higher the angular separation performance for multiple targets. For example, in... Figure 2A and Figure 2B In this case, the beamwidth at a power of 3dB is approximately 13°. Additionally, as... Figure 2A and Figure 2BAs shown, side lobes are generated around the main beam. In radar systems, side lobes are a major cause of false artifact detection. Therefore, the lower the peak level of the side lobes, the lower the probability of the radar system falsely detecting them as artifacts. Figure 2A and Figure 2B In this context, the power ratio relative to the peak level of the sidelobes (Peak Sidelobe Level Ratio (PSLR)) obtained by normalizing based on the peak level of the main beam is approximately -13 dB.

[0202] To extend the detection range in radar devices, it is effective to use high-gain antennas. For example, antenna gain can be increased by narrowing the antenna's directivity (beamwidth). For instance, the larger the antenna aperture, the narrower the antenna's directivity. Consequently, to narrow the antenna's directivity, the antenna size must be increased.

[0203] For example, in radar devices mounted on vehicles (e.g., also called "vehicle-mounted radar"), a subarray antenna consisting of multiple antenna elements arranged along the vertical direction is used to narrow the directivity in the vertical direction (e.g., see Non-Patent Document 3). By narrowing the directivity in the vertical direction, the antenna gain in the vertical direction can be improved, thereby reducing reflected waves from unwanted directions such as the road surface.

[0204] However, when subarray antennas are used as antenna elements constituting transmit or receive array antennas, it is difficult to configure the element spacing of the array antenna to be narrower than the size of the subarray antennas. For example, when the antenna elements constituting the subarray antennas are arranged along the vertical direction, the size of the subarray antenna can reach more than one wavelength. Therefore, for example, in... Figure 1A In the MIMO radar shown, when using subarray antennas along the vertical direction, the vertical element spacing d needs to be adjusted. V Expand to a wavelength or more.

[0205] Figure 3A and Figure 3B Indicates in Figure 1A In the MIMO radar transmit / receive antenna configuration shown, the vertical element spacing is d. V An example of Fourier beamforms oriented towards 0° horizontally and 0° vertically, assuming a wavelength (λ) or greater. Furthermore, in... Figure 3A and Figure 3B In this study, the individual directivity of antenna elements forming subarrays along the vertical direction is not considered.

[0206] In addition, Figure 3A In the middle, the vertical element spacing d V =λ, horizontal component spacing d H=0.5λ, in Figure 3B In the middle, the vertical element spacing d V =2λ, horizontal component spacing d H =0.5λ.

[0207] like Figure 3A and Figure 3B As shown, the main beam (main lobe) is oriented towards the horizontal and vertical directions of 0°, for example, with... Figure 2A and Figure 2B Compared to the sidelobes, high-level grating lobes are generated in the vertical direction towards the periphery of the main beam. Figure 3A and Figure 3B In this model, the ratio of the peak level of the grating lobe to the peak level of the main lobe is 0 dB. Additionally, compared to... Figure 3A (d V Compared to λ), Figure 3B (d V In (2λ), the angular spacing of the gate lobes that generate a high level in the vertical direction becomes narrower. That is, the following property can be confirmed: the element spacing d in the vertical direction... V The wider the grid, the narrower the angular spacing produced by the grating lobes.

[0208] Thus, the larger the vertical antenna size of the radar device, the wider the vertical element spacing, making it easier to generate grating lobes at angles closer to the main beam. Therefore, if the detection angle range designed for the radar device is greater than the angle at which grating lobes are generated, the probability of the radar device mistakenly detecting false peaks caused by grating lobes as targets (objects) within the detection angle range increases, and the detection performance of the radar device deteriorates.

[0209] In one embodiment of the present invention, when using MIMO radar to perform two-dimensional beam scanning in the vertical and horizontal directions, even if the antenna size (or component size) in the vertical or horizontal direction reaches more than one wavelength, the generation of grating lobes will be suppressed, thereby improving the angular resolution in the vertical or horizontal direction.

[0210] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in the embodiment, the same constituent elements are labeled with the same reference numerals, and their descriptions are omitted due to repetition.

[0211] Furthermore, the following describes the structure of a radar device where, in the transmit branch, different transmitted signals multiplexed by code division are sent from multiple transmit antennas, and in the receive branch, each transmitted signal is separated and processed for reception. However, the structure of the radar device is not limited to this; it can also be structured such that, in the transmit branch, different transmitted signals multiplexed by frequency division are sent from multiple transmit antennas, and in the receive branch, each transmitted signal is separated and processed for reception. Similarly, the radar device can also be structured such that, in the transmit branch, transmitted signals multiplexed by time division are sent from multiple transmit antennas, and in the receive branch, processing for reception is performed.

[0212] [Implementation Method 1]

[0213] [Structure of a radar device]

[0214] Figure 4 This is a block diagram showing the structure of the radar device 10 according to this embodiment.

[0215] The radar device 10 includes a radar transmitting unit (transmitting branch) 100, a radar receiving unit (receiving branch) 200, and a reference signal generating unit 300.

[0216] The radar transmitter 100 generates a high-frequency radar signal (radar transmission signal) based on a reference signal received from the reference signal generation unit 300. Then, the radar transmitter 100 transmits the radar transmission signal at a predetermined transmission period using a transmission array antenna composed of multiple transmission antennas 106-1 to 106-Nt.

[0217] The radar receiver 200 uses a receiving array antenna comprising multiple receiving antennas 202-1 to 202-Na to receive the reflected wave signal after the radar-transmitted signal is reflected by a target (not shown). The radar receiver 200 uses a reference signal received from the reference signal generation unit 300 to perform processing operations synchronized with the radar transmitter 100. Specifically, the radar receiver 200 performs signal processing on the reflected wave signal received in each receiving antenna 202, and performs at least one of the following processes: target detection processing and direction estimation processing. Furthermore, the target is an object detected by the radar device 10, such as a vehicle (including four-wheeled and two-wheeled vehicles) or a person.

[0218] The reference signal generation unit 300 is connected to the radar transmitter 100 and the radar receiver 200, respectively. The reference signal generation unit 300 provides a reference signal, which serves as a reference signal, to the radar transmitter 100 and the radar receiver 200, thereby synchronizing the processing of the radar transmitter 100 and the radar receiver 200.

[0219] [Structure of Radar Transmitter 100]

[0220] The radar transmitter 100 includes radar signal generation units 101-1 to 101-Nt, wireless transmitter units 105-1 to 105-Nt, and transmitting antennas 106-1 to 106-Nt. That is, the radar transmitter 100 has Nt transmitting antennas 106, and each transmitting antenna 106 is connected to a separate radar signal generation unit 101 and a wireless transmitter unit 105.

[0221] The radar transmission signal generation unit 101 generates a timing clock obtained by setting the reference signal received from the reference signal generation unit 300 to a predetermined multiple, and generates a radar transmission signal based on the generated timing clock. Then, the radar transmission signal generation unit 101 repeatedly outputs the radar transmission signal at a predetermined radar transmission period (Tr). The radar transmission signal is generated by r... z (k, M) = I z (k, M) + j Q z (k, M) represents the number corresponding to each transmitting antenna 106, z = 1, ..., Nt. Additionally, j represents the imaginary unit, k represents the discrete time, and M represents the ordinal number of the radar transmission period.

[0222] Each radar transmit signal generation unit 101 includes an encoding generation unit 102, a modulation unit 103, and an LPF (Low Pass Filter) 104. Hereinafter, each component of the radar transmit signal generation unit 101-z corresponding to the z-th (z = 1, ..., Nt) transmit antenna 106 will be described.

[0223] For example, the encoding generation unit 102 generates the encoding a(z) of the encoding sequence with code length L according to the radar transmission period Tr. n (n = 1, ..., L) (Pulse coding). Codes that are lowly correlated or uncorrelated with each other are used as the codes a(z) generated in each code generation unit 102-1 to code generation unit 102-Nt. n (z = 1, ..., Nt). Examples of coding sequences include Walsh-Hadamard coding, M-sequence coding, and Gold coding.

[0224] The modulation unit 103 encodes the coded sequence (e.g., a(z)) output from the encoding generation unit 102. n It performs pulse modulation (amplitude modulation, ASK (Amplitude Shift Keying), pulse offset keying) or phase modulation (phase shift keying) and outputs the modulated signal to LPF104.

[0225] LPF104 outputs the signal components below a specified frequency band from the modulation signal output from modulation unit 103 as baseband radar transmission signals to radio transmission unit 105.

[0226] The z-th (z = 1, ..., Nt) wireless transmitter 105 performs frequency conversion on the baseband radar transmission signal output from the z-th radar transmission signal generation unit 101 to generate a carrier frequency (RF) radar transmission signal, and amplifies it to a predetermined transmission power P [dB] by a transmission amplifier before outputting it to the z-th transmission antenna 106.

[0227] The z-th (z = 1, ..., Nt) transmitting antenna 106 radiates the radar transmission signal output from the z-th wireless transmitter 105 into space.

[0228] Figure 5 This represents the radar transmitted signals from the Nt transmitting antennas 106 of the radar transmitting unit 100. The coded transmission interval Tw contains a pulse-coded sequence of code length L. During the coded transmission interval Tw in each radar transmission period Tr, the pulse-coded sequence is transmitted; the remaining interval (Tr-Tw) is a no-signal interval. This is achieved by implementing each pulse code (a(z)). n The modulation unit 103 uses pulse modulation with No samples to produce a signal containing Nr (=No×L) samples in each coded transmission interval Tw. That is, the sampling rate in the modulation unit 103 is (No×L) / Tw. In addition, the no-signal interval (Tr-Tw) contains Nu samples.

[0229] In addition, the radar transmitter 100 may also include Figure 6 The radar signal generation unit 101a shown is used instead of the radar signal generation unit 101. The radar signal generation unit 101a may also be omitted. Figure 4 The encoding generation unit 102, modulation unit 103, and LPF 104 shown are replaced by an encoding storage unit 111 and a DA (Digital Analog) converter 112. The encoding storage unit 111 stores data pre-stored in the encoding generation unit 102 (…). Figure 4 The DA converter 112 converts the coded sequence (digital signal) output from the encoding storage unit 111 into an analog signal (baseband signal).

[0230] [Structure of Radar Receiver 200]

[0231] exist Figure 4In this configuration, the radar receiver 200 includes Na receiving antennas 202, thereby forming an array antenna. Additionally, the radar receiver 200 includes Na antenna system processing units 201-1 to 201-Na and a direction estimation unit 214.

[0232] Each receiving antenna 202 receives the radar transmitted signal, i.e. the reflected wave signal, after being reflected by the target (object), and outputs the received reflected wave signal as the received signal to the corresponding antenna system processing unit 201.

[0233] Each antenna system processing unit 201 includes a wireless receiving unit 203 and a signal processing unit 207.

[0234] The wireless receiver 203 includes an amplifier 204, a frequency converter 205, and a quadrature detector 206. The wireless receiver 203 generates a timing clock that is a predetermined multiple of the reference signal output from the reference signal generation unit 300, and operates based on the generated timing clock. Specifically, the amplifier 204 amplifies the received signal output from the receiving antenna 202 to a predetermined level, the frequency converter 205 performs frequency conversion to convert the high-frequency band received signal to the baseband band, and the quadrature detector 206 converts the baseband band received signal into a baseband band received signal that includes I and Q signals.

[0235] The signal processing unit 207 includes AD (Analog-to-digital) conversion units 208 and 209 and separation units 210-1 to 210-Nt.

[0236] The I signal is input to the A / D converter 208 from the quadrature detector 206, and the Q signal is input to the A / D converter 209 from the quadrature detector 206. The A / D converter 208 samples the baseband signal containing the I signal at discrete times, thereby converting the I signal into digital data. The A / D converter 209 samples the baseband signal containing the Q signal at discrete times, thereby converting the Q signal into digital data.

[0237] Here, in the sampling of the AD conversion units 208 and 209, Ns discrete samples are performed according to the time Tp (=Tw / L) of each sub-pulse in the radar transmitted signal. That is, the oversampling number of each sub-pulse is Ns.

[0238] In the following explanation, using the I signal Ir(k, M) and the Q signal Qr(k, M), the baseband received signal at discrete time k in the Mth radar transmission cycle Tr[M], which is the output of the AD conversion units 208 and 209, is represented as a complex signal x(k, M) = Ir(k, M) + j Qr(k, M). Furthermore, from now on, the discrete time k is based on the start timing of the radar transmission cycle (Tr) (k = 1), and the signal processing unit 207 operates periodically until the sampling point before the end of the radar transmission cycle Tr, i.e., k = (Nr + Nu)Ns / No. That is, k = 1, ..., (Nr + Nu)Ns / No. Here, j is the imaginary unit.

[0239] The signal processing unit 207 includes Nt separation units 210, which are equal to the number of systems corresponding to the number of transmitting antennas 106. Each separation unit 210 includes a correlation operation unit 211, an adder unit 212, and a Doppler frequency analysis unit 213. Hereinafter, the structure of the z-th (z = 1, ..., Nt) separation unit 210 will be described.

[0240] The related calculation unit 211 performs pulse coding a(z) of discrete sampled value x(k,M) including discrete sampled values ​​Ir(k,M) and Qr(k,M) received from AD conversion units 208 and 209 and code length L transmitted by radar transmission unit 100, according to the radar transmission period Tr. n (Where z = 1, ..., Nt, n = 1, ..., L) Correlation operations are performed between the discrete sampled values ​​x(k, M) and the pulse code a(z). n The sliding correlation operation between them. For example, the correlation value AC of the sliding correlation operation at discrete time k in the Mth radar transmission period Tr[M]. (z) (k, M) is calculated based on the following formula.

[0241]

[0242] In the above formula, the asterisk (*) represents the complex conjugate operator.

[0243] The related operation unit 211 performs related operations, for example, according to equation (1), during the period of k = 1, ..., (Nr + Nu)Ns / No.

[0244] Furthermore, the correlation calculation unit 211 is not limited to performing correlation operations on k = 1, ..., (Nr + Nu)Ns / No; it can also limit the measurement range (i.e., the range of k) based on the presence range of the target that is the object of measurement for the radar device 10. This reduces the computational workload of the correlation calculation unit 211. For example, the correlation calculation unit 211 can also limit the measurement range to k = Ns(L + 1), ..., (Nr + Nu)Ns / No - NsL. In this case, as... Figure 7 As shown, radar device 10 will not perform measurements within the time interval corresponding to the coded transmission interval Tw.

[0245] Therefore, even if the radar transmitted signal directly loops back to the radar receiver 200, since no processing by the correlation calculation unit 211 is performed during the loopback period (at least less than τ1), the radar device 10 can perform measurements that exclude the effects of the loopback. Furthermore, when the measurement range (range k) is limited, the processing of the addition unit 212, the Doppler frequency analysis unit 213, and the direction estimation unit 214, as described below, can also be performed using the same limited measurement range (range k) processing. This reduces the processing load of each component, thereby lowering the power consumption in the radar receiver 200.

[0246] Addition unit 212 uses the correlation operation value AC output from correlation operation unit 211 at discrete time k according to the Mth radar transmission period Tr. (z) (k, M), within a specified number (Np times) of radar transmission cycles Tr (Tr×Np), the relevant calculated value AC is... (z) (k, M) addition (coherent integration). The addition (coherent integration) of the sums Np within the period (Tr×Np) is represented by the following formula.

[0247]

[0248] Here, CI (z) (k, m) represents the addition value of the related operation (hereinafter referred to as the "related addition value"), Np is an integer value greater than or equal to 1, and m is an integer greater than or equal to 1 representing the ordinal number of the addition number when the addition number Np in the addition section 212 is taken as a unit. In addition, z = 1, ..., Nt.

[0249] The adder 212 takes the output of the correlation calculation unit 211, obtained in units of radar transmission period Tr, as a unit and performs Np additions. That is, the adder 212 adds the correlation calculation value AC... (z) (k, Np(m-1)+1)~AC (z)Using (k, Np×m) as a unit, the correlation value CI is calculated by summing the discrete time k to ensure consistent timing. (z) (k, m). Therefore, the adder 212 can utilize the effect of adding the correlated operation values ​​Np times to improve the SNR (Signal to Noise Ratio) of the reflected wave signal within a range where the reflected wave signal from the target has high correlation. Consequently, the radar receiver 200 can improve its measurement performance in estimating the target's arrival distance.

[0250] Furthermore, to obtain the ideal additive gain, it is necessary that the phase components of the correlated values ​​are consistent within a certain range during the addition interval of the number of additions Np. That is, it is preferable to set the number of additions Np based on the assumed maximum moving speed of the target being measured. The reason is that the greater the assumed maximum speed of the target, the greater the variation in the Doppler frequency contained in the reflected wave from the target. Therefore, the time period with high correlation is shortened, so the number of additions Np becomes a small value, and the gain improvement effect brought by the addition of the addition unit 212 becomes smaller.

[0251] The Doppler frequency analysis unit 213 will calculate the Nc outputs, i.e., CI, of the adder unit 212 obtained at discrete time k. (z) (k, Nc(w-1)+1)~CI (z) Using (k, Nc×w) as a unit, coherent integration is performed to ensure the timing of discrete time k is consistent. For example, the Doppler frequency analysis unit 213, as shown in the following equation, corrects the phase variation Φ(fs)=2πfs(Tr×Np)ΔΦ corresponding to 2Nf different Doppler frequencies fsΔΦ before performing coherent integration.

[0252]

[0253] Here, FT_CI (z) Nant (k, fs, w) is the w-th output of the Doppler frequency analysis unit 213, and represents the coherent integration result of the Nant-th antenna system processing unit 201 at discrete time k, where Nant = 1 to Na, fs = -Nf+1, ..., 0, ..., Nf, k = 1, ..., (Nr+Nu)Ns / No, w is an integer greater than or equal to 1, and ΔΦ is the phase rotation unit.

[0254] Therefore, each antenna system processing unit 201 obtains the coherent integral result corresponding to the 2Nf Doppler frequency components at each discrete time k, i.e., FT_CI, according to the multiple Np×Nc periods (Tr×Np×Nc) of the radar transmission cycle Tr. (z) Nant(k, -Nf+1, w), ..., FT_CI (z) Nant (k, Nf-1, w). In addition, j is the imaginary unit, z=1、…、Nt.

[0255] In the case of ΔΦ=1 / (Nc×Tr×Np), the processing of the Doppler frequency analysis unit 213 is equivalent to performing Discrete Fourier Transform (DFT) processing on the output of the adder unit 212 with a sampling interval Tm=(Tr×Np) and a sampling frequency fm=1 / Tm.

[0256] Furthermore, by setting Nf to a power of 2, the Doppler frequency analysis unit 213 can apply Fast Fourier Transform (FFT) processing, thereby reducing the computational workload. Additionally, when Nf > Nc, zero-filling processing is performed in the region q > Nc to make CI(z)(k, Nc(w-1)+q) = 0, thus allowing FFT processing to be applied again, further reducing the computational workload.

[0257] Furthermore, in the Doppler frequency analysis unit 213, the multiplication and accumulation operation shown in equation (3) above can be performed sequentially instead of the FFT process. That is, the Doppler frequency analysis unit 213 can also process the Nc outputs, i.e., CI, of the addition unit 212 obtained at discrete time k. (z) (k, Nc(w-1)+q+1), generate coefficients corresponding to fs=-Nf+1、…、0、…、Nf-1. Then, multiplication and accumulation operations are performed sequentially. Here, q = 0 to Nc⁻¹.

[0258] Furthermore, in the following description, the w-th output FT_CI obtained by performing the same processing in each of the Na antenna system processing units 201 in the following manner is described below. (z) 1 (k, fs, w), FT_CI (z) 2 (k, fs, w), ..., FT_CI (z) Na (k, fs, w) is represented by the virtual receiver array correlation vector h(k, fs, w). The virtual receiver array correlation vector h(k, fs, w) contains the product of the number of transmitting antennas Nt and the number of receiving antennas Na, i.e., Nt × Na elements. The virtual receiver array correlation vector h(k, fs, w) is used to explain the subsequent processing of the direction estimation of the reflected wave signal from the target based on the phase difference between the receiving antennas 202. Here, z = 1, ..., Nt, b = 1, ..., Na.

[0259]

[0260] The above describes the processing in each component of the signal processing unit 207.

[0261] For the virtual receiver array correlation vector h(k, fs, w) output from the antenna system processing units 201-1 to 201-Na, the direction estimation unit 214 calculates the array correction value h_cal using the array correction value h_cal. [y] The virtual receiver array correlation vector h corrects the phase and amplitude deviations between the antenna system processing units 201. _after_cal (k, fs, w). Virtual receiver array correlation vector h _after_cal (k, fs, w) is represented by the following formula. Furthermore, y = 1, ..., (Nt × Na).

[0262]

[0263] The virtual receiver array correlation vector h, corrected for inter-antenna misalignment. _after_cal (k, fs, w) is a column vector containing Na × Nr elements. The following will discuss the virtual receiver array related vector h. _after_cal The elements of (k, fs, w) are represented as h1(k, fs, w), ..., h Na×Nr (k, fs, w) is a description of the direction estimation process.

[0264] [Antenna configuration in radar unit 10]

[0265] The configuration of the Nt transmitting antennas 106 and Na receiving antennas 202 in the radar device 10 having the above structure will be described.

[0266] <Basic Configuration 1>

[0267] Figure 8 Examples of configurations for the transmitting antenna 106 and receiving antenna 202 in basic configuration 1, and examples of configurations for the virtual receiving array.

[0268] Furthermore, in the following description, for example, the horizontal direction is used (e.g., Figure 8 The horizontal spacing D in the middle H and the vertical direction (e.g., Figure 8 The interval D in the vertical direction V Same. However, interval D H With interval D V They can also be different.

[0269] (1) Configuration of transceiver antennas

[0270] exist Figure 8 In the transmitting array antenna, the number of transmitting antennas 106 is Nt = 4 (Tx#1, Tx#2, Tx#3 and Tx#4), and the number of receiving antennas 202 is Na = 4 (Rx#1, Rx#2, Rx#3 and Rx#4).

[0271] Figure 8 The transmitted array antenna shown consists of the "first transmitted antenna group" ( Figure 8 Tx#2, Tx#4) and "second transmitting antenna group" ( Figure 8 The antennas are composed of Tx#1 and Tx#3. Each transmitting antenna group contains two transmitting antenna elements, which are equidistant in the vertical direction and equidistant in the horizontal direction. Figure 8 The antenna spacing in the horizontal direction is 2D. H Additionally, the vertical direction between the "first transmitting antenna group" and the "second transmitting antenna group" ( Figure 8 The interval in the vertical direction (e.g., 3D) V .

[0272] in addition, Figure 8 The receiving array antenna shown consists of the "first receiving antenna group" ( Figure 8 Rx#2, Rx#4) and "second receiving antenna group" ( Figure 8 The antennas are composed of Rx#1 and Rx#3. Each receiving antenna group contains two receiving antenna elements, which are equidistant in the vertical direction and spaced 3D apart in the horizontal direction. H Furthermore, the vertical spacing between the "first receiving antenna group" and the "second receiving antenna group" is, for example, 2D. V .

[0273] In other words, in Figure 8 In the middle, the vertical spacing between transmitting antenna groups (in Figure 8 3D V The horizontal antenna spacing within each receiving antenna group (in) Figure 8 3D H Same as above. Additionally, in Figure 8 In the middle, the horizontal antenna spacing within each transmitting antenna group (in Figure 8 2D H The vertical spacing between the antenna group and the receiving antenna group (in Figure 8 2D H )same.

[0274] In addition, Figure 8 In the middle, the 3D spacing between transmitting antenna groups V (Or, the antenna spacing within the receiving antenna group is 3D) H) and the antenna spacing within the transmitting antenna group is 2D H (Or, the spacing between receiving antenna groups is 2D) V The difference is D. H Or D V .

[0275] In addition, Figure 8 In the middle, the antenna spacing within the transmitting antenna group is 2D. H (D H (intervals that are integer multiples of each other) and the 3D antenna spacing within the receiving antenna group H (D H The difference between the intervals that are integer multiples of each other is D. H Additionally, in Figure 8 In the middle, multiple transmitting antenna groups are configured with 3D spacing. V (D V (intervals that are integer multiples of each other) and the spacing 2D between multiple receiving antenna groups. V (D V The difference between the intervals that are integer multiples of each other is D. V .

[0276] (2) Configuration of the virtual receiver array

[0277] According to the above Figure 8 The configuration of the virtual receiving array (virtual antenna VA#1 to virtual antenna VA#16) formed by the transmit and receive antenna configuration shown has the following characteristics.

[0278] Here, the configuration of the virtual receiving array can be expressed in the following way, based on the location of the transmitting antenna (the location of the power supply point) constituting the transmitting array antenna and the location of the receiving antenna (the location of the power supply point) constituting the receiving array antenna.

[0279]

[0280] Furthermore, mod(x, y) is the operator for calculating the remainder after division (modulo operation), which returns the remainder after dividing x by y. Additionally, ceil(x) is the operator that returns the value obtained by taking the nearest integer greater than or equal to x. Furthermore, in equation (7), the X-axis corresponds to... Figure 8 The horizontal direction (lateral direction) shown corresponds to the Y-axis. Figure 8 The vertical direction (longitudinal direction) is shown.

[0281] Here, the position coordinates of the transmitting antenna 106, which constitutes the transmitting array antenna, are set as (X... T_#n Y T_#n (where n = 1, ..., Nt), the position coordinates of the receiving antenna 202 constituting the receiving array antenna are set as (X... R_#m Y R_#m(where m = 1, ..., Na), and the position coordinates of the virtual antennas constituting the virtual receiving array are set as (X... V_#k Y V_#k (where k = 1, ..., Nt × Na). Furthermore, in equation (7), VA#1 is represented as the location reference (0, 0) of the virtual receiving array.

[0282] As an example, to illustrate Figure 8 The antenna configuration is shown.

[0283] The position coordinates of the transmitting antenna 106 constituting the transmitting array antenna are given by the position coordinates of the transmitting antenna Tx#1 (X). T_#1 Y T_#1 Based on the reference, the position coordinates (X) of the transmitting antenna Tx#2 are represented as follows. T_#2 Y T_#2 )=(X T_#1 Y T_#1 +3D V ), the position coordinates (X) of transmitting antenna Tx#3 T_#3 Y T_#3 )=(X T_#1 +2D H Y T_#1 ), the position coordinates (X) of transmitting antenna Tx#4 T_#4 Y T_#4 )=(X T_#1 +2D H Y T_#1 +3D V ).

[0284] Similarly, the position coordinates of the receiving antenna 202, which constitutes the receiving array antenna, are taken from the position coordinates of the receiving antenna Rx#1 (X R_#1 Y R_#1 Based on the reference, the position coordinates (X) of the receiving antenna Rx#2 are represented as follows. R_#2 Y R_#2 )=(X R_#1 Y R_#1 +2D V ), the position coordinates (X) of receiving antenna Rx#3 R_#3 Y R_#3 )=(X R_#1 +3D H Y R_#1 ), the position coordinates of receiving antenna Rx#4 (X R_#4 Y R_#4 )=(X R_#1 +3D H Y R_#1 +2D V ).

[0285] Based on the configuration of this transmitting array antenna and the receiving array antenna, the position coordinates (X) of virtual receiving arrays VA#1 to VA#16 are... V_#1 Y V_#1 )~(X V_#16 Y V_#16 The following are the details respectively.

[0286] (0, 0), (0, 3D) V (2D) H ,0),(2D H 3D V (0, 2D) V (0, 5D) V (2D) H 2D V (2D) H 5D V ), (3D) H ,0),(3D H 3D V ), (5D H ,0), (5D H 3D V ), (3D) H 2D V ), (3D) H 5D V ), (5D H 2D V ), (5D H 5D V )

[0287] Thus, in Figure 8 In the configuration of the virtual receiver array shown, each virtual receiver array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, resulting in a narrower main lobe and thus improved angular resolution.

[0288] In addition, such as Figure 8 As shown, virtual array elements VA#4, VA#7, VA#10, and VA#13, located near the center of the virtual receiving array, are arranged horizontally at angles D. H The spacing is closely arranged, and along the vertical direction at D V The spacing is closely spaced. As an example, in... Figure 8 In the middle, the interval D H and interval D V With a value of approximately 0.5λ, the virtual array elements VA#4, VA#7, VA#10, and VA#13 are arranged horizontally at a distance of D. H =0.5λ interval configuration, and along the vertical direction with D VA grid spacing of 0.5λ is used. This reduces the number of grating lobes. The effect of reducing grating lobes will be described later.

[0289] Furthermore, the configuration of the virtual receiver array does not depend on the positional relationship between the transmitter and receiver array antennas. Therefore, the positional relationship between the transmitter and receiver array antennas is not limited to... Figure 8 The configuration shown can be set arbitrarily. The other configuration structures described below are the same.

[0290] In addition, it can Figure 8 The horizontal and vertical configurations of the transmitted and received array antennas shown are configured as vertical and horizontal (e.g., making...). Figure 8 The same effect is achieved by rotating the original configuration by 90 degrees. The other configuration structures described below are the same.

[0291] In addition, Figure 8 The antenna configuration shown can also be interchanged between the transmitting array antenna and the receiving array antenna. For example, it is also possible to... Figure 8 The configuration of the receive array antenna shown is used as the configuration of the transmit array antenna, and will Figure 8 The configuration of the transmit array antenna shown is used as the configuration of the receive array antenna. Even if the configurations of the transmit and receive array antennas are interchanged, the same effect can be obtained because the virtual receive array is configured in the same way. The other configuration structures described below are also the same.

[0292] Here, as an example, to illustrate... Figure 8 Lieutenant General Interval D H and interval D V Let's assume the value is around 0.5λ. For example... Figure 8 As shown, in the transmitting antenna array and the receiving antenna array, the spacing between the antenna elements is 2D. H 3D H 2D V and 3D V One of the intervals. In other words, in Figure 8 In the middle, the 3D spacing between transmitting antenna groups V 3D antenna spacing within the receiving antenna group H The antenna spacing within the transmitting antenna group is 2D. H and the spacing 2D between receiving antenna groups V This is an interval longer than a wavelength of the radar signal (e.g., a radar carrier wave). Therefore, in Figure 8 In this design, the horizontal and vertical dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0293] Therefore, for example, it is possible to apply such as Figure 9A The antenna shown is as Figure 8 The antenna elements of at least one of the transmitting array antennas and receiving array antennas shown are as follows: Figure 9A The antenna shown uses a four-element subarray consisting of two planar patch antennas arranged horizontally and vertically. However, in Figure 9A In the middle, the antenna width W ANT <2D H And the antenna height H ANT <2D V .

[0294] In addition, Figure 8 In this case, the antenna spacing in the vertical direction of the transmitting array antenna is 3D. V It is greater than the horizontal antenna spacing of 2D. H Therefore, for example, it is possible to apply... Figure 9B The antenna shown is as Figure 8 The antenna elements of the transmitting array antenna shown are as follows: Figure 9B The antenna shown uses a subarray of six elements, consisting of three planar patch antennas arranged vertically and two planar patch antennas arranged horizontally. However, in Figure 9B In the middle, the antenna width W ANT <2D H And the antenna height H ANT <3D V .

[0295] In addition, Figure 8 In this case, the horizontal antenna spacing of the receiving array antenna is 3D. H It is greater than the vertical antenna spacing of 2D. V Therefore, for example, it is possible to apply... Figure 9C The antenna shown is as Figure 8 The antenna elements of the receiving array antenna shown are as follows: Figure 9C The antenna shown uses a subarray of six elements, consisting of two planar patch antennas arranged vertically and three planar patch antennas arranged horizontally. However, in Figure 9C In the middle, the antenna width W ANT <3D H And the antenna height H ANT <2D V .

[0296] Through Figure 8 The antenna configuration shown uses, for example Figure 9A , Figure 9B or Figure 9CThe subarray structure of the antenna shown can improve the antenna's directivity gain, thereby improving the detection performance (e.g., detection range) of the radar device 10. Furthermore, it is suitable for... Figure 8 The structure of the subarray of the antenna element shown is not limited to Figure 9A , Figure 9B and Figure 9C The structure shown, as long as it can... Figure 8 The subarray structure can be configured at the position shown as the phase center of the antenna element (in other words, the antenna system).

[0297] As an example, Figure 10 Indicates in Figure 8 The antenna elements of the transmitted array antenna shown employ [the following] Figure 9B The example shown is a subarray case. Figure 10 As shown, the transmitting array antenna consists of a 3D dimension in the vertical direction. V 2D Horizontal Dimensions H The subarray structure is composed of various antenna elements.

[0298] Thus, based on basic configuration 1, for example, it is possible to apply sizes greater than 1λ (e.g., in D). H =D V Antenna elements (in the case of 0.5λ) are used to enable close proximity (e.g., with D) in both the horizontal and vertical directions within a virtual receiver array. H Or D V Virtual antennas are configured at intervals. This reduces (in other words, suppresses) grating lobes and improves the antenna's directional gain.

[0299] The above describes an example of the antenna configuration in radar device 10.

[0300] Direction estimation unit 214 uses the configuration of the transceiver antenna described above (for example, refer to...). Figure 8 The virtual receiving array obtained (e.g., refer to) Figure 8 The received signal is processed for horizontal and vertical direction estimation in the following manner.

[0301] The component numbers (VA#) of the aforementioned virtual receiver array correspond to the virtual receiver array correlation vector h, which has been corrected for inter-antenna bias, as shown in equation (6). _after_cal The element indices of the column vector (k, fs, w). For example, Figure 8 The VA#1 shown corresponds to h _after_cal The first element h1(k, fs, w) of the column vector elements of (k, fs, w). Figure 8 The other VA#2 to VA#16 shown are the same.

[0302] In the arrival direction estimation in the horizontal and vertical directions, the direction estimation unit 214 changes the direction estimation evaluation function value within a specified angle range. The azimuth direction θ and elevation direction in the middle The spatial distribution is calculated. The direction estimation unit 214 extracts a predetermined number of the maximum peaks of the calculated spatial distribution in descending order, and outputs the azimuth and elevation directions of the maximum peaks as estimated arrival directions.

[0303] Furthermore, based on the arrival direction estimation algorithm, there are various methods for evaluating function values. Alternatively, estimation methods using array antennas, as disclosed in non-patent literature, can also be used.

[0304] (Refer to non-patent literature) Direction-of-arrival estimation using signal subspace modeling Cadzow, JA; Aerospace and Electronic Systems, IEEE Transactions on Volume: 28, Issue: 1 Publication Year: 1992, Page (s): 64-79

[0305] For example, beamforming can be represented as shown in the following formula. Furthermore, methods such as Capon and MUSIC can also be applied in the same way.

[0306] P(θ u ,φ v ,k,fs,w)=|a(θ u ,φ v ) H h _after_cal (k,fs,w)| 2 (8)

[0307] Here, the superscript H is the Hermitian transpose operator. Additionally, Indicates the direction relative to azimuth θ and elevation angle. The direction vector of the virtual receiving array of the arriving wave.

[0308] As described above, the direction estimation unit 214 outputs the calculated arrival direction estimate, the discrete time k and the Doppler frequency fsΔΦ when calculating the arrival direction estimate as radar positioning results.

[0309] Additionally, the azimuth direction θ u It is a vector that changes within the azimuth range used for arrival direction estimation, using a specified azimuth interval β1. For example, θ is set as follows: u.

[0310] θ u =θmin+uβ1, u=0,...,NU

[0311] NU=floor[(θmax-θmin) / β1]+1

[0312] Here, floor(x) is a function that returns the largest integer value that does not exceed the real number x.

[0313] in addition, It is a vector that varies within the elevation angle range used for direction of arrival estimation, based on a specified azimuth interval β2. For example, it can be set as follows:

[0314]

[0315] Furthermore, in this embodiment, the direction vector of the virtual receiving array is pre-calculated based on the configuration of the virtual receiving array VA#1, ..., VA#(Nt×Na). Here, direction vector Therefore, the radar reflected wave travels from the azimuth direction θ and the elevation direction. The complex response of the virtual receiving array under the condition of arrival is a column vector of element power (Nt×Na). Furthermore, the complex response of the virtual receiving array... This represents the phase difference calculated using geometric optics based on the element spacing between antennas.

[0316] Alternatively, the aforementioned time information k can also be converted into distance information and output. This can be achieved by using the following formula to convert the time information k into distance information R(k). Here, Tw represents the encoded transmission interval, L represents the pulse code length, and C0 represents the speed of light.

[0317]

[0318] Additionally, the Doppler frequency information (fsΔΦ) can also be converted into a relative velocity component and output. The Doppler frequency fsΔΦ can be converted into the relative velocity component vd(fs) using the following formula. Here, λ is the wavelength of the carrier frequency of the RF signal output from the wireless transmitter 105.

[0319]

[0320] Figure 11A and Figure 11B This shows an example of the direction estimation result when beamforming is used as the arrival direction estimation algorithm for the direction estimation unit 214. Figure 11A and Figure 11BThe output of the direction-of-arrival estimation evaluation function values ​​within the horizontal ±90 degree range and the vertical ±90 degree range, with the target ground truth set to 0 degrees horizontally and 0 degrees vertically, is plotted. Furthermore, calculations were performed with the directivity of each antenna set to omnidirectional.

[0321] Figure 11A Indicates use Figure 8 The transmit / receive antenna configuration shown (e.g., MIMO array configuration) (where D) H =0.5λ, D V An example of the direction estimation result when λ = 0.5. That is, in Figure 11A The conditions are that the horizontal and vertical antenna spacing of the transmitting antenna 106 reaches 1λ or more, and the horizontal and vertical antenna spacing of the receiving antenna 202 also reaches 1λ or more.

[0322] in addition, Figure 11B In order to Figure 11A For comparison, as an example, consider the case where the vertical antenna spacing of the transmitting antennas in the antenna configuration of the MIMO radar shown in Figure 1 is set to λ, and the horizontal antenna spacing of the receiving antennas is also set to λ (i.e., D...). V =λ,D H The direction estimation result of =λ).

[0323] exist Figure 11B In this process, grid lobes are generated along the horizontal and vertical directions, outside of the target's true horizontal and vertical dimensions. In contrast, in... Figure 11A In this study, it was confirmed that the grating lobes were reduced in directions other than the horizontal and vertical 0 degrees of the target true value. For example, in... Figure 11A In the meantime, the ratio of the peak power of the highest sidelobe (excluding the main lobe) in directions other than 0 degrees horizontally and vertically to the peak power of the main lobe in directions other than 0 degrees horizontally and vertically (PSLR) is about 0.44.

[0324] As described above, by using Figure 8 The MIMO array configuration shown allows for the configuration of horizontal and vertical antenna spacing in the virtual receiver array with an element size of approximately 1λ in the longitudinal or transverse directions, even when the antennas used as transmit and receive array antennas are approximately 1λ apart. This enables the configuration to reduce grating lobes. Furthermore, for example, as... Figure 8 As shown, the virtual array elements of the virtual receiver array are configured without repetition, thus enabling the aperture length of the virtual receiver array to be increased, thereby improving the angular resolution.

[0325] Furthermore, an antenna with a subarray structure having element dimensions of at least 1λ in both the longitudinal and transverse directions can be used as the antenna element for both the transmitting antenna 106 and the receiving antenna 202. This improves the antenna's directional gain, thereby enhancing the detection performance (e.g., detection range) of the radar device 10.

[0326] Furthermore, MIMO array configurations are not limited to Figure 8 The example shown. For example, substitution can also be used. Figure 8 The antenna configuration shown is formed by the horizontal and vertical directions. In this case, the virtual receiver array configuration can be swapped. Figure 8 The configuration is formed by the horizontal and vertical directions. Therefore, a swap can be obtained. Figure 8 and Figure 8 The angular separation performance obtained in the horizontal and vertical directions. The MIMO array configuration described below can also be configured by swapping the horizontal and vertical directions.

[0327] <Example 1 of the basic configuration>

[0328] In basic configuration 1 (for example, Figure 8 The document describes the case where the number of transmitting antennas 106 is set to 4 elements (Nt = 4), and the number of receiving antennas 202 is set to 4 elements (Nat = 4). However, the number of transmitting antennas Nt and the number of receiving antennas Na are not limited to these numbers.

[0329] In Variation 1 of Basic Configuration 1, the transmitting array antenna is similar to that in Basic Configuration 1, for example, with a vertical spacing of 3D. V The system comprises a first transmitting antenna group and a second transmitting antenna group. Furthermore, each transmitting antenna group, similar to the basic configuration 1, includes multiple transmitting antenna elements. These multiple transmitting antenna elements are equidistant in the vertical direction and spaced 2D apart in the horizontal direction. H .

[0330] Furthermore, in variation 1 of basic configuration 1, the receiving array antenna is similar to that in basic configuration 1, for example, consisting of a vertical spacing of 2D. V It consists of multiple receiving antenna groups. Furthermore, each receiving antenna group contains multiple receiving antenna elements, which are equidistant in the vertical direction and spaced 3D apart in the horizontal direction. H .

[0331] In other words, in variation 1 of basic configuration 1, similarly to basic configuration 1, the vertical spacing between the transmitting antenna groups (here, 3D) is... V The horizontal antenna spacing within each receiving antenna group (in 3D) HThe same applies. Additionally, the horizontal antenna spacing within each transmitting antenna group (here, 2D) is the same. H The vertical spacing between the antenna array and the receiving antenna group (here, 2D) H )same.

[0332] Additionally, the number of transmitting antenna groups will be denoted as "N" below. TxGroup The number of transmitting antennas in each transmitting antenna group is represented as "N". TxGroup_ANT Additionally, the number of receiving antenna groups is expressed as "N". RxGroup The number of transmitting antennas contained in each receiving antenna group is represented as "N". RxGroup_ANT ".

[0333] In variation 1 of basic configuration 1, the method based on N can be adopted. TxGroup_ANT and N RxGroup The value increases the configuration of the number of antennas in the MIMO array.

[0334] Figure 12 N represents TxGroup_ANT =4, N RxGroup Examples of configurations for transmitting antenna 106 and receiving antenna 202 when the number of antennas is 2, and examples of configurations for a virtual receiving array.

[0335] Figure 13 N represents TxGroup_ANT =2, N RxGroup Examples of configurations for transmitting antenna 106 and receiving antenna 202 when the number of antennas is 3, and examples of configurations for a virtual receiving array.

[0336] Figure 14 N represents TxGroup_ANT =4, N RxGroup Examples of configurations for transmitting antenna 106 and receiving antenna 202 when the number of antennas is 3, and examples of configurations for a virtual receiving array.

[0337] In addition, Figure 12 , Figure 13 and Figure 14 In, N TxGroup =2, and N RxGroup_ANT =2.

[0338] exist Figure 12 , Figure 13 and Figure 14 In the various MIMO array configurations shown, for example, D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0339] Additionally, for example, in Figure 12 , Figure 13 and Figure 14 In each of the virtual receiver arrays shown, each virtual array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, thereby improving the angular resolution.

[0340] In addition, it is possible to use D H D V Intervals, closely configured in Figure 12 , Figure 13 and Figure 14 The virtual array elements shown are located near the center of each virtual receiver array. Additionally, D... H D V The number of closely spaced virtual array elements depends on N. TxGroup_ANT and N RxGroup And increase.

[0341] For example, in a virtual receiver array, in the horizontal direction, (N TxGroup_ANT ×N RxGroup_ANT ) - 2 virtual array elements in D H Alternating arrangement, in the vertical direction, (N) RxGroup ×N TxGroup ) - 2 virtual array elements in D V Arranged at intervals. Near the center of the virtual receiver array, at intervals of D... H D V The more closely spaced the virtual array elements are arranged, the better the effect of reducing grating lobes and side lobes will be.

[0342] In addition, N TxGroup_ANT N RxGroup_ANT The larger the value of N, the greater the number of virtual array elements arranged horizontally. Therefore, the aperture length of the horizontal virtual receiving array can be increased, thereby improving the horizontal angular resolution. Similarly, N... RxGroup N RxGroup The larger the aperture, the greater the number of virtual array elements arranged along the vertical direction. Therefore, the aperture length of the virtual receiving array in the vertical direction can be increased, thereby improving the angular resolution in the vertical direction.

[0343] Figure 15 For example, in such Figure 14 The diagram shows a MIMO array configuration using 8 transmit antennas 106 (Nt=8) and 6 receive antennas 202 (Na=6). TxGroup_ANT =4, N TxGroup =2, N RxGroup =3, N RxGroup_ANT =2,D H =0.5λ, D VIn the case of λ = 0.5λ, an example of the direction estimation result is given when beamforming is used as the arrival direction estimation algorithm for the direction estimation unit 214. Furthermore, calculations were performed with the directivity of each antenna set to omnidirectional.

[0344] exist Figure 15 The output of the arrival direction estimation evaluation function value is plotted under the conditions that the target true value is set to 0 degrees horizontally and 0 degrees vertically, within the range of ±90 degrees in the horizontal direction and ±90 degrees in the vertical direction.

[0345] exist Figure 15 In this process, it can be confirmed that in directions other than the horizontal and vertical 0 degrees of the target true value, such as with... Figure 11A Compared to this, the number of grid lobes is reduced. For example, in Figure 15 In the study, the peak power ratio (PSLR) of the highest side lobe (excluding the main lobe) relative to the peak power of the main lobe in the horizontal and vertical directions (0 degrees) is approximately 0.22.

[0346] Therefore, it can be confirmed that Figure 14 In the case of (N) TxGroup_ANT =4, N RxGroup =3), and Figure 8 (N TxGroup_ANT =2, N RxGroup =2) case (for example, refer to Figure 11A Compared to (in both cases, N), TxGroup =2, N RxGroup_ANT =2), by increasing N TxGroup_ANT and N RxGroup This improves the effect of reducing side lobes. Additionally, in Figure 15 In the middle, it is possible to confirm with Figure 11A In comparison, the peak of the main lobe also becomes sharper, by increasing N TxGroup_ANT and N RxGroup Angular resolution is improved.

[0347] <Example 2 of Basic Configuration 1>

[0348] The following describes antenna configuration methods 1-2A and 1-2B in variation 2 of basic configuration 1.

[0349] (Configuration Method 1-2A)

[0350] In Variation 1 of Basic Configuration 1, the following situation is illustrated: by increasing the number N of the receiving antenna groups contained in the receiving array antenna... RxGroup Increase the number of virtual array elements arranged along the vertical direction. Here, as long as N... RxGroup ≥3, by increasing the number N of transmitting antenna groups in the transmitting array antenna. TxGroupIt can also increase the number of virtual array elements arranged vertically in the virtual receiver array.

[0351] In this case, although the vertical antenna spacing of the transmitting antenna array can be set to a fixed value (e.g., 3D), V However, it depends on the number of receiving antenna groups N. RxGroup The virtual receiver array configuration will become a repeated configuration of the virtual array elements.

[0352] Therefore, in order to configure the virtual receiver array in a way that does not contain duplicate virtual array elements, for example, the interval D described below can be used. TxGroupV This refers to the even-numbered antenna spacing in the vertical direction of the transmitting antenna group.

[0353] D TxGroupV =D V (2N RxGroup -3) (11)

[0354] For example, in N RxGroup When D = 3, TxGroupV =3D V In N RxGroup When D = 4, TxGroupV =5D V .

[0355] For example, in the number N of transmitting antenna groups TxGroup When the value is 3, the spacing between the three transmitting antenna groups is set to {3D}. V D TxGroupV Additionally, regarding the number N of transmitting antenna groups... TxGroup When the number of antennas is 4, the spacing between the four transmitting antenna groups is set to {3D}. V D TxGroupV 3D V Similarly, when the number of transmitting antenna groups N... RxGroup_ANT When the value is 5, the spacing between the 5 transmitting antenna groups is set to {3D}. V D TxGroupV 3D V D TxGroupV}

[0356] Figure 16 N represents TxGroup =4, N TxGroup_ANT =4, N RxGroup =3, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 when their numbers are equal to 2, and examples of configurations for a virtual receiving array. Figure 16 In equation (11), D TxGroupV =3D V.

[0357] in addition, Figure 17 N represents TxGroup =4, N TxGroup_ANT =4, N RxGroup =4, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 when their numbers are equal to 2, and examples of configurations for a virtual receiving array. Figure 17 In equation (11), D TxGroupV =5D V .

[0358] Furthermore, unequal intervals (e.g., greater than D) can be included near the center of the virtual receiver array. H and D V In the case of the interval) configuration, D TxGroupV It can also be a value larger than that in equation (11).

[0359] (Configuration Method 1-2B)

[0360] In Variation 1 of Basic Configuration 1, the following situation is illustrated: by increasing the number N of transmitting antennas in each transmitting antenna group of the transmitting array antenna... TxGroup_ANT Increase the number of virtual array elements arranged horizontally. Here, as long as N... TxGroup_ANT ≥3, by increasing the number N of receiving antennas in the receiving antenna group of the receiving array antenna. RxGroup_ANT It can also increase the number of virtual array elements arranged horizontally in the virtual receiver array.

[0361] In this case, although the horizontal antenna spacing of the receiving antenna group can also be set to a fixed value (e.g., 3D), H However, this depends on the number of transmitting antennas N contained in the transmitting antenna group. TxGroup_ANT The virtual receiver array configuration will become a repeated configuration of the virtual array elements.

[0362] Therefore, in order to configure the virtual receiver array in a way that does not contain duplicate virtual array elements, for example, the interval D described below can be used. RxAntH This refers to the even-numbered antenna spacing in the horizontal direction of the receiving antennas contained in the receiving antenna group.

[0363] D RxAntH =D H (2N TxGroup_ANT -3) (12)

[0364] For example, in N TxGroup_ANT When D = 3, RxAntH =3D H In NTxGroup_ANT When D = 4, RxAntH =5D H .

[0365] For example, in the number N of receiving antennas contained in the receiving antenna group RxGroup_ANT When the value is 3, the antenna spacing of the three receiving antennas is set to {3D}. H D RxAntH Additionally, when the number of receiving antennas N... RxGroup_ANT When the number of antennas is 4, the antenna spacing of the four receiving antennas is set to {3D}. H D RxAntH 3D H Similarly, with N receiving antennas... RxGroup_ANT When the number of antennas is 5, the antenna spacing of the 5 receiving antennas is set to {3D}. H D RxAntH 3D H D RxAntH}

[0366] Figure 18 N represents TxGroup =2, N TxGroup_ANT =3, N RxGroup =2, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 when the number of antennas is 4, and examples of configurations for a virtual receiving array. Figure 18 In equation (12), D RxAntH =3D H .

[0367] Figure 19 N represents TxGroup =2, N TxGroup_ANT =4, N RxGroup =2, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 when the number of antennas is 4, and examples of configurations for a virtual receiving array. Figure 19 In equation (12), D RxAntH =5D H .

[0368] Furthermore, unequal intervals (e.g., greater than D) can be included near the center of the virtual receiver array. H and D V In the case of the interval) configuration, D RxAntH It can also be a value larger than that in equation (12).

[0369] The above describes configuration method 1-2A and configuration method 1-2B in variant example 2 of basic configuration 1.

[0370] For example, in Figures 16-19In the transmit / receive antenna configuration shown (e.g., MIMO array configuration), D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0371] Additionally, for example, in Figures 16-19 In each of the virtual receiver arrays shown, each virtual array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, thereby improving the angular resolution.

[0372] Additionally, for example, it is possible to use D H D V Intervals, closely configured in Figures 16-19 The virtual array elements shown are located near the center of the virtual receiver array. Additionally, D... H D V The number of closely spaced virtual array elements depends on N. TxGroup N TxGroup_ANT N RxGroup and N RxGroup_ANT And increase.

[0373] For example, in a virtual receiver array, in the horizontal direction, (N TxGroup_ANT ×N RxGroup_ANT ) - 2 virtual array elements in D H Alternating arrangement, in the vertical direction, (N) RxGroup ×N TxGroup ) - 2 virtual array elements in D V Arranged at intervals. Near the center of the virtual receiver array, at intervals of D... H D V The more closely spaced virtual array elements are added, the better the effect of reducing grating lobes and side lobes can be.

[0374] In addition, N TxGroup_ANT N RxGroup_ANT The larger the value of N, the greater the number of virtual array elements arranged horizontally. Therefore, the aperture length of the horizontal virtual receiving array can be increased, thereby improving the horizontal angular resolution. Similarly, N... TxGroup N RxGroup The larger the aperture, the greater the number of virtual array elements arranged along the vertical direction. Therefore, the aperture length of the virtual receiving array in the vertical direction can be increased, thereby improving the angular resolution in the vertical direction.

[0375] Furthermore, in variation 2 of basic configuration 1, a configuration combining configuration method 1-2A and configuration method 1-2B can also be used. Figure 20N represents TxGroup =4, N TxGroup_ANT =4, N RxGroup =4, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 with a configuration of 4 antennas, and examples of configurations for a virtual receiving array. Figure 20 In equation (11), D TxGroupV =5D H D in equation (12) RxAntH =5D H Therefore, the combined effect of configuration methods 1-2A and 1-2B can be obtained.

[0376] <Example 3 of the variation of basic configuration 1>

[0377] The following describes antenna configuration methods 1-3A, 1-3B, and 1-3C in variation 3 of basic configuration 1.

[0378] (Configuration methods 1-3A)

[0379] Basic Configuration 1 describes a configuration where the horizontal positions of the transmitting antennas in each transmitting antenna group are identical. However, this is not a limitation; the horizontal configuration of the transmitting antennas in each transmitting antenna group can also differ.

[0380] For example, in a transmitting array antenna, the horizontal positions can be offset (in other words, shifted). H The first and second transmitting antenna groups are configured with their respective transmitting antennas.

[0381] offset along the horizontal direction D H The direction is relative to each transmitting antenna in the first transmitting antenna group, or it can be any direction to the right or left of each transmitting antenna in the second transmitting antenna group.

[0382] Figure 21 This indicates that the transmit antennas (e.g., Tx#1, Tx#3) in the second transmit antenna group of the transmit array are offset to the right by D relative to the transmit antennas (e.g., Tx#2, Tx#4) in the first transmit antenna group. H Examples of configurations for transmitting antenna 106 and receiving antenna 202, and examples of configurations for virtual receiving arrays.

[0383] exist Figure 21 In the middle, the horizontal positions of Tx#1 and Tx#2 differ by D. H Additionally, the horizontal positions of Tx#3 and Tx#4 differ by D. H .

[0384] (Configuration methods 1-3B)

[0385] In Basic Configuration 1, it was described that the horizontal positions of the receiving antennas in each receiving antenna group within the receiving array are the same. However, this is not a limitation; the horizontal configuration of the receiving antennas in each receiving antenna group can also differ.

[0386] For example, in a receiving array antenna, the horizontal positions can be offset by D. H The first receiving antenna group and the second receiving antenna group are configured with their respective receiving antennas.

[0387] offset along the horizontal direction D H The direction is relative to each receiving antenna in the first receiving antenna group, or it can be any direction to the right or left of each receiving antenna in the second receiving antenna group.

[0388] Figure 22 This indicates that the receiving antennas (e.g., Rx#1, Rx#3) in the second receiving antenna group of the receiving antenna array are offset to the right by D relative to the receiving antennas (e.g., Rx#2, Rx#4) in the first receiving antenna group. H Examples of configurations for transmitting antenna 106 and receiving antenna 202, and examples of configurations for virtual receiving arrays.

[0389] exist Figure 22 In the middle, the horizontal positions of Rx#1 and Rx#2 differ by D. H Additionally, the horizontal positions of Rx#3 and Rx#4 differ by D. H .

[0390] (Configuration methods 1-3C)

[0391] Configuration method 1-3C is a combination of configuration method 1-3A and configuration method 1-3B.

[0392] For example, in a transmit array antenna, the horizontal positions of the first transmit antenna group and the second transmit antenna group are offset by D. H The transmitting antenna is configured accordingly. Similarly, the horizontal positions of the first receiving antenna group and the second receiving antenna group in the receiving array are offset by D. H Configure the receiving antenna on the ground.

[0393] In addition, D is offset horizontally. H The direction can be, for example, relative to the transmitting antennas in the first transmitting antenna group, or any direction to the right or left of the transmitting antennas in the second transmitting antenna group. Additionally, it can be offset by D along the horizontal direction. HThe direction can be any direction relative to the receiving antennas in the first receiving antenna group, or to the right or left of the receiving antennas in the second receiving antenna group.

[0394] Figure 23 Examples of configurations for the transmitting antenna 106 and receiving antenna 202 in configuration methods 1-3C, and an example of a configuration for a virtual receiving array. Figure 23 In the transmit array antenna, each transmit antenna (e.g., Tx#1, Tx#3) in the second transmit antenna group is offset to the left by D relative to each transmit antenna (e.g., Tx#2, Tx#4) in the first transmit antenna group. H Location configuration. Additionally, in Figure 23 In the receiving antenna array, each receiving antenna in the second receiving antenna group (e.g., Rx#1, Rx#3) is offset to the left by D relative to each receiving antenna in the first receiving antenna group (e.g., Rx#2, Rx#4). H Location configuration.

[0395] Figure 24 Examples of configurations for the transmitting antenna 106 and receiving antenna 202 in configuration methods 1-3C, and an example of a configuration for a virtual receiving array. Figure 24 In the transmit array antenna, each transmit antenna (e.g., Tx#1, Tx#3) in the second transmit antenna group is offset to the left by D relative to each transmit antenna (e.g., Tx#2, Tx#4) in the first transmit antenna group. H Location configuration. Additionally, in Figure 24 In the receiving array antenna, each receiving antenna (e.g., Rx#1, Rx#3) in the second receiving antenna group is offset to the right by D relative to each receiving antenna (e.g., Rx#2, Rx#4) in the first receiving antenna group. H Location configuration.

[0396] For example, in the receiving antenna group and the transmitting antenna group, the antennas will be offset by D along the horizontal direction. H The direction is set to different directional configurations (e.g., Figure 24 Compared to this, in the receiving antenna group and the transmitting antenna group, the horizontal offset D is made H Configurations with the same orientation (e.g., Figure 23 It will configure the virtual receiver array elements more closely near the center of the virtual receiver array configuration, which is therefore more appropriate.

[0397] The above describes configuration methods 1-3A to 1-3C respectively.

[0398] For example, in Figures 21-24 In the transmit / receive antenna configuration shown (e.g., MIMO array configuration), DH and D V The value is set to approximately 0.5λ. Therefore, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 are designed to be approximately 1λ.

[0399] Therefore, in variation 3 of basic configuration 1, for example, it is possible to apply... Figure 9A The antenna shown uses four elements arranged in a planar patch antenna with two elements arranged in a horizontal and vertical direction to form a sub-array (where the antenna width W). ANT <2D H Antenna height H ANT <2D V (Not shown).

[0400] In addition, the vertical spacing between the transmitting antenna groups is 3D. V The horizontal spacing between the transmitting antennas within each transmitting antenna group is 2D. H The vertical spacing of the transmitting array antennas is greater than the horizontal spacing. Therefore, in variation 3 of basic configuration 1, for example, it is possible to apply... Figure 9B The antenna shown is composed of six elements forming a subarray, consisting of a planar patch antenna with three elements arranged vertically and two elements arranged horizontally (where the antenna width W). ANT <2D H Antenna height H ANT <3D V ).

[0401] Furthermore, in variation 3 of basic configuration 1, for at least one of the transmit array antennas and receive array antennas, the horizontal positions of the transmit antennas in each transmit antenna group or the receive antennas in each receive antenna group are different from each other. Therefore, in variation 3 of basic configuration 1, as long as the horizontal direction W of the subarray is different... ANT The component size is smaller than D H Then the element size in the longitudinal direction of the subarray can be any size.

[0402] For example, Figure 25A This illustrates an example of a subarray consisting of a planar patch antenna with eight elements arranged vertically and a planar patch antenna with one element arranged horizontally. Furthermore, the structure of the subarray is not limited to... Figure 25A The structure shown.

[0403] in addition, Figure 25B Indicates to Figure 23 or Figure 24 The transmitted antenna array shown uses Figure 25A The example shown is of a subarray. In addition, besides... Figure 25B In addition to the transmitting array antenna shown, such as Figure 25C As shown, a power-free component (virtual component) can also be configured. Using a power-free component, the effects of inter-antenna coupling caused by adjacent antennas can be uniformized, thereby uniformizing the pointing characteristics of each transmitting antenna (Tx#1~Tx#4). Furthermore, by setting a power-free component, the effects of electrical characteristics such as antenna radiation, impedance matching, or isolation can be made consistent. Moreover, the configuration of the power-free component is not limited to... Figure 25C The location and size of the unpowered component can be configured without physical interference with the antennas.

[0404] Thus, by using an antenna with a subarray structure in the antenna configuration of the variation 3 of the basic configuration 1, the directional gain of the antenna can be improved, thereby improving the detection performance (e.g., detection range) of the radar device 10.

[0405] Furthermore, in variation 3 of basic configuration 1, the virtual array elements of the virtual receiving array are not repeatedly configured, thus enabling the aperture length of the virtual receiving array to be increased, thereby improving the angular resolution.

[0406] (A combination of variation 3 and variation 1)

[0407] Furthermore, the modified example 3 of the basic configuration 1 can also be combined with the modified example 1 of the basic configuration 1.

[0408] For example, it can be configured as follows: relative to the configuration of the transmit array antenna in Variation 1 of Basic Configuration 1, the horizontal positions of each transmit antenna in the transmit antenna group are further offset by D. H .

[0409] Similarly, for example, it can be configured such that, relative to the configuration of the receiving array antenna in Variation 1 of Basic Configuration 1, the horizontal positions of each receiving antenna in the receiving antenna group are further offset by D. H .

[0410] Figures 26-30 This illustrates an example of antenna configuration in a combination of Modification 3 and Modification 1.

[0411] Figure 26 N represents TxGroup =2, N TxGroup_ANT =4, N RxGroup =3, N RxGroup_ANT =2, and the horizontal positions of the transmitting antennas in the transmitting antenna group are offset by D. H Examples of configurations for transmitting antenna 106 and receiving antenna 202, and examples of configurations for virtual receiving arrays.

[0412] in addition, Figure 27 N represents TxGroup =2, N TxGroup_ANT =4, N RxGroup =3, N RxGroup_ANT =2, and the horizontal positions of the receiving antennas in the receiving antenna group are offset by D. H Examples of configurations for transmitting antenna 106 and receiving antenna 202, and examples of configurations for virtual receiving arrays.

[0413] in addition, Figure 28 N represents TxGroup =2, N TxGroup_ANT =4, N RxGroup =3, N RxGroup_ANT =2, which offsets the horizontal positions of the transmitting antennas in the transmitting antenna group by D. H Furthermore, the horizontal positions of the receiving antennas in the receiving antenna group are offset by D. H Examples of configurations for the transmitting antenna 106 and the receiving antenna 202, and an example of a configuration for a virtual receiving array. Figure 28 In the second transmitting antenna group, each transmitting antenna (e.g., Tx#1, Tx#3, Tx#5, Tx#7) is offset to the left by D relative to each transmitting antenna (e.g., Tx#2, Tx#4, Tx#6, Tx#8) in the first transmitting antenna group. H Location configuration. Additionally, in Figure 28 In the receiving antenna array, each receiving antenna in the second receiving antenna group (e.g., Rx#2, Rx#5) is offset to the left by D relative to each receiving antenna in the first receiving antenna group (e.g., Rx#3, Rx#6). H Location configuration. Additionally, in Figure 28 In the middle, each receiving antenna in the third receiving antenna group (e.g., Rx#1, Rx#4) is offset to the left by D relative to each receiving antenna in the second receiving antenna group. H Location configuration.

[0414] in addition, Figure 29 N represents TxGroup =2, N TxGroup_ANT =4, N RxGroup =3, N RxGroup_ANT =2, which offsets the horizontal positions of the transmitting antennas in the transmitting antenna group by D. H Furthermore, the horizontal positions of the receiving antennas in the receiving antenna group are offset by D. H Examples of configurations for the transmitting antenna 106 and the receiving antenna 202, and an example of a configuration for a virtual receiving array. Figure 29In the second transmitting antenna group, each transmitting antenna (e.g., Tx#1, Tx#3, Tx#5, Tx#7) is offset to the right by D relative to each transmitting antenna (e.g., Tx#2, Tx#4, Tx#6, Tx#8) in the first transmitting antenna group. H Location configuration. Additionally, in Figure 29 In the receiving antenna array, each receiving antenna in the second receiving antenna group (e.g., Rx#2, Rx#5) is offset to the left by D relative to each receiving antenna in the first receiving antenna group (e.g., Rx#3, Rx#6). H Location configuration. Additionally, in Figure 29 In the middle, each receiving antenna in the third receiving antenna group (e.g., Rx#1, Rx#4) is offset to the left by D relative to each receiving antenna in the second receiving antenna group. H Location configuration.

[0415] For example, in Figures 26-29 In each MIMO array configuration shown, D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be 1λ or larger.

[0416] Additionally, for example, in Figures 26-29 In each of the virtual receiver arrays shown, each virtual array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, thereby improving the angular resolution.

[0417] Furthermore, even if the horizontal positions of each transmitting antenna are offset between the first and second transmitting antenna groups in the transmitting array antenna, D H In the case of a ground configuration, or by offsetting the horizontal positions of each receiving antenna in the receiving array antenna group by D between the first and second receiving antenna groups. H Even when configured locally, it can still be used with D H D V The virtual array elements are spaced out and closely arranged near the center of the virtual receiver array. Additionally, with D... H D V The number of closely spaced virtual array elements will, for example, depend on N. TxGroup_ANT and N RxGroup And increase.

[0418] For example, in a virtual receiver array, in the horizontal direction, (N TxGroup_ANT ×N RxGroup_ANT ) - 2 virtual array elements in D H Alternating arrangement, in the vertical direction, (N)RxGroup ×N TxGroup ) - 2 virtual array elements in D V Arranged at intervals. Near the center of the virtual receiver array, at intervals of D... H D V The more closely spaced the virtual array elements are arranged, the better the effect of reducing grating lobes and side lobes will be.

[0419] In addition, N TxGroup_ANT The larger the value of N, the greater the number of virtual array elements arranged horizontally. Therefore, the aperture length of the horizontal virtual receiving array can be increased, thereby improving the horizontal angular resolution. Similarly, N... RxGroup The larger the aperture, the greater the number of virtual array elements arranged along the vertical direction. Therefore, the aperture length of the virtual receiving array in the vertical direction can be increased, thereby improving the angular resolution in the vertical direction.

[0420] also, Figure 28 and Figure 29 This refers to the situation where the number of receiving antenna groups N is... RxGroup When the number of antenna groups is 3 or more, the horizontal positions of the receiving antennas in each receiving antenna group are staggered in a fixed direction (right or left). However, the direction of staggering the horizontal positions of the receiving antennas is not limited to this. For example, when the number of receiving antenna groups is N... RxGroup In cases where the number is 3 or higher, the horizontal positions of the receiving antennas in each receiving antenna group can be shifted to the right or left.

[0421] Figure 30 N represents TxGroup =2, N TxGroup_ANT =4, N RxGroup =3, N RxGroup_ANT =2, which offsets the horizontal positions of the transmitting antennas in the transmitting antenna group by D. H Furthermore, the horizontal positions of the receiving antennas in the receiving antenna group are offset by D. H Examples of configurations for the transmitting antenna 106 and the receiving antenna 202, and an example of a configuration for a virtual receiving array. Figure 30 In the second transmitting antenna group, each transmitting antenna (e.g., Tx#1, Tx#3, Tx#5, Tx#7) is offset to the left by D relative to each transmitting antenna (e.g., Tx#2, Tx#4, Tx#6, Tx#8) in the first transmitting antenna group. H Location configuration. Additionally, in Figure 30In the receiving antenna array, each receiving antenna in the second receiving antenna group (e.g., Rx#2, Rx#5) is offset to the left by D relative to each receiving antenna in the first receiving antenna group (e.g., Rx#3, Rx#6). H Location configuration. Additionally, in Figure 30 In the middle, each receiving antenna in the third receiving antenna group (e.g., Rx#1, Rx#4) is offset to the right by D relative to each receiving antenna in the second receiving antenna group. H Location configuration.

[0422] exist Figure 30 In the antenna configuration, it is also possible to use D H D V The virtual array elements are spaced out and closely arranged near the center of the virtual receiver array. Additionally, with D... H D V The number of closely spaced virtual array elements will, for example, depend on N. TxGroup_ANT and N RxGroup And increase. For example, in the horizontal direction, (N) TxGroup_ANT ×N RxGroup_ANT ) - 2 virtual array elements in D H Alternating arrangement, in the vertical direction, (N) RxGroup ×N TxGroup ) - 2 virtual array elements in D V Arranged at intervals. Near the center of the virtual receiver array, at intervals of D... H D V The more closely spaced virtual array elements are added, the better the effect of reducing grating lobes and side lobes can be.

[0423] (A combination of variation 3 and variation 2)

[0424] In addition, variation 3 of basic configuration 1 can also be combined with variation 2 of basic configuration 1.

[0425] For example, it can be configured as follows: relative to the configuration of the transmit array antenna in variant 2 of basic configuration 1, the horizontal positions of each transmit antenna in the transmit antenna group are further offset by D. H .

[0426] Similarly, for example, it can be configured such that, relative to the configuration of the receiving array antenna in variant 2 of basic configuration 1, the horizontal positions of each receiving antenna in the receiving antenna group are further offset by D. H .

[0427] Furthermore, regarding the number N of transmitting antenna groups TxGroupWhen the number is 3 or higher, the horizontal positions of each transmitting antenna in each transmitting antenna group can be staggered in a fixed direction (right or left). Alternatively, the direction in which the horizontal positions of each transmitting antenna in each transmitting antenna group are staggered to the right or left can be changed according to the transmitting antenna group.

[0428] Figure 31 and Figure 32 This illustrates an example of the antenna configuration in a combination of Modification 3 and Modification 2.

[0429] Figure 31 N represents TxGroup =4, N TxGroup_ANT =4, N RxGroup =4, N RxGroup_ANT =2, and the horizontal positions of the antennas in the transmitting and receiving antenna groups are offset by D. H Examples of configurations for the transmitting antenna 106 and the receiving antenna 202, and an example of a configuration for a virtual receiving array. Figure 31 In equation (11), D TxGroupV =5D V .

[0430] exist Figure 31 In the transmit antenna array, each transmit antenna in the second transmit antenna group (e.g., Tx3, Tx#7, Tx#11, Tx#15) is offset to the left by D relative to each transmit antenna in the first transmit antenna group (e.g., Tx#4, Tx#8, Tx#12, Tx#16). H Location configuration. Additionally, in Figure 31 In the third transmitting antenna group, each transmitting antenna (e.g., Tx2, Tx#6, Tx#10, Tx#14) is offset to the left by D relative to each transmitting antenna in the second transmitting antenna group. H Location configuration. Additionally, in Figure 31 In the fourth transmitting antenna group, each transmitting antenna (e.g., Tx1, Tx#5, Tx#9, Tx#13) is offset to the left by D relative to each transmitting antenna in the third transmitting antenna group. H Location configuration.

[0431] In addition, Figure 31 In the receiving array antenna, each receiving antenna in the second receiving antenna group (e.g., Rx#3, Rx#7) is offset to the left by D relative to each receiving antenna in the first receiving antenna group (e.g., Rx#4, Rx#8). H Location configuration. Additionally, in Figure 31In the middle, each receiving antenna in the third receiving antenna group (e.g., Rx#2, Rx#6) is offset to the left by D relative to each receiving antenna in the second receiving antenna group. H Location configuration. Additionally, in Figure 31 In the middle, each receiving antenna in the fourth receiving antenna group (e.g., Rx#1, Rx#5) is offset to the left by D relative to each receiving antenna in the third receiving antenna group. H Location configuration.

[0432] then, Figure 32 N represents TxGroup =2, N TxGroup_ANT =4, N RxGroup =2, N RxGroup_ANT =4, and the horizontal positions of the antennas in the transmitting and receiving antenna groups are offset by D. H Examples of configurations for transmitting antenna 106 and receiving antenna 202, and examples of configurations for a virtual receiving array. Figure 32 In equation (12), D RxGroupH =5D H .

[0433] exist Figure 32 In the second transmitting antenna group, each transmitting antenna (e.g., Tx#1, Tx#3, Tx#5, Tx#7) is offset to the left by D relative to each transmitting antenna (e.g., Tx#2, Tx#4, Tx#6, Tx#8) in the first transmitting antenna group. H Location configuration. Additionally, in Figure 32 In the receiving array antenna, the receiving antennas (e.g., Rx#1, Rx#3, Rx#5, Rx#7) in the second receiving antenna group are offset to the left by D relative to the receiving antennas (e.g., Rx#2, Rx#4, Rx#6, Rx#8) in the first receiving antenna group. H Location configuration.

[0434] For example, in Figure 31 and Figure 32 In each MIMO array configuration shown, D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be 1λ or more.

[0435] Additionally, for example, in Figure 31 and Figure 32 In each of the virtual receiver arrays shown, each virtual array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, thereby improving the angular resolution.

[0436] In addition, it is possible to use D H D V Intervals, closely configured in Figure 31 and Figure 32 The virtual array elements shown are located near the center of the virtual receiver array. Additionally, D... H D V The number of closely spaced virtual array elements will, for example, depend on N. TxGroup N TxGroup_ANT N RxGroup and N RxGroup_ANT And increase.

[0437] For example, in the horizontal direction, (N) TxGroup_ANT ×N RxGroup_ANT ) - 2 virtual array elements in D H Alternating arrangement, in the vertical direction, (N) RxGroup ×N TxGroup ) - 2 virtual array elements in D V Arranged at intervals. Near the center of the virtual receiver array, at intervals of D... H D V The more closely spaced the virtual array elements are arranged, the better the effect of reducing grating lobes and side lobes will be.

[0438] In addition, N TxGroup_ANT and N RxGroup_ANT The larger the value of N, the greater the number of virtual array elements arranged horizontally. Therefore, the aperture length of the horizontal virtual receiving array can be increased, thereby improving the horizontal angular resolution. Similarly, N... TxGroup N RxGroup The larger the aperture, the greater the number of virtual array elements arranged along the vertical direction. Therefore, the aperture length of the virtual receiving array in the vertical direction can be increased, thereby improving the angular resolution in the vertical direction.

[0439] Furthermore, a variation of basic configuration 1, example 3, can be configured as follows, that is, relative to... Figure 20 The variation 2 of the basic configuration 1 shown combines configuration methods A and B, further staggering the horizontal positions of each antenna in the transmitting and receiving antenna groups by D between the transmitting and receiving antenna groups. H .

[0440] Figure 33 N represents TxGroup =4, N TxGroup_ANT =4, N RxGroup =4, N RxGroup_ANT =4, and the horizontal positions of the antennas in the transmitting and receiving antenna groups are offset by D. HExamples of configurations for the transmitting antenna 106 and the receiving antenna 202, and an example of a configuration for a virtual receiving array. Figure 33 In equation (11), D TxGroupV =5D V D in equation (12) RxGroupH =5D H .

[0441] exist Figure 33 In the transmit antenna array, each transmit antenna in the second transmit antenna group (e.g., Tx3, Tx#7, Tx#11, Tx#15) is offset to the left by D relative to each transmit antenna in the first transmit antenna group (e.g., Tx#4, Tx#8, Tx#12, Tx#16). H Location configuration. Additionally, in Figure 33 In this configuration, the transmitting antennas (e.g., Tx2, Tx#6, Tx#10, Tx#14) of the third transmitting antenna group are respectively positioned at the same horizontal location relative to the transmitting antennas of the second transmitting antenna group. Furthermore, in... Figure 33 In the fourth transmitting antenna group, each transmitting antenna (e.g., Tx1, Tx#5, Tx#9, Tx#13) is offset to the left by D relative to each transmitting antenna in the third transmitting antenna group. H Location configuration.

[0442] In addition, Figure 33 In the receiving antenna array, the receiving antennas in the second receiving antenna group (e.g., Rx#3, Rx#7, Rx#11, Rx#15) are offset to the left by D relative to the receiving antennas in the first receiving antenna group (e.g., Rx#4, Rx#8, Rx#12, Rx#16). H Location configuration. Additionally, in Figure 33 In the third receiving antenna group, each receiving antenna (e.g., Rx#2, Rx#6, Rx#10, Rx#14) is offset to the right by a distance D relative to each receiving antenna in the second receiving antenna group. H Location configuration. Additionally, in Figure 33 In the fourth receiving antenna group, each receiving antenna (e.g., Rx#1, Rx#5, Rx#9, Rx#13) is offset to the left by D relative to each receiving antenna in the third receiving antenna group. H Location configuration.

[0443] Therefore, in addition to the effects obtained from the variation 3 of the basic configuration 1, the effects of configuration method 1-2A and configuration method 1-2B in the variation 2 of the basic configuration 1 can also be obtained.

[0444] <Basic Configuration 2>

[0445] Figure 34 Examples of configurations for the transmitting antenna 106 and receiving antenna 202 in basic configuration 2, and examples of configurations for the virtual receiving array.

[0446] (1) Configuration of transceiver antennas

[0447] exist Figure 34 In the transmitting array antenna, the number of transmitting antennas 106 is Nt = 4 (Tx#1, Tx#2, Tx#3 and Tx#4), and the number of receiving antennas 202 is Na = 4 (Rx#1, Rx#2, Rx#3 and Rx#4).

[0448] Figure 34 The transmitted array antenna shown consists of the "first transmitted antenna group" ( Figure 34 Tx#2, Tx#4) and "second transmitting antenna group" ( Figure 34 The antennas are composed of Tx#1 and Tx#3. Each transmitting antenna group contains two transmitting antenna elements, which are equidistant in the vertical direction and equidistant in the horizontal direction. Figure 34 The antenna spacing in the horizontal direction is 3D. H Additionally, the vertical direction between the "first transmitting antenna group" and the "second transmitting antenna group" ( Figure 34 The interval in the vertical direction (e.g., 3D) V .

[0449] in addition, Figure 34 The receiving array antenna shown consists of the "first receiving antenna group" ( Figure 34 Rx#2, Rx#4) and "second receiving antenna group" ( Figure 34 The antennas are composed of Rx#1 and Rx#3. Each receiving antenna group contains two receiving antenna elements, which are equidistant in the vertical direction and spaced 2D apart in the horizontal direction. H Furthermore, the vertical spacing between the "first receiving antenna group" and the "second receiving antenna group" is, for example, 2D. V .

[0450] Thus, in Figure 34 In the transmit / receive antenna configuration shown, the transmit array antenna consists of multiple transmit antenna groups, each of which, for example, contains D... H Integer multiples of the interval (in 3D) H Multiple transmitting antennas are arranged horizontally. Additionally, multiple transmitting antenna groups are arranged in 3D... V The spacing is configured in the vertical direction. In other words, the vertical antenna spacing between transmitting antenna groups (in...) Figure 34 3D V) and the horizontal antenna spacing within each transmitting antenna group (in Figure 34 3D H )same.

[0451] In addition, Figure 34 In the transceiver antenna configuration shown, the receiving array antenna consists of multiple receiving antenna groups, each of which, for example, includes D... H Integer multiples of the interval (here, 2D) H Multiple receiving antennas are arranged horizontally at intervals of 2D. Additionally, multiple receiving antenna groups are arranged in 2D... V The spacing is configured in the vertical direction. In other words, the horizontal antenna spacing within each receiving antenna group (in...) Figure 34 2D H The vertical antenna spacing between the antenna array and the receiving antenna group (in Figure 34 2D H )same.

[0452] In addition, Figure 34 In the middle, the antenna spacing in the transmitting antenna 106 (in Figure 34 3D H ) and the antenna spacing in the receiving antenna 202 (in Figure 34 2D H ( ) are different, for example, the difference is D H Additionally, in Figure 34 In the middle, multiple transmitting antenna groups are configured with 3D spacing. V (D V (intervals that are integer multiples of each other) and the spacing 2D between multiple receiving antenna groups. V (D V The difference between the intervals that are integer multiples of each other is D. V .

[0453] For example, suppose Figure 34 The horizontal direction shown corresponds to the X-axis. Figure 34 The vertical direction shown corresponds to the Y-axis direction.

[0454] exist Figure 34 In the case of the antenna configuration shown, the position coordinates of the transmitting antenna 106 constituting the transmitting array antenna are the same as the position coordinates of the transmitting antenna Tx#1 (X). T_#1 Y T_#1 Based on the reference, the position coordinates (X) of the transmitting antenna Tx#2 are represented as follows. T_#2 Y T_#2 )=(X T_#1 Y T_#1 +3D V ), the position coordinates (X) of transmitting antenna Tx#3 T_#3 Y T_#3)=(X T_#1 +3D H Y T_#1 ), the position coordinates (X) of transmitting antenna Tx#4 T_#4 Y T_#4 )=(X T_#1 +3D H Y T_#1 +3D V ).

[0455] Similarly, the position coordinates of the receiving antenna 202 constituting the receiving array antenna are the same as the position coordinates of the receiving antenna Rx#1 (X R_#1 Y R_#1 Based on the reference, the position coordinates (X) of the receiving antenna Rx#2 are represented as follows. R_#2 Y R_#2 )=(X R_#1 Y R_#1 +2D V ), the position coordinates (X) of receiving antenna Rx#3 R_#3 Y R_#3 )=(X R_#1 +2D H Y R_#1 ), the position coordinates of receiving antenna Rx#4 (X R_#4 Y R_#4 )=(X R_#1 +2D H Y R_#1 +2D V ).

[0456] (2) Configuration of the virtual receiver array

[0457] According to the above Figure 34 The configuration of the virtual receiving array (virtual antenna VA#1 to virtual antenna VA#16) formed by the transmit and receive antenna configuration shown has the following characteristics.

[0458] For example, according to Figure 34 The configuration of the transmitting array antenna and the receiving array antenna are shown, along with the position coordinates (X, Y, F) of the virtual receiving arrays VA#1 to VA#16. V_#1 Y V_#1 )~(X V_#16 Y V_#16 The details are as follows. Furthermore, VA#1 is represented here as the location reference (0, 0) of the virtual receiving array.

[0459] (0, 0), (0, 3D) V ), (3D) H ,0),(3D H 3D V (0, 2D)V (0, 5D) V ), (3D) H 2D V ), (3D) H 5D V (2D) H ,0),(2D H 3D V ), (5D H ,0), (5D H 3D V (2D) H 2D V (2D) H 5D V ), (5D H 2D V ), (5D H 5D V )

[0460] Thus, in Figure 34 In the configuration of the virtual receiver array shown, each virtual receiver array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, resulting in a narrower main lobe and thus improved angular resolution.

[0461] In addition, such as Figure 34 As shown, virtual array elements VA#4, VA#7, VA#10, and VA#13, located near the center of the virtual receiving array, are arranged horizontally at angles D. H The spacing is closely arranged, and along the vertical direction at D V The spacing is closely spaced. As an example, in... Figure 34 In the middle, the interval D H and interval D V With a value of approximately 0.5λ, the virtual array elements VA#4, VA#7, VA#10, and VA#13 are arranged horizontally at a distance of D. H =0.5λ interval configuration, and along the vertical direction with D V =0.5λ interval configuration. Therefore, compared with basic configuration 1 (for example, refer to...) Figure 8 Similarly, it can reduce the number of grid lobes.

[0462] Additionally, for example, in Figure 34 In the MIMO array configuration shown, the interval D H and interval D V With a value of approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be greater than 1λ.

[0463] Therefore, for example, it is possible to apply such as Figure 9A The antenna shown (where the antenna width W) ANT <2D H Antenna height H ANT <2D V As Figure 34 The antenna elements of at least one of the transmitting array antennas and receiving array antennas shown are as follows: Figure 9A The antenna shown uses four elements as a subarray, consisting of two planar patch antennas arranged in each direction.

[0464] exist Figure 34 In the transmission array, the horizontal antenna spacing is 3D. H The vertical antenna spacing is 3D. V .Right now, Figure 34 The antenna spacing (3D) of the transmitting array antennas shown H and 3D V The antenna spacing of the receiving array antenna is greater than 2D. H and 2D V ).in addition, Figure 34 The horizontal antenna spacing (3D) of the transmitting array antennas shown H The antenna spacing in the horizontal direction of the transmit array antennas is greater than that in Basic Configuration 1 (e.g., in...). Figure 8 2D H ).

[0465] Therefore, in Figure 34 In the transmitted array antenna shown, for example, the following antenna can be used (where the antenna width W) ANT <3D H Antenna height H ANT <3D V The longitudinal and transverse spacing ratios of this antenna are... Figure 9A The subarray of the four elements shown is larger, and as... Figure 35 The diagram shows a subarray consisting of nine elements, with three planar patch antennas arranged vertically and three planar patch antennas arranged horizontally.

[0466] Direction estimation unit 214 uses the transceiver antenna configuration described above (for example, refer to...). Figure 34 The received signal from the virtual receiving array is processed for horizontal and vertical direction estimation. For example, Figure 34 The structure of the virtual receiver array in basic configuration 2 shown is the same as that in basic configuration 1 (for example, refer to...). Figure 8 Since they are the same virtual receiver array, they can achieve the same performance.

[0467] As described above, by using Figure 34The MIMO array configuration shown allows for the configuration of horizontal and vertical antenna spacing in the virtual receiver array with an element size of approximately 1λ in the longitudinal or transverse directions, even when the antennas used as transmit and receive array antennas are approximately 0.5λ apart. This reduces grating lobes. Furthermore, for example, as... Figure 34 As shown, the virtual array elements of the virtual receiver array are configured without repetition, thus enabling the aperture length of the virtual receiver array to be increased, thereby improving the angular resolution.

[0468] Furthermore, an antenna with a subarray structure having element dimensions of at least 1λ in both the longitudinal and transverse directions can be used as the antenna element for both the transmitting antenna 106 and the receiving antenna 202. This improves the antenna's directional gain, thereby enhancing the detection performance (e.g., detection range) of the radar device 10.

[0469] Additionally, in basic configuration 2, it is possible to connect one of the transmitting array antennas and the receiving array antennas (in... Figure 34 The antenna spacing of the transmitting array antenna is set to be greater than that of the other array antenna. This allows for the application of larger subarrays within a single array antenna, thereby improving the antenna's directional gain.

[0470] <Example 1 of the variation of basic configuration 2>

[0471] In basic configuration 2 (for example, Figure 34 In the document, the case where the number of transmitting antennas 106 is set to 4 elements (Nt = 4) and the number of receiving antennas 202 is set to 4 elements (Na = 4) is described. However, the number of transmitting antennas Nt and the number of receiving antennas Na are not limited to these numbers.

[0472] In variation 1 of basic configuration 2, the transmitting array antenna is compared with basic configuration 2 (e.g., Figure 34 Similarly, for example, by a vertical spacing of 3D V The system consists of a first transmitting antenna group and a second transmitting antenna group. Furthermore, each transmitting antenna group, like the basic configuration 2, contains two transmitting antenna elements. These two transmitting antenna elements are equidistant in the vertical direction and have a horizontal antenna spacing of 3D. H .

[0473] Furthermore, in variation 1 of basic configuration 2, the receiving array antenna is similar to that in basic configuration 2, for example, with a vertical spacing of 2D. V N RxGroup One receiving antenna group (e.g., the first one) RxGroup Up to the Nth RxGroup It consists of receiving antenna groups. Additionally, each receiving antenna group contains N...RxGroup_ANT There are N receiving antenna elements. RxGroup_ANT All receiving antenna elements are positioned identically in the vertical direction, and the antenna spacing in the horizontal direction is 2D. H .

[0474] In variation 1 of basic configuration 2, the method based on N can be adopted. RxGroup and N RxGroup_ANT The configuration increases the number of antennas in the MIMO array (e.g., the number of receive antennas Na) by adjusting the value of the MIMO array.

[0475] Figure 36 N represents RxGroup =3, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 when the number of antennas is 2, and examples of configurations for a virtual receiving array.

[0476] Figure 37 N represents RxGroup =2, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 when the number of antennas is 3, and examples of configurations for a virtual receiving array.

[0477] Figure 38 N represents RxGroup =3, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 when the number of antennas is 4, and examples of configurations for virtual receiving arrays.

[0478] In addition, Figure 36 , Figure 37 and Figure 38 In, N TxGroup =2, N TxGroup_ANT =2.

[0479] exist Figure 36 , Figure 37 and Figure 38 In the various MIMO array configurations shown, for example, D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0480] Additionally, for example, in Figure 36 , Figure 37 and Figure 38 In each of the virtual receiver arrays shown, each virtual array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, thereby improving the angular resolution.

[0481] In addition, it is possible to use D H D VIntervals, closely configured in Figure 36 , Figure 37 and Figure 38 The virtual array elements shown are located near the center of each virtual receiver array. Additionally, D... H D V The number of closely spaced virtual array elements depends on N. RxGroup and N RxGroup_ANT And increase.

[0482] For example, in a virtual receiver array, in the horizontal direction, (N RxGroup_ANT ×N TxGroup_ANT ) - 2 virtual array elements in D H Alternating arrangement, in the vertical direction, (N) RxGroup ×N TxGroup_ANT ) - 2 virtual array elements in D V Arranged at intervals. Near the center of the virtual receiver array, at intervals of D... H D V The more closely spaced the virtual array elements are arranged, the better the effect of reducing grating lobes and side lobes will be.

[0483] In addition, N RxGroup_ANT The larger the value of N, the greater the number of virtual array elements arranged horizontally. Therefore, the aperture length of the horizontal virtual receiving array can be increased, thereby improving the horizontal angular resolution. Similarly, N... RxGroup The larger the aperture, the greater the number of virtual array elements arranged along the vertical direction. Therefore, the aperture length of the virtual receiving array in the vertical direction can be increased, thereby improving the angular resolution in the vertical direction.

[0484] <Example 2 of the basic configuration 2>

[0485] The following describes antenna configuration methods 2-2A and 2-2B in variation 2 of basic configuration 2.

[0486] (Configuration Method 2-2A)

[0487] In Variation 1 of Basic Configuration 2, the following situation is illustrated: by increasing the number N of the receiving antenna groups contained in the receiving array antenna... RxGroup Increase the number of virtual array elements arranged along the vertical direction. Here, as long as N... RxGroup ≥3, by increasing the number N of transmitting antenna groups in the transmitting array antenna. TxGroup It can also increase the number of virtual array elements arranged vertically in the virtual receiver array.

[0488] In this case, although the vertical antenna spacing of the transmitting antenna array can be set to a fixed value (e.g., 3D),V However, it depends on the number of receiving antenna groups N. RxGroup The virtual receiver array configuration will become a repeated configuration of the virtual array elements.

[0489] Therefore, in order to configure the virtual receiver array in a way that does not contain duplicate virtual array elements, for example, the interval D described below can be used. TxGroupV2 This refers to the even-numbered antenna spacing in the vertical direction of the transmitting antenna group.

[0490] D TxGroupV2 =D V (2N RxGroup -3) (13)

[0491] For example, in N RxGroup When D = 3, TxGroupV2 =3D V In N RxGroup When D = 4, TxGroupV2 =5D H .

[0492] For example, in the number N of transmitting antenna groups TxGroup When the value is 3, the spacing between the three transmitting antenna groups is set to {3D}. V D TxGroupV2 Additionally, regarding the number N of transmitting antenna groups... TxGroup When the number of antennas is 4, the spacing between the four transmitting antenna groups is set to {3D}. V D TxGroupV2 3D V Additionally, regarding the number N of transmitting antenna groups... RxGroup_ANT When the value is 5, the spacing between the 5 transmitting antenna groups is set to {3D}. V D TxGroupV2 3D V D TxGroupV2}

[0493] Figure 39 N represents TxGroup =4, N TxGroup_ANT =2, N RxGroup =3, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 when their numbers are equal to 2, and examples of configurations for a virtual receiving array. Figure 39 In equation (13), D TxGroupV2 =3D V .

[0494] in addition, Figure 40 N represents TxGroup =4, N TxGroup_ANT =2, N RxGroup =4, NRxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 when their numbers are equal to 2, and examples of configurations for a virtual receiving array. Figure 40 In equation (13), D TxGroupV2 =5D V .

[0495] Furthermore, unequal intervals (e.g., greater than D) may be included near the center of the virtual receiver array. H and D V In the case of the interval) configuration, D TxGroupV2 It can also be a value larger than that in equation (13).

[0496] <Configuration Method 2-2B>

[0497] In Variation 1 of Basic Configuration 2, the following situation is illustrated: by increasing the number N of receiving antennas in each receiving antenna group of the receiving array antenna... RxGroup_ANT Increase the number of virtual array elements arranged horizontally. Here, as long as N... RxGroup_ANT ≥3, by increasing the number N of transmitting antennas in the transmitting antenna group of the transmitting array antenna. TxGroup_ANT It can also increase the number of virtual array elements arranged horizontally in the virtual receiver array.

[0498] In this case, although the horizontal antenna spacing of the receiving antenna group can also be set to a fixed value (e.g., 3D), H However, this depends on the number of receiving antennas N contained in the receiving antenna group. RxGroup_ANT The virtual array configuration will become a repeated configuration of the virtual array elements.

[0499] Therefore, in order to configure the virtual receiver array without including duplicate virtual array elements, for example, the interval described below can be used as the even-numbered antenna interval in the horizontal antenna interval of the transmit antennas contained in the transmit antenna group.

[0500] D TxAntH =D H (2N RxGroup_ANT -3) (14)

[0501] For example, in N RxGroup_ANT When D = 3, TxAntH =3D H In N RxGroup_ANT When D = 4, TxAntH =5D H .

[0502] For example, in the number N of transmitting antennas contained in the transmitting antenna group TxGroup_ANTWhen the number of antennas is 3, the antenna spacing of the three transmitting antennas is set to {3D}. H D TxAntH Additionally, regarding the number of transmitting antennas N... TxGroup_ANT When the number of antennas is 4, the antenna spacing of the four transmitting antennas is set to {3D}. H D TxAntH 3D H Similarly, with N transmitting antennas... TxGroup_ANT When the number of antennas is 5, the antenna spacing of the 5 transmitting antennas is set to {3D}. H D TxAntH 3D H D TxAntH}

[0503] Figure 41 N represents TxGroup =2, N TxGroup_ANT =4, N RxGroup =2, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 when the number of antennas is 3, and examples of configurations for a virtual receiving array. Figure 41 In equation (14), D TxAntH =3D H .

[0504] Figure 42 N represents TxGroup =2, N TxGroup_ANT =4, N RxGroup =2, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 when the number of antennas is 4, and examples of configurations for a virtual receiving array. Figure 41 In equation (14), D TxAntH =5D H .

[0505] Furthermore, unequal intervals (e.g., greater than D) may be included near the center of the virtual receiver array. H and D V In the case of the interval) configuration, D TxAntH It can also be a value larger than that in equation (14).

[0506] The above describes configuration method 2-2A and configuration method 2-2B in variant example 2 of basic configuration 2.

[0507] For example, in Figures 39-42 In the transmit / receive antenna configuration shown (e.g., MIMO array configuration), D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0508] Additionally, for example, in Figures 39-42 In each of the virtual receiver arrays shown, each virtual array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, thereby improving the angular resolution.

[0509] Additionally, for example, it is possible to use D H D V Intervals, closely configured in Figures 39-42 The virtual array elements shown are located near the center of the virtual receiver array. Additionally, D... H D V The number of closely spaced virtual array elements depends on N. TxGroup N TxGroup_ANT N RxGroup and N RxGroup_ANT And increase.

[0510] For example, in a virtual receiver array, in the horizontal direction, (N RxGroup_ANT ×N TxGroup_ANT ) - 2 virtual array elements in D H Alternating arrangement, in the vertical direction, (N) RxGroup ×N TxGroup ) - 2 virtual array elements in D V Arranged at intervals. Near the center of the virtual receiver array, at intervals of D... H D V The more closely spaced virtual array elements are added, the better the effect of reducing grating lobes and side lobes can be.

[0511] In addition, N TxGroup_ANT N RxGroup_ANT The larger the value of N, the greater the number of virtual array elements arranged horizontally. Therefore, the aperture length of the horizontal virtual receiving array can be increased, thereby improving the horizontal angular resolution. Similarly, N... TxGroup N RxGroup The larger the aperture, the greater the number of virtual array elements arranged along the vertical direction. Therefore, the aperture length of the virtual receiving array in the vertical direction can be increased, thereby improving the angular resolution in the vertical direction.

[0512] Furthermore, in variation 2 of basic configuration 2, a configuration combining configuration method 2-2A and configuration method 2-2B can also be used. Figure 43 N represents TxGroup =4, N TxGroup_ANT =4, N RxGroup =4, N RxGroup_ANT Examples of configurations for transmitting antenna 106 and receiving antenna 202 with a configuration of 4 antennas, and examples of configurations for a virtual receiving array. Figure 43In equation (13), D TxGroupV2 =5D H D in equation (14) TxAntH =5D H Therefore, the combined effect of configuration method 2-2A and configuration method 2-2B can be obtained.

[0513] <Example 3 of the variation of basic configuration 2>

[0514] The following describes antenna configuration methods 2-3A, 2-3B, and 2-3C in variation 3 of basic configuration 2.

[0515] (Configuration method 2-3A)

[0516] Basic Configuration 2 describes a configuration where the horizontal positions of the transmitting antennas in each transmitting antenna group are identical. However, this is not a limitation; the horizontal configuration of the transmitting antennas in each transmitting antenna group can also differ.

[0517] For example, in a transmitting array antenna, the horizontal positions can be offset (in other words, shifted). H The first and second transmitting antenna groups are configured with their respective transmitting antennas.

[0518] offset along the horizontal direction D H The direction is relative to each transmitting antenna in the first transmitting antenna group, or it can be any direction to the right or left of each transmitting antenna in the second transmitting antenna group.

[0519] Figure 44 This indicates that the transmit antennas (e.g., Tx#1, Tx#3) in the second transmit antenna group of the transmit array are offset to the right by D relative to the transmit antennas (e.g., Tx#2, Tx#4) in the first transmit antenna group. H Examples of configurations for transmitting antenna 106 and receiving antenna 202, and examples of configurations for virtual receiving arrays.

[0520] exist Figure 44 In the middle, the horizontal positions of Tx#1 and Tx#2 differ by D. H Additionally, the horizontal positions of Tx#3 and Tx#4 differ by D. H .

[0521] (Configuration method 2-3B)

[0522] Basic Configuration 2 describes a configuration where the horizontal positions of the receiving antennas in each receiving antenna group are identical. However, this is not a limitation; the horizontal configuration of the receiving antennas in each receiving antenna group can also differ.

[0523] For example, in a receiving array antenna, the horizontal positions can be offset by D. H The first receiving antenna group and the second receiving antenna group are configured with their respective receiving antennas.

[0524] offset along the horizontal direction D H The direction is relative to each receiving antenna in the first receiving antenna group, or it can be any direction to the right or left of each receiving antenna in the second receiving antenna group.

[0525] Figure 45 This indicates that the receiving antennas (e.g., Rx#1, Rx#3) in the second receiving antenna group of the receiving antenna array are offset to the left relative to the receiving antennas (e.g., Rx#2, Rx#4) in the first receiving antenna group. H Examples of configurations for transmitting antenna 106 and receiving antenna 202, and examples of configurations for virtual receiving arrays.

[0526] exist Figure 45 In the middle, the horizontal positions of Rx#1 and Rx#2 differ by D. H Additionally, the horizontal positions of Rx#3 and Rx#4 differ by D. H .

[0527] (Configuration method 2-3C)

[0528] Configuration method 2-3C is a combination of configuration method 2-3A and configuration method 2-3B.

[0529] For example, in a transmit array antenna, the horizontal positions of the first transmit antenna group and the second transmit antenna group are offset by D. H The transmitting antenna is configured accordingly. Similarly, the horizontal positions of the first receiving antenna group and the second receiving antenna group in the receiving array are offset by D. H Configure the receiving antenna on the ground.

[0530] In addition, D is offset horizontally. H The direction can be, for example, relative to the transmitting antennas in the first transmitting antenna group, or any direction to the right or left of the transmitting antennas in the second transmitting antenna group. Additionally, it can be offset by D along the horizontal direction. HThe direction can be any direction relative to the receiving antennas in the first receiving antenna group, or to the right or left of the receiving antennas in the second receiving antenna group.

[0531] Figure 46 Examples of configurations for the transmitting antenna 106 and receiving antenna 202 in configuration methods 2-3C, and an example of a configuration for a virtual receiving array. Figure 46 In the transmit array antenna, each transmit antenna (e.g., Tx#1, Tx#3) in the second transmit antenna group is offset to the right by D relative to each transmit antenna (e.g., Tx#2, Tx#4) in the first transmit antenna group. H Location configuration. Additionally, in Figure 46 In the receiving array antenna, each receiving antenna (e.g., Rx#1, Rx#3) in the second receiving antenna group is offset to the right by D relative to each receiving antenna (e.g., Rx#2, Rx#4) in the first receiving antenna group. H Location configuration.

[0532] Figure 47 Examples of configurations for the transmitting antenna 106 and receiving antenna 202 in configuration methods 2-3C, and an example of a configuration for a virtual receiving array. Figure 47 In the transmit array antenna, each transmit antenna (e.g., Tx#1, Tx#3) in the second transmit antenna group is offset to the right by D relative to each transmit antenna (e.g., Tx#2, Tx#4) in the first transmit antenna group. H Location configuration. Additionally, in Figure 47 In the receiving antenna array, each receiving antenna in the second receiving antenna group (e.g., Rx#1, Rx#3) is offset to the left by D relative to each receiving antenna in the first receiving antenna group (e.g., Rx#2, Rx#4). H Location configuration.

[0533] For example, in the receiving antenna group and the transmitting antenna group, the antennas will be offset by D along the horizontal direction. H The direction is set to different directional configurations (e.g., Figure 47 In contrast, in the receiving antenna group and the transmitting antenna group, the horizontal offset D is... H Configurations with the same orientation (e.g., Figure 46 It will configure the virtual receiver array elements more closely near the center of the virtual receiver array configuration, which is therefore more appropriate.

[0534] The above describes configuration methods 2-3A to 2-3C.

[0535] For example, in Figures 45-47 In the transmit / receive antenna configuration shown (e.g., MIMO array configuration), DH and D V The value is set to approximately 0.5λ. Therefore, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 are designed to be approximately 1λ.

[0536] Therefore, in variation 3 of basic configuration 1, for example, it is possible to apply... Figure 9A The antenna shown uses four elements arranged in a planar patch antenna with two elements arranged in a horizontal and vertical direction to form a sub-array (where the antenna width W). ANT <2D H Antenna height H ANT <2D V (Not shown).

[0537] In addition, Figures 45-47 In the transmitted array antenna shown, for example, the following antenna can be used (where the antenna width W) ANT <3D H Antenna height H ANT <3D V The longitudinal and transverse spacing ratios of this antenna are... Figure 9A The subarray shown has four elements, which is larger, and uses nine elements as a subarray, consisting of three planar patch antennas arranged vertically and three planar patch antennas arranged horizontally.

[0538] Furthermore, in variation 3 of basic configuration 2, for at least one of the transmit array antennas and receive array antennas, the horizontal positions of the transmit antennas in each transmit antenna group or the receive antennas in each receive antenna group are different from each other. Therefore, in variation 3 of basic configuration 2, as long as the horizontal direction W of the subarray is different... ANT The component size is smaller than D H Then the element size in the longitudinal direction of the subarray can be any size. For example, in Figures 45-47 In each of the transmitting array antennas, it can also be used Figure 25A The subarray shown consists of a planar patch antenna with eight elements arranged vertically and a planar patch antenna with one element arranged horizontally.

[0539] (A combination of Modification 3 and Modification 1 or Modification 2)

[0540] Furthermore, the modified example 3 of the basic configuration 2 can also be combined with the modified example 1 or the modified example 2 of the basic configuration 2.

[0541] For example, it can be configured such that, relative to the configuration of the transmit array antenna in variant 1 or variant 2 of basic configuration 2, the horizontal positions of each transmit antenna in the transmit antenna group are further offset by D. H .

[0542] Similarly, for example, it can be configured such that, relative to the configuration of the receiving array antenna in variant 1 or variant 2 of basic configuration 2, the horizontal positions of each receiving antenna in the receiving antenna group are further offset by D. H .

[0543] Figure 48 , Figure 49 , Figure 50A , Figure 50B , Figure 51A and Figure 51B This illustrates an example of the antenna configuration in a combination of Modification 3 and Modification 2.

[0544] Figure 48 N represents TxGroup =4, N TxGroup_ANT =4, N RxGroup =4, N RxGroup_ANT =4, and the horizontal positions of the antennas in the transmitting antenna group are offset by D. H Examples of configurations for the transmitting antenna 106 and the receiving antenna 202, and an example of a configuration for a virtual receiving array. Figure 48 In equation (13), D TxGroupV2 =5D H D in equation (14) TxAntH =5D H .

[0545] Figure 49 N represents TxGroup =4, N TxGroup_ANT =4, N RxGroup =4, N RxGroup_ANT =4, and the horizontal positions of the antennas in the receiving antenna group are offset by D. H Examples of configurations for the transmitting antenna 106 and the receiving antenna 202, and an example of a configuration for a virtual receiving array. Figure 49 In equation (13), D TxGroupV2 =5D H D in equation (14) TxAntH =5D H .

[0546] exist Figure 49 In the receiving antenna array, each receiving antenna in the second receiving antenna group (e.g., Rx3, Rx#7, Rx#11, Rx#15) is offset to the left by D relative to each receiving antenna in the first receiving antenna group (e.g., Rx#4, Rx#8, Rx#12, Rx#16). H Location configuration. Additionally, in Figure 49In the third receiving antenna group, each receiving antenna (e.g., Rx2, Rx#6, Rx#10, Rx#14) is offset to the right by D relative to each receiving antenna in the second receiving antenna group. H Location configuration. Additionally, in Figure 49 In the fourth receiving antenna group, each receiving antenna (e.g., Rx1, Rx#5, Rx#9, Rx#13) is offset to the left by D relative to each receiving antenna in the third receiving antenna group. H Location configuration.

[0547] Figure 50A N represents TxGroup =4, N TxGroup_ANT =4, N RxGroup =4, N RxGroup_ANT =4, and the horizontal positions of the antennas in the transmitting and receiving antenna groups are offset by D. H Example of the configuration of transmitting antenna 106 and receiving antenna 202 under the following conditions: Figure 50B This represents a configuration example of a virtual receiver array. Figure 50A In equation (13), D TxGroupV2 =5D H D in equation (14) TxAntH =5D H .

[0548] exist Figure 50A In the transmit antenna array, each transmit antenna in the second transmit antenna group (e.g., Tx3, Tx#7, Tx#11, Tx#15) is offset to the left by D relative to each transmit antenna in the first transmit antenna group (e.g., Tx#4, Tx#8, Tx#12, Tx#16). H Location configuration. Additionally, in Figure 50A In the third transmitting antenna group, each transmitting antenna (e.g., Tx2, Tx#6, Tx#10, Tx#14) is offset to the left by D relative to each transmitting antenna in the second transmitting antenna group. H Location configuration. Additionally, in Figure 50A In the fourth transmitting antenna group, each transmitting antenna (e.g., Tx1, Tx#5, Tx#9, Tx#13) is offset to the left by D relative to each transmitting antenna in the third transmitting antenna group. H Location configuration.

[0549] In addition, Figure 50A In the receiving antenna array, the receiving antennas in the second receiving antenna group (e.g., Rx#3, Rx#7, Rx#11, Rx#15) are offset to the right by D relative to the receiving antennas in the first receiving antenna group (e.g., Rx#4, Rx#8, Rx#12, Rx#16).H Location configuration. Additionally, in Figure 50A In the third receiving antenna group, each receiving antenna (e.g., Rx#2, Rx#6, Rx#10, Rx#14) is offset to the right by a distance D relative to each receiving antenna in the second receiving antenna group. H Location configuration. Additionally, in Figure 50A In the fourth receiving antenna group, each receiving antenna (e.g., Rx#1, Rx#5, Rx#9, Rx#13) is offset to the right by D relative to each receiving antenna in the third receiving antenna group. H Location configuration.

[0550] Figure 51A N represents TxGroup =4, N TxGroup_ANT =4, N RxGroup =4, N RxGroup_ANT =4, and the horizontal positions of the antennas in the transmitting and receiving antenna groups are offset by D. H Example of the configuration of transmitting antenna 106 and receiving antenna 202 under the following conditions: Figure 51B This represents a configuration example of a virtual receiver array. Figure 50A In equation (13), D TxGroupV2 =5D H D in equation (14) TxAntH =5D H .

[0551] exist Figure 51A In the transmit antenna array, each transmit antenna in the second transmit antenna group (e.g., Tx3, Tx#7, Tx#11, Tx#15) is offset to the left by D relative to each transmit antenna in the first transmit antenna group (e.g., Tx#4, Tx#8, Tx#12, Tx#16). H Location configuration. Additionally, in Figure 51A In the third transmitting antenna group, each transmitting antenna (e.g., Tx2, Tx#6, Tx#10, Tx#14) is offset to the right by a distance D relative to each transmitting antenna in the first transmitting antenna group. H Location configuration. Additionally, in Figure 51A In the fourth transmitting antenna group, each transmitting antenna (e.g., Tx1, Tx#5, Tx#9, Tx#13) is offset to the left by D relative to each transmitting antenna in the third transmitting antenna group. H Location configuration.

[0552] In addition, Figure 51AIn the receiving antenna array, the receiving antennas in the second receiving antenna group (e.g., Rx#3, Rx#7, Rx#11, Rx#15) are offset to the left by D relative to the receiving antennas in the first receiving antenna group (e.g., Rx#4, Rx#8, Rx#12, Rx#16). H Location configuration. Additionally, in Figure 51A In the third receiving antenna group, each receiving antenna (e.g., Rx#2, Rx#6, Rx#10, Rx#14) is offset to the right by a distance D relative to each receiving antenna in the second receiving antenna group. H Location configuration. Additionally, in Figure 51A In the fourth receiving antenna group, each receiving antenna (e.g., Rx#1, Rx#5, Rx#9, Rx#13) is offset to the left by D relative to each receiving antenna in the third receiving antenna group. H Location configuration.

[0553] For example, in Figure 48 , Figure 49 , Figure 50A and Figure 51A In each MIMO array configuration shown, D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be 1λ or larger.

[0554] Additionally, for example, in Figure 48 , Figure 49 , Figure 50B and Figure 51B In each of the virtual receiver arrays shown, each virtual array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, thereby improving the angular resolution.

[0555] Furthermore, regarding the number N of transmitting antenna groups TxGroup When the number is 3 or more, the horizontal positions of the transmitting antennas in each transmitting antenna group can be staggered in a fixed direction (right or left), or the direction in which the horizontal positions of the transmitting antennas in each transmitting antenna group are staggered to the right or left can be changed according to the transmitting antenna group. Similarly, when the number of receiving antenna groups N RxGroup When the number is 3 or higher, the horizontal positions of the receiving antennas in each receiving antenna group can be staggered in a fixed direction (right or left). Alternatively, the direction in which the horizontal positions of the receiving antennas in each receiving antenna group are staggered to the right or left can be changed according to the receiving antenna group.

[0556] In any antenna configuration, it is possible to achieve DH D V The virtual array elements are spaced out and closely arranged near the center of the virtual receiver array. Additionally, with D... H D V The number of closely spaced virtual array elements will, for example, depend on N. TxGroup N TxGroup_ANT N RxGroup and N RxGroup_ANT And increase.

[0557] For example, in the horizontal direction, (N) TxGroup_ANT ×N RxGroup_ANT ) - 2 virtual array elements in D H Alternating arrangement, in the vertical direction, (N) RxGroup ×N TxGroup ) - 2 virtual array elements in D V Arranged at intervals. Near the center of the virtual receiver array, at intervals of D... H D V The more closely spaced virtual array elements are added, the better the effect of reducing grating lobes and side lobes can be.

[0558] In addition, N TxGroup_ANT and N RxGroup_ANT The larger the value of N, the greater the number of virtual array elements arranged horizontally. Therefore, the aperture length of the horizontal virtual receiving array can be increased, thereby improving the horizontal angular resolution. Similarly, N... TxGroup N RxGroup The larger the aperture, the greater the number of virtual array elements arranged along the vertical direction. Therefore, the aperture length of the virtual receiving array in the vertical direction can be increased, thereby improving the angular resolution in the vertical direction.

[0559] <Basic Configuration 3>

[0560] Figures 52A-52D Examples of configurations for the transmitting antenna 106 and receiving antenna 202 in basic configuration 3, and examples of configurations for the virtual receiving array.

[0561] (1) Configuration of transceiver antennas

[0562] exist Figures 52A-52D In the transmitting array antenna, the number of transmitting antennas 106 is Nt = 4 (Tx#1, Tx#2, Tx#3 and Tx#4), and the number of receiving antennas 202 is Na = 4 (Rx#1, Rx#2, Rx#3 and Rx#4).

[0563] Figures 52A-52D The transmitted array antenna shown consists of the "first transmitted antenna group" ( Figures 52A-52DTx#2, Tx#4) and "second transmitting antenna group" ( Figures 52A-52D The antennas are composed of Tx#1 and Tx#3. Each transmitting antenna group contains two transmitting antenna elements, which are equidistant in the vertical direction and equidistant in the horizontal direction. Figures 52A-52D The antenna spacing in the horizontal direction is 2D. H Additionally, the vertical direction between the "first transmitting antenna group" and the "second transmitting antenna group" ( Figures 52A-52D The interval in the vertical direction is, for example, 2D. V .

[0564] In addition, Figures 52A-52D In the diagram, the horizontal positions of the transmitting antennas in the first and second transmitting antenna groups are offset by D. H The different positions of each other. For example, the horizontal positions of the transmitting antennas in the second transmitting antenna group are offset by +D from the horizontal positions of the transmitting antennas in the first transmitting antenna group. H The configuration may be misaligned -D H Configuration.

[0565] in addition, Figures 52A-52D The receiving array antenna shown consists of the "first receiving antenna group" ( Figures 52A-52D Rx#1, Rx#2) and "second receiving antenna group" ( Figures 52A-52D The antennas are composed of Rx#3 and Rx#4. Each receiving antenna group contains two receiving antenna elements, which are equidistant in the horizontal direction and spaced 2D apart in the vertical direction. V Furthermore, the horizontal spacing between the "first receiving antenna group" and the "second receiving antenna group" is, for example, 2D. H .

[0566] In addition, Figures 52A-52D In the diagram, the vertical positions of the receiving antennas in the first and second receiving antenna groups are offset by D. V The antennas are positioned differently from each other. For example, the vertical positions of the antennas in the second receiving antenna group are offset by +D from the vertical positions of the antennas in the first receiving antenna group. V The configuration may be misaligned -D V Configuration.

[0567] For example, in Figure 52A and Figure 52C In the transceiver antenna configuration shown, the respective positions of the transmitting antennas in the transmitting array antenna and the respective positions of the receiving antennas in the receiving array antenna are in the following relationship: in a two-dimensional plane composed of the horizontal and vertical directions, for example, rotated by +90° or -90°.

[0568] In addition, Figure 52B and Figure 52D In the transceiver antenna configuration shown, the respective positions of the transmitting antennas in the transmitting array antenna and the respective positions of the receiving antennas in the receiving array antenna are in the following relationship: in a two-dimensional plane composed of the horizontal and vertical directions, for example, rotated by +90° or -90° and reversed.

[0569] Furthermore, the horizontal offset ΔH between the second transmitting antenna group and the first transmitting antenna group Tx The two combinations (+D) H -D H The offset ΔV of the second receiving antenna group relative to the first receiving antenna group in the vertical direction. Rx The two combinations (+D) V -D V () can also be any combination. Here, for example, in Figures 52A-52D In the middle, +D H Set the direction to the right, -D H Set it to the left direction. Additionally, in Figures 52A-52D In the middle, +D V Set the direction to up, -D V Set it to the downward direction.

[0570] For example, it could also be one of four combined structures (ΔH) Tx ΔV Rx )=(+D H +D V ), (+D H -D V ), (-D H +D V ), (D H -D V Any combination of ) . As an example, Figures 52A-52D They represent (ΔH) Tx ΔV Rx )=(-D H -D V ), (-D H +D V ), (+D H +D V ), (+D H -D V MIMO array configuration and virtual receiver array configuration under the following conditions.

[0571] according to Figures 52A-52DThe virtual receiver array configuration obtained by the MIMO array configuration with the antenna group offset shown becomes a rotationally symmetric configuration, thereby obtaining the same angle measurement performance.

[0572] For example, suppose Figure 52A The horizontal direction shown corresponds to the X-axis. Figure 52A The vertical direction shown corresponds to the Y-axis direction.

[0573] For example, in Figure 52A In the case of the antenna configuration shown, the position coordinates of the transmitting antenna 106 constituting the transmitting array antenna are the same as the position coordinates of the transmitting antenna Tx#1 (X). T_#1 Y T_#1 Based on the reference, the position coordinates (X) of the transmitting antenna Tx#2 are represented as follows. T_#2 Y T_#2 )=(X T_#1 +D H Y T_#1 +2D V ), the position coordinates (X) of transmitting antenna Tx#3 T_#3 Y T_#3 )=(X T_#1 +2D H Y T_#1 ), the position coordinates (X) of transmitting antenna Tx#4 T_#4 Y T_#4 )=(X T_#1 +3D H Y T_#1 +2D V ).

[0574] Similarly, the position coordinates of the receiving antenna 202 constituting the receiving array antenna are the same as the position coordinates of the receiving antenna Rx#1 (X R_#1 Y R_#1 Based on the reference, the position coordinates (X) of the receiving antenna Rx#2 are represented as follows. R_#2 Y R_#2 )=(X R_#1 Y R_#1 +2D V ), the position coordinates (X) of receiving antenna Rx#3 R_#3 Y R_#3 )=(X R_#1 +2D H Y R_#1 -D V ), the position coordinates of receiving antenna Rx#4 (X R_#4 Y R_#4 )=(X R_#1 +2D H Y R_#1 +DV ).

[0575] (2) Configuration of the virtual receiver array

[0576] According to the above Figures 52A-52D The configuration of the virtual receiving array (virtual antenna VA#1 to virtual antenna VA#16) formed by the transmit and receive antenna configuration shown has the following characteristics.

[0577] For example, according to Figure 52A The configuration of the transmitting array antenna and the receiving array antenna are shown, along with the position coordinates (X, Y, F) of the virtual receiving arrays VA#1 to VA#16. V_#1 Y V_#1 )~(X V_#16 Y V_#16 The details are as follows. Furthermore, VA#1 is represented here as the location reference (0, 0) of the virtual receiving array.

[0578] (0, 0), (D) H 2D V (2D) H ,0),(3D H 2D V (0, 2D) V ), (D H 4D V (2D) H 2D V ), (3D) H 4 V (2D) H -D V ), (3D) H D V (4D) H -D V ), (5D H D V (2D) H D V ), (3D) H 3D V (4D) H D V ), (5D H 3D V )

[0579] Thus, in Figures 52A-52D In the configuration of the virtual receiver array shown, each virtual receiver array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, resulting in a narrower main lobe and thus improved angular resolution.

[0580] Additionally, located Figures 52A-52D The virtual array elements VA#4, VA#7, VA#10, and VA#13 near the center of the virtual receiver array shown are arranged horizontally at D... H The spacing is closely arranged, and along the vertical direction at D V The spacing is closely spaced. As an example, in... Figures 52A-52D In the middle, the interval D H and interval D V With a value of approximately 0.5λ, the virtual array elements located near the center of the virtual receiver array move horizontally along the direction of D. H =0.5λ interval configuration, and along the vertical direction with D V =0.5λ interval configuration. Therefore, compared with basic configuration 1 (for example, refer to...) Figure 8 Similarly, it can reduce the number of grid lobes.

[0581] Additionally, for example, in Figures 52A-52D In the MIMO array configuration shown, the interval D H and interval D V With a value of approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be greater than 1λ.

[0582] Therefore, for example, it is possible to apply such as Figure 9A The antenna shown (where the antenna width W) ANT <2D H Antenna height H ANT <2D V As Figures 52A-52D Each antenna of at least one of the transmitting array antennas and receiving array antennas shown, as described... Figure 9A The antenna shown uses four elements as a subarray, consisting of two planar patch antennas arranged in each direction.

[0583] Furthermore, the number of transmitting antennas contained in the first transmitting antenna group (hereinafter referred to as "N") TxHGroup1_ANT The number of transmitting antennas in the second transmitting antenna group (hereinafter referred to as "N") and the number of transmitting antennas in the second transmitting antenna group (hereinafter referred to as "N") TxHGroup2_ANT The numbers can be the same or differ by one antenna. For example, |N TxHGroup1_ANT -N TxHGroup2_ANT | = 0 or 1.

[0584] Similarly, the number of receiving antennas contained in the first receiving antenna group (hereinafter referred to as "N") RxVGroup1_ANT The number of receiving antennas in the second receiving antenna group (hereinafter referred to as "N") and the number of receiving antennas in the second receiving antenna group (hereinafter referred to as "N") RxVGroup2_ANT The numbers can be the same or differ by one antenna. For example, |N RxVGroup1_ANT -NRxVGroup2_ANT | = 0 or 1.

[0585] Figures 53A-53D The following structural example illustrates the number of transmitting antennas N contained in the first transmitting antenna group. TxHGroup1_ANT The number of transmitting antennas N contained in the second transmitting antenna group TxHGroup2_ANT The first receiving antenna group contains N receiving antennas, which differ by one antenna. RxVGroup1_ANT The sum and the number N of receiving antennas contained in the second receiving antenna group RxVGroup2_ANT This minimizes the number of antennas required for a MIMO array with the same number of antennas.

[0586] like Figures 53A-53D As shown, |N TxHGroup1_ANT -N TxHGroup2_ANT |=1 and|N RxVGroup1_ANT -N RxVGroup2_ANT The MIMO array with the minimum number of antennas when |=0 is the one with 3 transmitting antennas and 4 receiving antennas (N RxVGroup1_ANT =N RxVGroup2_ANT =2) structure, for example, exists Figures 53A-53D The four modes.

[0587] Figure 53A N represents TxHGroup1_ANT =1(Tx#2), N TxHGroup2_ANT =2(Tx#1, Tx#3), (ΔH) Tx ΔV Rx )=(-D H -D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0588] Figure 53B N represents TxHGroup1_ANT =1(Tx#2), N TxHGroup2_ANT =2(Tx#1, Tx#3), (ΔH) Tx ΔV Rx )=(-D H +D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0589] Figure 53C Indicates NT xHGroup1_ANT =2(Tx#2, Tx#3), N TxHGroup2_ANT =1(Tx#1),(ΔH) Tx ΔV Rx )=(+D H -D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0590] Figure 53D N represents TxHGroup1_ANT =2(Tx#2, Tx#3), N TxHGroup2_ANT =1(Tx#1),(ΔH) Tx ΔV Rx )=(+D H +D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0591] Figures 54A to 54D The following structural example illustrates the number of transmitting antennas N contained in the first transmitting antenna group. TxHGroup1_ANT The number of transmitting antennas N contained in the second transmitting antenna group TxHGroup2_ANT The number of receiving antennas N is the same, and the first receiving antenna group contains the same number of receiving antennas. RxVGroup1_ANT The number of receiving antennas N contained in the second receiving antenna group RxVGroup2_ANT The MIMO array has the minimum number of antennas when there is a difference of one antenna.

[0592] like Figures 54A to 54D As shown, |N TxHGroup1_ANT -N TxHGroup2_ANT |=0 and|N RxVGroup1_ANT -N RxVGroup2_ANT The MIMO array with the minimum number of antennas when |=1 is the one with 4 (N) transmit antennas. TxVGroup1_ANT =N TxVGroup2_ANT =2), a structure with 3 receiving antennas, for example, there exists Figures 54A to 54D The four modes.

[0593] Figure 54A N represents RxHGroup1_ANT =1(Rx#1), ​​N RxHGroup2_ANT =2(Rx#2, Rx#3), (ΔH) Tx ΔV Rx )=(-D H +D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0594] Figure 54B N represents RxHGroup1_ANT =1(Rx#1), ​​N RxHGroup2_ANT =2(Rx#2, Rx#3), (ΔH) Tx ΔV Rx )=(+D H +D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0595] Figure 54C N representsRxHGroup1_ANT =2(Rx#1, Rx#2), N RxHGroup2_ANT =1(Rx#3), (ΔH) Tx ΔV Rx )=(-D H -D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0596] Figure 54D N represents RxHGroup1_ANT =2(Rx#1, Rx#2), N RxHGroup2_ANT =1(Rx#3), (ΔH) Tx ΔV Rx )=(+D H -D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0597] Figures 55A to 55D The following structural example illustrates the number of transmitting antennas N contained in the first transmitting antenna group. TxHGroup1_ANT The number of transmitting antennas N contained in the second transmitting antenna group TxHGroup2_ANT The first receiving antenna group contains N receiving antennas, which differ by one antenna. RxVGroup1_ANT The number of receiving antennas N contained in the second receiving antenna group RxVGroup2_ANT The MIMO array has the minimum number of antennas when there is a difference of one antenna.

[0598] like Figures 55A to 55D As shown, |N TxHGroup1_ANT -N TxHGroup2_ANT |=1 and|N RxVGroup1_ANT -N RxVGroup2_ANT The MIMO array with the minimum number of antennas when |=1 is a structure with 3 transmit antennas and 3 receive antennas. For example, there exists Figures 55A to 55D The four modes.

[0599] Figure 55A N represents TxVGroup1_ANT =1(Tx#2), N TxVGroup2_ANT =2(Tx#1, Tx#3), N RxHGroup1_ANT =2(Rx#1, Rx#2), N RxHGroup2_ANT =1(Rx#3), (ΔH) Tx ΔV Rx )=(-D H -D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0600] Figure 55B N represents TxVGroup1_ANT=1(Tx#2), N TxVGroup2_ANT =2(Tx#1, Tx#3), N RxHGroup1_ANT =1(Rx#1), ​​N RxHGroup2_ANT =2(Rx#2, Rx#3), (ΔH) Tx ΔV Rx )=(-D H +D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0601] Figure 55C N represents TxVGroup1_ANT =2(Tx#2, Tx#3), N TxVGroup2_ANT =1(Tx#1), ​​N RxHGroup1_ANT =2(Rx#1, Rx#2), N RxHGroup2_ANT =1(Rx#3), (ΔH) Tx ΔV Rx )=(+D H -D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0602] Figure 55D N represents TxVGroup1_ANT =2(Tx#2, Tx#3), N TxVGroup2_ANT =1(Tx#1), ​​N RxHGroup1_ANT =1(Rx#1), ​​N RxHGroup2_ANT =2(Rx#2, Rx#3), (ΔH) Tx ΔV Rx )=(+D H +D V Examples of MIMO array configuration and virtual receiver array configuration under the following conditions:

[0603] For example, in Figures 55A to 55D In this configuration, the transmitting array antenna contains three transmitting antennas, and the receiving array antenna contains three receiving antennas.

[0604] Additionally, two of the three transmitting antennas (e.g., the transmitting antennas contained in a transmitting antenna group) are, for example, horizontally spaced 2D apart. H (In other words, D) H The antennas are configured with a spacing of twice the distance between them. Additionally, the remaining transmitting antenna of the three transmitting antennas is, for example, spaced D horizontally from each of the aforementioned two transmitting antennas. H The antennas are configured in an interleaved manner (in other words, positioned in the middle), with a vertical spacing of 2D from each of the two transmitting antennas mentioned above. V Interval (in other words, D) VConfigured in a way that is twice the interval.

[0605] Similarly, two of the three receiving antennas (e.g., the receiving antennas in a receiving antenna group) are, for example, spaced 2D apart in the vertical direction. V (In other words, D) V The antennas are arranged at twice the spacing of the two previously mentioned antennas. Additionally, the remaining antenna of the three receiving antennas is, for example, spaced D apart from each of the two previously mentioned receiving antennas in the vertical direction. V The antennas are configured in an interleaved manner (in other words, positioned in the middle), with a horizontal spacing of 2D from each of the two receiving antennas mentioned above. H Interval (in other words, D) H Configured in a way that is twice the interval.

[0606] In other words, in Figures 55A to 55D In this configuration, the respective positions of the three transmitting antennas and the three receiving antennas are related in that they are rotationally symmetrical within a two-dimensional plane defined by the horizontal direction (e.g., the X-axis) and the vertical direction (e.g., the Y-axis). For example, in... Figures 52A-52D In this configuration, the transmitting array antenna and the receiving array antenna are rotated by ±90 degrees.

[0607] Furthermore, in the transmit and receive antenna configurations of basic configuration 3 and its various variations, at least one antenna configuration with the aforementioned configuration relationship of 3 transmit antennas or 3 receive antennas is included.

[0608] Figures 52A-52D , Figures 53A-53D , Figures 54A to 54D and Figures 55A to 55D The virtual array elements of the virtual receiver array shown are arranged in different positions without repetition. Therefore, the aperture length of the virtual receiver array can be increased, thereby improving the angular resolution.

[0609] Additionally, the virtual array elements located near the center of the virtual receiver array are in D H D V The spacing is closely spaced. As an example, in... Figures 52A-52D , Figures 53A-53D , Figures 54A to 54D and Figures 55A to 55D In the middle, the interval D H and interval D V With a value of approximately 0.5λ, the virtual array elements located near the center of the virtual receiver array move horizontally along the direction of D. H =0.5λ interval configuration, and along the vertical direction with D V A spacing configuration of 0.5λ is used. This reduces the number of grid lobes.

[0610] Additionally, for example, in the MIMO array configuration of basic configuration 3, the interval D is... H and interval D V With a value of approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0611] Therefore, for example, it is possible to apply such as Figure 9A The antenna shown (where the antenna width W) ANT <2D H Antenna height H ANT <2D V As Figures 52A-52D , Figures 53A-53D , Figures 54A to 54D and Figures 55A to 55D The antenna elements of at least one of the transmitting array antennas and receiving array antennas shown are as follows: Figure 9A The antenna shown uses four elements as a subarray, consisting of two planar patch antennas arranged in each direction.

[0612] Additionally, in the case of transmitting antenna 106, as long as the horizontal direction W... ANT The component size is smaller than D H This allows the use of antennas of arbitrary size in the longitudinal direction.

[0613] For example, Figure 56A Indicates to Figure 52A The antenna configuration shown applies Figure 25A The example shown is a subarray consisting of a planar patch antenna with eight elements arranged vertically and a planar patch antenna with one element arranged horizontally. Furthermore, as... Figure 56B As shown, except Figure 56A In addition to the transmit array antennas shown, non-powered components (dummy components) can also be configured. By using non-powered components, the effects of inter-antenna coupling caused by adjacent antennas can be uniformized, thereby enabling uniformity of the pointing characteristics of each transmit antenna (Tx#1~Tx#4).

[0614] Thus, by using an antenna with a subarray structure in the antenna configuration of basic configuration 3, the directional gain of the antenna can be improved, thereby improving the detection performance (e.g., detection range) of the radar device 10.

[0615] The direction estimation unit 214 uses the received signal from the virtual receiving array obtained according to the above-described transceiver antenna configuration to perform direction estimation processing in the horizontal and vertical directions. Furthermore, the processing of the virtual receiving array in the direction estimation unit 214 for basic configuration 3 is the same as that for basic configuration 1, therefore, its description is omitted here.

[0616] Figure 57 For example, in such Figure 52A The diagram shows a MIMO array configuration using 4 transmit antennas 106 (Nt=4) and 4 receive antennas 202 (Na=4). H =0.5λ, D V An example of the direction estimation result when beamforming is used as the arrival direction estimation algorithm for the direction estimation unit 214, where λ = 0.5λ. That is, in Figure 57 In this design, the horizontal and vertical antenna spacing of the transmitting antenna 106 is 1λ or more, and the horizontal and vertical antenna spacing of the receiving antenna 202 is also 1λ or more. Furthermore, the directivity of each antenna was set to omnidirectional, and calculations were performed.

[0617] exist Figure 57 The output of the arrival direction estimation evaluation function value is plotted under the conditions that the target true value is set to 0 degrees horizontally and 0 degrees vertically, within the range of ±90 degrees in the horizontal direction and ±90 degrees in the vertical direction.

[0618] exist Figure 57 In this process, it can be confirmed that in directions other than the horizontal and vertical 0 degrees of the target true value, such as with... Figure 1A Compared to this, the number of grid lobes is reduced. For example, in Figure 57 In the meantime, the ratio of the peak power of the highest sidelobe (excluding the main lobe) in directions other than 0 degrees horizontally and vertically to the peak power of the main lobe in directions other than 0 degrees horizontally and vertically (PSLR) is about 0.3.

[0619] As described above, by using the MIMO array configuration of basic configuration 3, even if the element size in the longitudinal or transverse direction of the antennas used as the transmit and receive array antennas is about 1λ, the horizontal and vertical antenna spacing in the virtual receive array can be configured with an element spacing of about 0.5λ, thereby reducing grating lobes. Furthermore, for example, Figure 52A The virtual array elements of the virtual receiver array shown are configured without repetition, thus enabling an increase in the aperture length of the virtual receiver array and thereby improving angular resolution.

[0620] <Example 1 of the variation of basic configuration 3>

[0621] In basic configuration 3, the following structure is described: the number of transmitting antennas 106 and the number of receiving antennas 202 are 4 transmitting elements (Nt=4) and 4 receiving elements (Na=4) (for example, Figures 52A-52D A structure that transmits 3 elements (Nt=3) and receives 4 elements (Na=4) (for example, Figures 53A-53DA structure that transmits 4 elements (Nt=4) and receives 3 elements (Na=3) (for example, Figures 54A to 54D ), and a structure consisting of three transmitting elements (Nt=3) and three receiving elements (Na=3) as the minimum structure (e.g., Figures 55A to 55D However, the number of transmitting antennas Nt and the number of receiving antennas Na are not limited to these quantities.

[0622] In Variation 1 of Basic Configuration 3, a configuration that increases the number of antennas in the MIMO array compared to Basic Configuration 3 is described.

[0623] For example, the number N of transmitting antennas in the first transmitting antenna group of the transmitting array antenna can be increased. TxHGroup1_ANT and the number of antennas N contained in the second transmitting antenna group. TxHGroup2_ANT Additionally, the number N of antennas in the first receiving antenna group of the receiving array antenna can be increased. RxVGroup1_ANT and the number of antennas N contained in the second receiving vertical antenna group. RxVGroup2_ANT .

[0624] Figure 58 N represents TxHGroup1_ANT =2(Tx#2, Tx#4), N TxHGroup2_ANT =2(Tx#1, Tx#3), N RxVGroup1_ANT =3(Rx#1, Rx#2, Rx#3), N RxVGroup2_ANT Examples of MIMO array configurations with Rx#4, Rx#5, and Rx#6 = 3, and examples of virtual receiver array configurations. Furthermore, in... Figure 58 In the middle, although it represents (ΔH) Tx ΔV Rx )=(-D H -D V In the case of ), it can also be set as (ΔH). Tx ΔV Rx )=(-D H +D V ), (+D H -D V ), (+D H +D V ).

[0625] Figure 59 N represents TxHGroup1_ANT =2(Tx#2, Tx#4), N TxHGroup2_ANT =2(Tx#1, Tx#3), N RxVGroup1_ANT =3(Rx#1, Rx#2, Rx#3), N RxVGroup2_ANT Examples of MIMO array configurations with Rx#4 and Rx#5 = 2, and examples of virtual receiver array configurations. Furthermore, in... Figure 59 In the middle, although it represents (ΔH) Tx ΔV Rx )=(-D H -D V In the case of ), it can also be set as (ΔH). Tx ΔV Rx )=(+D H -D V ).

[0626] Figure 60 N represents TxHGroup1_ANT =4(Tx#2, Tx#4, Tx#6, Tx#8), N TxHGroup2_ANT =4(Tx#1, Tx#3, Tx#5, Tx#7), N RxVGroup1_ANT =3(Rx#1, Rx#2, Rx#3), N RxVGroup2_ANT Examples of MIMO array configurations with Rx#4, Rx#5, and Rx#6 = 3, and examples of virtual receiver array configurations. Furthermore, in... Figure 60 In the middle, although it represents (ΔH) Tx ΔV Rx )=(-D H -D V In the case of ), it can also be set as (ΔH). Tx ΔV Rx )=(-D H +D V ), (+D H -D V ), (+D H +D V ).

[0627] Figure 61 N represents TxHGroup1_ANT =3(Tx#2, Tx#4, Tx#6), N TxHGroup2_ANT =4(Tx#1, Tx#3, Tx#5, Tx#7), N RxVGroup1_ANT =3(Rx#1, Rx#2, Rx#3), N RxVGroup2_ANT Examples of MIMO array configurations with Rx#4, Rx#5, and Rx#6 = 3, and examples of virtual receiver array configurations. Furthermore, in... Figure 61 In the middle, although it represents (ΔH) Tx ΔV Rx )=(-D H -D V In the case of ), it can also be set as (ΔH). Tx ΔV Rx )=(-D H +D V ).

[0628] exist Figures 58-61 In the various MIMO array configurations shown, for example, D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0629] Additionally, for example, in Figures 58-61 In each of the virtual receiver arrays shown, each virtual array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, thereby improving the angular resolution.

[0630] In addition, it is possible to use D H D V Intervals, closely configured in Figures 58-61 The virtual array elements shown are located near the center of each virtual receiver array. Additionally, D... H D V The number of closely spaced virtual array elements depends on N. TxHGroup1_ANT N TxHGroup2_ANT N RxVGroup1_ANT and N RxVGroup2_ANT And increase.

[0631] For example, in a virtual receiver array, in the horizontal direction, (N TxHGroup1_ANT +N TxHGroup2_ANT ) virtual array elements in D H Alternating arrangement, in the vertical direction, (N) RxVGroup1_ANT +N RxVGroup2_ANT ) virtual array elements in D V Arranged at intervals. Additionally, in the virtual receiver array, (N) in the horizontal direction... TxHGroup1_ANT +N TxHGroup2_ANT ) - 2 Ds H Spacing of virtual array elements, and (N) in the vertical direction RxVGroup1_ANT +N RxVGroup2_ANT ) - 2 Ds V The spaced virtual array elements are arranged in a rectangular pattern.

[0632] Near the center of the virtual receiver array, at D H D V The more closely spaced the virtual array elements are arranged, the better the effect of reducing grating lobes and side lobes will be.

[0633] In addition, N TxGroup1_ANT N TxHGroup2_ANTThe larger the value of N, the greater the number of virtual array elements arranged horizontally. Therefore, the aperture length of the horizontal virtual receiving array can be increased, thereby improving the horizontal angular resolution. Similarly, N... RxVGroup1_ANT N RxVGroup2_ANT The larger the aperture, the greater the number of virtual array elements arranged along the vertical direction. Therefore, the aperture length of the virtual receiving array in the vertical direction can be increased, thereby improving the angular resolution in the vertical direction.

[0634] Figure 62 For example, in such Figure 60 The diagram shows a MIMO array configuration using 8 transmit antennas 106 (Nt=8) and 6 receive antennas 202 (Na=6). TxGroup1_ANT =4, N TxGroup2_ANT =4, N RxGroup1_ANT =3, N RxGroup2_ANT =3,D H =0.5λ, D V In the case of λ = 0.5λ, an example of the direction estimation result is given when beamforming is used as the arrival direction estimation algorithm for the direction estimation unit 214. Furthermore, calculations were performed with the directivity of each antenna set to omnidirectional.

[0635] exist Figure 62 The output of the arrival direction estimation evaluation function value is plotted within the horizontal ±90 degree range and the vertical ±90 degree range when the target true value is set to 0 degrees horizontally and 0 degrees vertically.

[0636] exist Figure 62 In this study, it was confirmed that grating lobe reduction was reduced in directions other than the horizontal and vertical 0 degrees of the target true value. For example, in Figure 62 In the study, it was confirmed that the peak power ratio (PSLR) of the highest sidelobe (excluding the main lobe) relative to the peak power of the main lobe in the horizontal and vertical 0-degree directions is approximately 0.13, for example, compared to... Figure 52A In comparison, by increasing N TxHGroup1_ANT N TxHGroup2_ANT and N RxVGroup1_ANT N RxVGroup2_ANT This improves the effect of reducing side lobes. Additionally, in Figure 62 In the middle, it is possible to confirm with Figure 57 In comparison, the peak of the main lobe also becomes sharper, by increasing N TxHGroup1_ANT N TxHGroup2_ANT and N RxVGroup1_ANT N RxVGroup2_ANT Angular resolution is improved.

[0637] <Example 2 of the variation of basic configuration 3>

[0638] The following describes antenna configuration methods 3-2A and 3-2B in variation 2 of basic configuration 3.

[0639] (Configuration Method 3-2A)

[0640] In variation 1 of basic configuration 3, the following situation is illustrated: by increasing the number N of receiving antennas in the receiving antenna group of the receiving array antenna... RxVGroup1_ANT N RxVGroup2_ANT This increases the number of virtual array elements arranged vertically. It is not limited to this; for example, it can be achieved by increasing the number N of transmit antenna groups in the transmit array antenna. TxGroup It can also increase the number of virtual array elements arranged vertically in the virtual receiver array.

[0641] In this case, although the vertical antenna spacing of the transmitting antenna group can be set to a fixed value (e.g., 2D), V However, this depends on the number of receiving antennas N contained in the receiving antenna group. RxVGroup1_ANT N RxVGroup2_ANT The virtual receiver array configuration will become a repeated configuration of the virtual array elements.

[0642] Therefore, in order to configure the virtual receiver array in a way that does not contain duplicate virtual array elements, for example, the interval D described below can be used. TxHGroupV This refers to the even-numbered antenna spacing in the vertical direction of the transmitting antenna group.

[0643] D TxHGroupV =D V (N RxVGroup1_ANT +N RxVGroup2_ANT -2) (15)

[0644] For example, in N RxVGroup1_ANT =N RxVGroup2_ANT When D = 2 TxHGroupV =2D V In N RxVGroup1_ANT =N RxVGroup2_ANT When D = 3 TxHGroupV =4D V .

[0645] For example, in the number N of transmitting antenna groups TxHGroup When the number of antennas is 3, the spacing between the three transmitting antenna groups is set to {2D}. V D TxHGroupV Additionally, regarding the number N of transmitting antenna groups... TxHGroup When the number of antennas is 4, the spacing between the four transmitting antenna groups is set to {2D}. V D TxHGroupV 2D VSimilarly, in N RxGroup_ANT When the number of antennas is 5, the spacing between the 5 transmitting antenna groups is set to {2D}. V D TxHGroupV 2D V D TxHGroupV}

[0646] Figure 63 N represents RxVGroup =2, N TxHGroup =4, N TxHGroup1_ANT =2, N TxHGroup2_ANT =2, N TxHGroup3_ANT =2, N TxHGroup4_ANT =2, N RxVGroup1_ANT =2, N RxVGroup2_ANT Examples of MIMO array configurations with N=2, and examples of virtual receiver array configurations. Furthermore, "N TxHGroup3_ANT "N" indicates the number of transmitting antennas contained in the third transmitting antenna group. TxHGroup4_ANT This indicates the number of transmitting antennas contained in the 4th transmitting antenna group. Figure 63 In equation (15), D TxHGroupV =2D V .

[0647] In addition, Figure 63 In the diagram, ΔV represents the offset of the second receiving antenna group (Rx#3, Rx#4) relative to the first receiving antenna group (Rx#1, Rx#2). Rx(2，1) For ΔV Rx(2，1) =-D V However, it can also be set as ΔV. Rx(2，1) =+D V .

[0648] In addition, Figure 63 In the middle, the offset ΔH between the second transmitting antenna group (Tx#3, Tx#7) and the first transmitting antenna group (Tx#4, Tx#8) is... Tx(2，1) Set to -D H The offset ΔH between the third transmitting antenna group (Tx#2, Tx#6) and the second transmitting antenna group Tx(3，2) Set as +D H And the offset ΔH between the fourth transmitting antenna group (Tx#1, Tx#5) and the third transmitting antenna group. Tx(4，3) Set to -D H However, the offset can also be of two types (+D). V -D V Any combination of ). Furthermore, in Figure 63 In the middle, +D V Set the direction to up, and use -D V Set it to the down direction, and add +D HSet the direction to the right, and use -D H Set it to the left direction.

[0649] in addition, Figure 64 N represents RxVGroup =2, N TxHGroup =4, N TxHGroup1_ANT =2, N TxHGroup2_ANT =2, N TxHGroup3_ANT =2, N TxHGroup4_ANT =2, N RxVGroup1_ANT =3, N RxVGroup2_ANT Examples of MIMO array configurations with a value of 3, and examples of virtual receiver array configurations. Figure 64 In equation (15), D TxHGroupV =4D V .

[0650] In addition, Figure 64 In the diagram, ΔV represents the offset of the second receiving antenna group (Rx#4, Rx#5, Rx#6) relative to the first receiving antenna group (Rx#1, Rx#2, Rx#3). Rx(2，1) For ΔV Rx(2，1) =-D V However, it can also be set as ΔV. Rx(2，1) =+D V .

[0651] In addition, Figure 64 In the middle, the offset ΔH between the second transmitting antenna group (Tx#3, Tx#7) and the first transmitting antenna group (Tx#4, Tx#8) is... Tx(2，1) Set to -D H The offset ΔH between the third transmitting antenna group (Tx#2, Tx#6) and the second transmitting antenna group Tx(3，2) Set as +D H The offset ΔH between the fourth transmitting antenna group (Tx#1, Tx#5) and the third transmitting antenna group Tx(4，3) Set to -D H However, the offset can also be of two types (+D). V -D V Any combination of ). Furthermore, in Figure 64 In the middle, +D V Set the direction to up, and use -D V Set it to the down direction, and add +D H Set the direction to the right, and use -D H Set it to the left direction.

[0652] Furthermore, unequal intervals (e.g., greater than D) may be included near the center of the virtual receiver array. H and D V In the case of the interval) configuration, D TxHGroupVIt can also be a value larger than that in equation (15).

[0653] (Configuration Method 3-2B)

[0654] In variation 1 of basic configuration 3, the following situation is illustrated: by increasing the number N of transmitting antennas in each transmitting antenna group of the transmitting array antenna... TxHGroup1_ANT N TxHGroup2_ANT This involves increasing the number of virtual array elements arranged horizontally. It's not limited to this; for example, it can be achieved by increasing the number N of the receiving antenna groups in the receiving array antenna. RxVGroup It can also increase the number of virtual array elements arranged horizontally in the virtual receiver array.

[0655] In this case, although the horizontal antenna spacing of the receiving antenna group can be set to a fixed value (e.g., 2D), H However, this depends on the number of transmitting antennas N contained in the transmitting antenna group. TxHGroup1_ANT N TxHGroup2_ANT The virtual receiver array configuration will become a repeated configuration of the virtual array elements.

[0656] Therefore, in order to configure the virtual receiver array in a way that does not contain duplicate virtual array elements, for example, the interval D described below can be used. RxVGroupH This is the even-numbered interval in the horizontal spacing of the receiving antenna group.

[0657] D RxVGroupH =D H (N TxHGroup1_ANT +N TxHGroup2_ANT -2) (16)

[0658] For example, in N TxHGroup1_ANT =N TxHGroup2_ANT When D = 2 RxVGroupH =2D H In N TxHGroup1_ANT =N TxHGroup2_ANT When D = 3 RxVGroupH =4D H .

[0659] For example, in the number N of receiving antenna groups RxVGroup When the number of antennas is 3, the horizontal spacing between the three receiving antenna groups is set to {2D}. H D RxVGroupH Additionally, regarding the number N of receiving antenna groups... RxVGroup When the number of antennas is 4, the horizontal spacing of the four receiving antenna groups is set to {2D}. H D RxVGroupH 2D H Similarly, when the number of receiving antenna groups N...RxVGroup When the number of antennas is 5, the horizontal spacing of the 5 receiving antenna groups is set to {2D}. H D RxVGroupH 2D H D RxVGroupH}

[0660] Figure 65 N represents TxHGroup =2, N RxVGroup =4, N TxHGroup1_ANT =2, N TxHGroup2_ANT =2, N RxVGroup1_ANT =2, N RxVGroup2_ANT =2, N RxVGroup3_ANT =2, N RxVGroup4_ANT Examples of MIMO array configurations with N=2, and examples of virtual receiver array configurations. Furthermore, "N RxVGroup3_ANT "N" indicates the number of receiving antennas contained in the third receiving antenna group. RxVGroup4_ANT This indicates the number of receiving antennas contained in the 4th receiving antenna group. Figure 65 In equation (16), D RxVGroupH =2D H .

[0661] In addition, Figure 65 In the diagram, ΔH represents the offset of the second transmitting antenna group (Tx#1, Tx#3) relative to the first transmitting antenna group (Tx#2, Tx#4). Tx(2，1) For ΔH Tx(2，1) =-D H However, it can also be set as ΔH. Tx(2，1) =+D H .

[0662] In addition, Figure 65 In the middle, the offset ΔV between the second receiving antenna group (Rx#3, Rx#4) and the first receiving antenna group (Rx#1, Rx#2) is... Rx(2，1) Set to -D V The offset ΔV between the third receiving antenna group (Rx#5, Rx#6) and the second receiving antenna group Rx(3，2) Set as +D V And the offset ΔV of the fourth receiving antenna group (Rx#7, Rx#8) relative to the third receiving antenna group. Rx(4，3) Set to -D V However, the offset can also be of two types (+D). V -D V Any combination of ). Furthermore, in Figure 65 In the middle, +D V Set the direction to up, and use -D V Set it to the downward direction.

[0663] Figure 66 N represents TxHGroup =2, N RxVGroup =4, N TxHGroup1_ANT =3, N TxHGroup2_ANT =3, N RxVGroup1_ANT =2, N RxVGroup2_ANT =2, N RxVGroup3_ANT =2, N RxVGroup4_ANT Examples of MIMO array configurations with a value of 2, and examples of virtual receiver array configurations. Figure 66 In equation (16), D RxVGroupH =4D H .

[0664] Furthermore, this indicates the offset ΔH between the second transmitting antenna group (Tx#1, Tx#3, Tx#5) and the first transmitting antenna group (Tx#2, Tx#4, Tx#6). Tx(2，1) For ΔH Tx(2，1) =-D H However, it can also be set as ΔH. Tx(2，1) =+D H .

[0665] In addition, Figure 66 In the middle, the offset ΔV between the second receiving vertical antenna group (Rx#3, Rx#4) and the first receiving antenna group (Rx#1, Rx#2) is... Rx(2，1) Set to -D V The offset ΔV between the third receiving antenna group (Rx#5, Rx#6) and the second receiving antenna group Rx(3，2) Set as +D V And the offset ΔV of the fourth receiving antenna group (Rx#7, Rx#8) relative to the third receiving antenna group. Rx(4，3) Set to -D V However, the offset can also be of two types (+D). V -D V Any combination of ). Furthermore, in Figure 66 In the middle, +D V Set the direction to up, and use -D V Set it to the down direction, and add +D H Set the direction to the right, and use -D H Set it to the left direction.

[0666] Additionally, unequal intervals (e.g., greater than D) can be included near the center of the virtual receiver array. H and D V In the case of the interval) configuration, D RxVGroupH It can also be a value larger than that in equation (16).

[0667] The above describes configuration method 3-2A and configuration method 3-2B in variation 2 of basic configuration 3.

[0668] For example, in Figures 63-66 In the transmit / receive antenna configuration shown (e.g., MIMO array configuration), for example, D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0669] Additionally, for example, in Figures 63-66 In the virtual receiver array shown, each virtual array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, thereby improving the angular resolution.

[0670] Additionally, for example, it is possible to use D H D V Intervals, closely configured in Figures 63-66 The virtual array elements shown are located near the center of the virtual receiver array. Additionally, D... H D V The number of closely spaced virtual array elements depends on the number of transmit antenna groups N. TxHGroup and the number of transmitting antennas N in each transmitting antenna group TxHGroup(ntvg)_ANT (Here, ntvg = 1, ..., N) TxHGroup The number of receiving antenna groups N) RxVGroup and the number of receiving antennas N in each receiving antenna group RxVGroup(nrhg)_ANT (Here, nrhg = 1, ..., N) RxVGroup And thus increase.

[0671] For example, in a virtual receiver array, in the horizontal direction, 0.5×(N) TxHGroup1_ANT +N TxHGroup2_ANT )×N RxVGroup A virtual array element with D H The intervals are arranged in columns, and in the vertical direction, 0.5 × (N) RxVGroup1_ANT +N RxVGroup2_ANT )×N TxHGroup A virtual array element with D V The intervals are arranged in columns. Additionally, 0.5 × (N) in the horizontal direction... TxHGroup1_ANT +N TxHGroup2_ANT )×N RxVGroup -2 Ds H Spacing of virtual array elements, and 0.5×(N) in the vertical direction. RxVGroup1_ANT +N RxVGroup2_ANT )×N TxHGroup -2 DsV The spaced virtual array elements are arranged in a rectangular pattern.

[0672] Near the center of the virtual receiver array, at D H D V The more closely spaced virtual array elements are added, the better the effect of reducing grating lobes and side lobes can be.

[0673] In addition, the number N of transmitting antennas contained in each transmitting antenna group TxHGroup(ntvg)_ANT and the number of receiving antenna groups N RxVGroup The larger the value, the greater the number of virtual array elements arranged horizontally. Therefore, the aperture length of the horizontal virtual receiving array can be increased, thereby improving the horizontal angular resolution. Similarly, the number of receiving antennas N in each receiving antenna group... RxVGroup(nrhg)_ANT and the number of transmitting antenna groups N TxHGroup The larger the aperture, the greater the number of virtual array elements arranged along the vertical direction. Therefore, the aperture length of the virtual receiving array in the vertical direction can be increased, thereby improving the angular resolution in the vertical direction.

[0674] Furthermore, in variation 2 of basic configuration 3, a configuration combining configuration method 3-2A and configuration method 3-2B can also be used.

[0675] Figure 67 N represents RxVGroup =N TxHGroup =4, N TxHGroup1_ANT =N TxHGroup2_ANT =N TxHGroup3_ANT =N TxHGroup4_ANT =2, N RxVGroup1_ANT =N RxVGroup2_ANT =N RxVGroup3_ANT =N RxVGroup4_ANT Examples of MIMO array configurations with a value of 2, and examples of virtual receiver array configurations. Figure 67 In equation (15), D TxHGroupV =2D V D in equation (16) RxVGroupH =2D H .

[0676] In addition, Figure 67 In the middle, the offset ΔH between the second transmitting antenna group (Tx#3, Tx#7) and the first transmitting antenna group (Tx#4, Tx#8) is... Tx(2，1) Set to -D H The offset ΔH between the third transmitting antenna group (Tx#2, Tx#6) and the second transmitting antenna group Tx(3，2) Set to -D HThe offset ΔH between the fourth transmitting antenna group (Tx#1, Tx#5) and the third transmitting antenna group Tx(4，3) Set to -D H However, the offset can also be of two types (+D). V -D V Any combination of ).

[0677] In addition, Figure 67 In the diagram, the offset ΔV between the second receiving antenna group (Rx#3, Rx#4) and the first receiving antenna group (Rx#1, Rx#2) is... Rx(2，1) Set to -D V The offset ΔV between the third receiving antenna group (Rx#5, Rx#6) and the second receiving antenna group Rx(3，2) Set as +D V The offset ΔV between the fourth receiving antenna group (Rx#7, Rx#8) and the third receiving antenna group Rx(4，3 Set to -D V However, the offset can also be of two types (+D). V -D V Any combination of ).

[0678] In addition, Figure 67 In the middle, +D V Set the direction to up, and use -D V Set the direction to down, and add +D. H Set the direction to the right, and use -D H Set the direction to the left.

[0679] in addition, Figure 68A N represents RxVGroup =N TxHGroup =4, N TxHGroup1_ANT =N TxHGroup2_ANT =N TxHGroup3_ANT =N TxHGroup4_ANT =4, N RxVGroup1_ANT =N RxVGroup2_ANT =N RxVGroup3_ANT =N RxVGroup4_ANT Example of MIMO array configuration with 4 = 4 Figure 68B This represents a virtual receiver array configuration example. Figure 68A In equation (15), D TxHGroupV =6D V D in equation (16) RxVGroupH =6D H .

[0680] In addition, Figure 68AIn the above, the offset ΔH between the second transmitting antenna group (Tx#3, Tx#7, Tx#11, Tx#15) and the first transmitting antenna group (Tx#4, Tx#8, Tx#12, Tx#16) is determined. Tx(2，1) Set to -D H The offset ΔH between the third transmitting antenna group (Tx#2, Tx#6, Tx#10, Tx#14) and the second transmitting antenna group. Tx(3，2) Set as +D H The offset ΔH between the fourth transmitting antenna group (Tx#1, Tx#5, Tx#9, Tx#13) and the third transmitting antenna group. Tx(4，3) Set to -D H However, the offset can also be of two types (+D). V -D V Any combination of ).

[0681] In addition, Figure 68A In the diagram, the offset ΔV between the second receiving antenna group (Rx#5, Rx#6, Rx#7, Rx#8) and the first receiving antenna group (Rx#1, Rx#2, Rx#3, Rx#4) is defined. Rx(2，1) Set to -D V The offset ΔV between the third receiving antenna group (Rx#9, Rx#10, Rx#11, Rx#12) and the second receiving antenna group. Rx(3，2) Set as +D V The offset ΔV of the fourth receiving antenna group (Rx#13, Rx#14, Rx#15, Rx#16) relative to the third receiving antenna group Rx(4，3) Set to -D V However, the offset can also be of two types (+D). V -D V Any combination of ).

[0682] In addition, Figure 68A and Figure 68B In the middle, +D V Set the direction to up, and use -D V Set the direction to down, and add +D. H Set the direction to the right, and use -D H Set the direction to the left.

[0683] <Basic Configuration 4>

[0684] Figure 69 Examples of configurations for the transmitting antenna 106 and receiving antenna 202 in basic configuration 4, and examples of configurations for the virtual receiving array.

[0685] (1) Configuration of transceiver antennas

[0686] exist Figure 69 In the transmitting array antenna, the number of transmitting antennas 106 is Nt = 4 (Tx#1, Tx#2, Tx#3 and Tx#4), and the number of receiving antennas 202 is Na = 4 (Rx#1, Rx#2, Rx#3 and Rx#4).

[0687] Figure 69 The transmitted array antenna shown is, for example, composed of a "first transmitted antenna group" ( Figure 69 Tx#2, Tx#4) and "second transmitting antenna group" ( Figure 69 The antennas consist of Tx#1 and Tx#3. Each transmitting antenna group contains two transmitting antenna elements, which are spaced 2D apart in the horizontal direction. H The vertical interval is D. V . Figure 69 The adjacent transmitting antennas of each of the shown transmitting antenna groups are horizontally spaced 2D apart. H The interval (in other words, D) H Arranged at twice the interval, and separated by D in the vertical direction. V They are configured at intervals. In other words, in Figure 69 In the middle, the transmitting antennas contained in each transmitting antenna group are arranged in a 2D horizontal direction. H D in the vertical direction V The antenna spacing is arranged in a straight line along the right-downward direction (in other words, the left-upward direction).

[0688] In addition, Figure 69 In the middle, relative to the first transmitting antenna group, the second transmitting antenna group is offset to the left along the horizontal direction by D. H And offset 2D vertically downwards. V Location configuration. In other words, Figure 69 The adjacent transmitting antenna groups shown are offset by D in the horizontal direction. H The interval, and offset by 2D in the vertical direction. V (In other words, D) V The relationship is (twice the interval).

[0689] in addition, Figure 69 The received array antenna shown is, for example, composed of a "first received antenna group" ( Figure 69 Rx#2, Rx#4) and "second receiving antenna group" ( Figure 69 The antennas are composed of Rx#1 and Rx#3. Each receiving antenna group contains two receiving antenna elements, and the horizontal spacing between these two receiving antenna elements is 2D. H The antenna spacing in the vertical direction is D. V . Figure 69The adjacent receiving antennas of each of the shown receiving antenna groups are horizontally spaced 2D apart. H The interval (in other words, D) H Arranged at twice the interval, and separated by D in the vertical direction. V They are configured at intervals. In other words, in Figure 69 In the middle, the receiving antennas contained in each receiving antenna group are arranged in a 2D horizontal direction. H D in the vertical direction V The antenna spacing is arranged in a straight line along the right-upward direction (in other words, the left-downward direction).

[0690] In addition, Figure 69 In the middle, relative to the first receiving antenna group, the second receiving antenna group is offset to the right by D in the horizontal direction. H And offset 2D vertically downwards. V Location configuration. In other words, Figure 69 The adjacent receiving antenna groups shown are offset by D along the horizontal direction. H The interval, and offset by 2D along the vertical direction. V (In other words, D) V The relationship is (twice the interval).

[0691] Additionally, for example, such as Figure 69 As shown, transmitting antennas Tx#1 to Tx#4 are each positioned at different locations in both the horizontal and vertical directions. Similarly, as... Figure 69 As shown, receiving antennas Rx#1 to Rx#4 are each configured in different positions in the horizontal and vertical directions.

[0692] In addition, Figure 69 In the transmit and receive antenna configuration shown, the respective positions of the transmit antennas and the respective positions of the receive antennas are, for example, linearly symmetrical about a line parallel to the horizontal or vertical direction (in other words, reversed).

[0693] For example, suppose Figure 69 The horizontal direction shown corresponds to the X-axis. Figure 69 The vertical direction shown corresponds to the Y-axis direction.

[0694] exist Figure 69 In the case of the antenna configuration shown, the position coordinates of the transmitting antenna 106 constituting the transmitting array antenna are the same as the position coordinates of the transmitting antenna Tx#1 (X). T_#1 Y T_#1 Based on the reference, the position coordinates (X) of the transmitting antenna Tx#2 are represented as follows. T_#2 Y T_#2 )=(XT_#1 +D H Y T_#1 +2D V ), the position coordinates (X) of transmitting antenna Tx#3 T_#3 Y T_#3 )=(X T_#1 +2D H Y T_#1 -D V ), the position coordinates (X) of transmitting antenna Tx#4 T_#4 Y T_#4 )=(X T_#1 +3D H Y T_#1 +D V ).

[0695] Similarly, the position coordinates of the receiving antenna 202 constituting the receiving array antenna are the same as the position coordinates of the receiving antenna Rx#1 (X R_#1 Y R_#1 Based on the reference, the position coordinates (X) of the receiving antenna Rx#2 are represented as follows. R_#2 Y R_#2 )=(X R_#1 -D H Y R_#1 +2D V ), the position coordinates (X) of receiving antenna Rx#3 R_#3 Y R_#3 )=(X R_#1 +2D H Y R_#1 +D V ), the position coordinates of receiving antenna Rx#4 (X R_#4 Y R_#4 )=(X R_#1 +D H Y R_#1 +3D V ).

[0696] (2) Configuration of the virtual receiver array

[0697] According to the above Figure 69 The configuration of the virtual receiving array (virtual antenna VA#1 to virtual antenna VA#16) formed by the transmitting and receiving antenna configuration shown has the following characteristics.

[0698] For example, according to Figure 69 The configuration of the transmitting array antenna and the receiving array antenna are shown, along with the position coordinates (X, Y, F) of the virtual receiving arrays VA#1 to VA#16. V_#1 Y V_#1 )~(X V_#16 Y V_#16The details are as follows. Furthermore, VA#1 is represented here as the location reference (0, 0) of the virtual receiving array.

[0699] (0, 0), (D) H 2D V (2D) H -D V ), (3D) H D V ), (-D H 2D V (0, 4D) V ), (D H D V (2D) H 3D V (2D) H D V ), (3D) H 3D V (4D) H ,0), (5D H 2D V ), (D H 3D V (2D) H 5D V ), (3D) H 2D V (4D) H 4D V )

[0700] Thus, in Figure 69 In the configuration of the virtual receiver array shown, each virtual receiver array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, resulting in a narrower main lobe and thus improved angular resolution.

[0701] Additionally, located Figure 69 The virtual array elements VA#2, VA#7, VA#9, VA#4, VA#15, VA#10, VA#8, and VA#13 near the center of the virtual receiving array shown are arranged horizontally along the direction of D. H The spacing is closely arranged, and along the vertical direction at D V The spacing is closely spaced. As an example, in... Figure 69 In the middle, the interval D H and interval D V With a value set to approximately 0.5λ, the virtual array elements VA#2, VA#7, VA#9, VA#4, VA#15, VA#10, VA#8, and VA#13 are arranged horizontally along the direction of D. H =0.5λ interval configuration, and along the vertical direction with D V=0.5λ interval configuration. Therefore, compared with basic configuration 1 (for example, refer to...) Figure 8 Similarly, it can reduce the number of grid lobes.

[0702] In addition, Figure 69 Near the center of the virtual receiving array shown, there is a lack of [something] with interval D. H and interval D V The elements at the coordinates corresponding to the positions are surrounded by closely arranged virtual array elements (e.g., VA#2, VA#7, VA#9, VA#4, VA#15, VA#10, VA#8, and VA#13). However, the radar device 10, for example, uses elements spaced D to surround the missing parts. H and interval D V The received signals of the closely arranged virtual array elements are interpolated, thereby enabling the received signals of the elements in the missing part to be received approximately.

[0703] Additionally, for example, in the MIMO array configuration of basic configuration 4, the interval D is... H and interval D V With a value of approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0704] Therefore, for example, it is possible to apply such as Figure 9A The antenna shown (where the antenna width W) ANT <2D H Antenna height H ANT <2D V As Figure 69 The antenna elements of at least one of the transmitting array antennas and receiving array antennas shown are as follows: Figure 9A The antenna shown uses a four-element subarray, consisting of two planar patch antennas arranged horizontally and vertically. For example, Figure 70A Indicates to Figure 69 The transmitted antenna configuration shown applies Figure 9A The example shown is a subarray consisting of two planar patch antennas arranged vertically and two planar patch antennas arranged horizontally.

[0705] Additionally, as long as the transverse direction W of the transmitting antenna 106 and the receiving antenna 202 is... ANT The component size is smaller than D H This allows the use of antennas of arbitrary size in the longitudinal direction. For example, Figure 70B Indicates to Figure 69 The antenna configuration shown applies Figure 25AThe example shown is a subarray consisting of a planar patch antenna with eight elements arranged vertically and a planar patch antenna with one element arranged horizontally. In addition, besides... Figure 70B In addition to the transmit array antenna shown, non-powered components (dummy components) (not shown) can also be configured.

[0706] Thus, by using an antenna with a subarray structure in the antenna configuration of basic configuration 4, the directional gain of the antenna can be improved, thereby improving the detection performance (e.g., detection range) of the radar device 10.

[0707] The direction estimation unit 214 uses the received signal from the virtual receiving array obtained according to the above-described transceiver antenna configuration to perform direction estimation processing in the horizontal and vertical directions. Furthermore, the processing of the virtual receiving array in the direction estimation unit 214 for basic configuration 4 is the same as that for basic configuration 1, therefore, its description is omitted here.

[0708] Figure 71 For example, in such Figure 69 The diagram shows a MIMO array configuration using 4 transmit antennas 106 (Nt=4) and 4 receive antennas 202 (Na=4). H =0.5λ, D V An example of the direction estimation result when beamforming is used as the arrival direction estimation algorithm for the direction estimation unit 214, where λ = 0.5λ. That is, in Figure 71 In this design, the horizontal and vertical antenna spacing of the transmitting antenna 106 is 1λ or more, and the horizontal and vertical antenna spacing of the receiving antenna 202 is also 1λ or more. Furthermore, the directivity of each antenna was set to omnidirectional, and calculations were performed.

[0709] exist Figure 71 The output of the arrival direction estimation evaluation function value is plotted within the horizontal ±90 degree range and the vertical ±90 degree range when the target true value is set to 0 degrees horizontally and 0 degrees vertically.

[0710] exist Figure 71 In this process, it can be confirmed that in directions other than the horizontal and vertical 0 degrees of the target true value, such as with... Figure 1A Compared to this, the number of grid lobes is reduced. For example, in Figure 71 In the meantime, the ratio of the peak power of the highest sidelobe (excluding the main lobe) in directions other than 0 degrees horizontally and vertically to the peak power of the main lobe in directions other than 0 degrees horizontally and vertically (PSLR) is about 0.35.

[0711] As described above, by using the MIMO array configuration of basic configuration 4, even if the element size in the longitudinal or transverse direction of the antennas used as the transmit and receive array antennas is about 1λ, the horizontal and vertical antenna spacing in the virtual receive array can be configured with an element spacing of about 0.5λ, thereby reducing grating lobes. Furthermore, for example, Figure 69 The virtual array elements of the virtual receiver array shown are configured without repetition, thus enabling an increase in the aperture length of the virtual receiver array and thereby improving angular resolution.

[0712] <Example 1 of the variation of basic configuration 4>

[0713] In basic configuration 4 (for example, Figure 69 The document describes the case where the number of transmitting antennas 106 is set to 4 elements (Nt = 4), and the number of receiving antennas 202 is set to 4 elements (Na = 4). However, the number of transmitting antennas Nt and the number of receiving antennas Na are not limited to these numbers.

[0714] In variation 1 of basic configuration 4, for example, it is explained that... Figure 69 The antenna configuration shown is a basic structure with the addition of transmitting antennas Nt and receiving antennas Na.

[0715] The following describes the antenna configuration methods 4-1A, 4-1B, 4-1C and 4-1D in the variation 1 of the basic configuration 4.

[0716] (Configuration Method 4-1A)

[0717] For example, the transmit array antenna consists of a first transmit antenna group and a second transmit antenna group. Furthermore, each transmit antenna group includes multiple transmit antenna elements, which are arranged in a 2D configuration in the horizontal direction. H D in the vertical direction V The antenna spacing is arranged in a straight line along the right-downward direction.

[0718] In addition, the second transmitting antenna group is offset to the left by D relative to the first transmitting antenna group. H And offset downwards by 2D V Location configuration.

[0719] Here, the number of transmitting antennas in the first transmitting antenna group is set to "N". TxLowerRightGr1_ANT For example, N TxLowerRightGr1_ANT ≥2. Additionally, the number of transmitting antennas in the second transmitting antenna group is set to "N". TxLowerRightGr2_ANT For example, N TxLowerRightGr2_ANT ≧2.

[0720] Furthermore, the receiving array antenna consists of a first receiving antenna group and a second receiving antenna group. Additionally, each receiving antenna group includes multiple receiving antenna elements, which are arranged in a 2D configuration in the horizontal direction. H D in the vertical direction V The intervals are arranged in a straight line along the upper right direction.

[0721] In addition, the second receiving antenna group is offset to the right by D relative to the first receiving antenna group. H And offset downwards by 2D V Location configuration.

[0722] Here, the number of receiving antennas in the first receiving antenna group is set to "N". RxUpperRightGr1_ANT For example, N RxUpperRightGr1_ANT ≥2. Additionally, the number of receiving antennas in the second receiving antenna group is set to "N". RxUpperRightGr2_ANT For example, N RxUpperRightGr2_ANT ≧2.

[0723] Figure 72 N represents TxLowerRightGr1_ANT =4(Tx#2, Tx#4, Tx#6, Tx#8), N TxLowerRightGr2_ANT =4(Tx#1, Tx#3, Tx#5, Tx#7), N RxUpperRightGr1_ANT =2(Rx#2, Rx#4), N RxUpperRightGr2_ANT Examples of MIMO array configurations and virtual receiver array configurations when the array has 2 (Rx#1, Rx#3).

[0724] in addition, Figure 73 N represents TxLowerRightGr1_ANT =2(Tx#2, Tx#4), N TxLowerRightGr2_ANT =2(Tx#1, Tx#3), N RxUpperRightGr1_ANT =3(Rx#2, Rx#4, Rx#6), N RxUpperRightGr2_ANT Examples of MIMO array configurations and virtual receiver array configurations with a range of 3 (Rx#1, Rx#3, Rx#5).

[0725] in addition, Figure 74 N represents TxLowerRightGr1_ANT =4(Tx#2, Tx#4, Tx#6, Tx#8), N TxLowerRightGr2_ANT =4(Tx#1, Tx#3, Tx#5, Tx#7), N RxUpperRightGr1_ANT =3(Rx#2, Rx#4, Rx#6), N RxUpperRightGr2_ANT Examples of MIMO array configurations and virtual receiver array configurations with a range of 3 (Rx#1, Rx#3, Rx#5).

[0726] exist Figure 72 , Figure 73 and Figure 74 In the various MIMO array configurations shown, for example, D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0727] Additionally, for example, in Figure 72 , Figure 73 and Figure 74 In the virtual receiver arrays shown, although some elements of each virtual array are arranged in overlapping positions, the angular resolution can be improved because the aperture length of the virtual receiver array can be increased. Furthermore, in Figure 72 and Figure 73 In this context, the virtual array elements are not repeated. Figure 74 In the middle, the virtual array element is repeated in two places.

[0728] In addition, it is possible to use D H D V Intervals, closely configured in Figure 72 , Figure 73 and Figure 74 The virtual array elements are shown near the center of each virtual receiver array. Additionally, as... Figure 72 , Figure 73 and Figure 74 As shown, near the center of each virtual receiver array, elements corresponding to certain coordinate positions are missing. However, radar device 10 uses a perimeter surrounding these missing positions with D... H D V The received signals of closely spaced virtual array elements are interpolated, thereby enabling the approximate reception of the received signal of the missing element.

[0729] In addition, closely configured in Figure 72 , Figure 73 and Figure 74 The number of virtual array elements near the center of each virtual receiver array shown will depend on N. TxLowerRightGr1_ANT N TxLowerRightGr2_ANT N RxUpperRightGr1_ANT N RxUpperRightGr2_ANT And increase.

[0730] For example, in a virtual receiver array, in the horizontal direction, (N TxLowerRightGr1_ANT +N TxLowerRightGr2_ANT +N RxUpperRightGr1_ANT +N RxUpperRightGr2_ANT ) - 5 virtual array elements in D H Arranged at intervals, in the vertical direction, 0.5×(N) TxLowerRightGr1_ANT +N TxLowerRightGr2_ANT+N RxUpperRightGr1_ANT +N RxUpperRightGr2_ANT ) - 1 virtual array element with D V Arranged at intervals. In the virtual receiver array, with D... H D V The more closely spaced the virtual array elements are arranged, the better the effect of reducing grating lobes and side lobes will be.

[0731] In addition, N TxLowerRightGr1_ANT N TxLowerRightGr2_ANT N RxUpperRightGr1_ANT N RxUpperRightGr2_ANT The larger the aperture, the greater the number of virtual array elements arranged along the horizontal and vertical directions. Therefore, it is possible to increase the aperture length of the virtual receiving array in the horizontal and vertical directions, thereby improving the angular resolution in the horizontal and vertical directions.

[0732] Figure 75 For example, in such Figure 74 The diagram shows a MIMO array configuration using 8 transmit antennas 106 (Nt=8) and 6 receive antennas 202 (Na=6). TxLowerRightGr1_ANT =N TxLowerRightGr2_ANT =4, N RxUpperRightGr1_ANT =N RxUpperRightGr2_ANT =3,D H =0.5λ, D V In the case of λ = 0.5λ, an example of the direction estimation result is given when beamforming is used as the arrival direction estimation algorithm for the direction estimation unit 214. Furthermore, calculations were performed with the directivity of each antenna set to omnidirectional.

[0733] exist Figure 75 The output of the arrival direction estimation evaluation function value is plotted within the horizontal ±90 degree range and the vertical ±90 degree range when the target true value is set to 0 degrees horizontally and 0 degrees vertically.

[0734] exist Figure 75 In this process, it can be confirmed that in directions other than the horizontal and vertical 0 degrees of the target true value, such as with... Figure 1A Compared to this, the number of grid lobes is reduced. For example, in Figure 75 In the study, it was confirmed that the peak power ratio (PSLR) of the highest side lobe (excluding the main lobe) relative to the peak power ratio of the main lobe in the horizontal and vertical 0-degree directions is approximately 0.28, for example, compared to... Figure 69 The structure of basic configuration 4 shown (N) TxLowerRightGr1_ANT =N TxLowerRightGr2_ANT =N RxUpperRightGr1_ANT =N RxUpperRightGr2_ANT =2 cases) (For example, refer to Figure 71 Compared to, by increasing N TxLowerRightGr1_ANT NTxLowerRightGr2_ANT N RxUpperRightGr1_ANT N RxUpperRightGr2_ANT This improves the effect of reducing side lobes. Additionally, in Figure 75 In the middle, it is possible to confirm with Figure 71 In comparison, the peak of the main lobe also becomes sharper, by increasing N TxLowerRightGr1_ANT N TxLowerRightGr2_ANT N RxUpperRightGr1_ANT N RxUpperRightGr2_ANT Angular resolution is improved.

[0735] Furthermore, the more N increases TxLowerRightGr1_ANT N TxLowerRightGr2_ANT N RxUpperRightGr1_ANT N RxUpperRightGr2_ANT Compared to the vertical direction, it can expand the aperture length of the virtual array in the horizontal direction, thus becoming a MIMO array structure that can more easily improve the angular resolution in the horizontal direction compared to the angular resolution in the vertical direction.

[0736] (Configuration Method 4-1B)

[0737] In configuration method 4-1B, the aperture length of the virtual receiving array is increased in the vertical direction compared to the horizontal direction. This results in a MIMO array structure that further improves the angular resolution in the vertical direction compared to the horizontal angular resolution.

[0738] For example, the transmit array antenna consists of a first transmit antenna group and a second transmit antenna group. Furthermore, each transmit antenna group includes multiple transmit antenna elements, which are arranged in a horizontal direction at a D-shape. H 2D in the vertical direction V The antenna spacing is arranged in a straight line along the upper right direction.

[0739] In addition, the second transmitting antenna group is offset to the right by 2D relative to the first transmitting antenna group. H And offset downwards by D V Location configuration.

[0740] Here, the number of transmitting antennas in the first transmitting antenna group is set to "N". TxUpperRightGr1_ANT For example, N TxUpperRightGr1_ANT ≥2. Additionally, the number of transmitting antennas in the second transmitting antenna group is set to "N". TxUpperRightGr2_ANT For example, N TxUpperRightGr2_ANT ≧2.

[0741] Furthermore, the receiving array antenna consists of a first receiving antenna group and a second receiving antenna group. Additionally, each receiving antenna group contains multiple receiving antenna elements, which are arranged at a horizontal angle D. H 2D in the vertical direction VThe antenna spacing is arranged in a straight line along the right-downward direction.

[0742] In addition, the second receiving antenna group is offset to the left by 2D relative to the first receiving antenna group. H And offset downwards by D V Location configuration.

[0743] Here, the number of receiving antennas in the first receiving antenna group is set to "N". RxLowerRightGr1_ANT For example, N RxLowerRightGr1_ANT ≥2. Additionally, the number of receiving antennas in the second receiving antenna group is set to "N". RxLowerRightGr1_ANT For example, N RxLowerRightGr2_ANT ≧2.

[0744] Figure 76 N represents TxUpperRightGr1_ANT =4(Tx#2, Tx#4, Tx#6, Tx#8), N TxUpperRightGr2_ANT =4(Tx#1, Tx#3, Tx#5, Tx#7), N RxLowerRightGr1_ANT =2(Rx#4, Rx#3), N RxLowerRightGr2_ANT Examples of MIMO array configurations and virtual receiver array configurations with the condition of 2 (Rx#2, Rx#1).

[0745] Figure 77 N represents TxUpperRightGr1_ANT =2(Tx#2, Tx#4), N TxUpperRightGr2_ANT =2(Tx#1, Tx#3), N RxLowerRightGr1_ANT =3(Rx#2, Rx#4, Rx#6), N RxLowerRightGr2_ANT Example of MIMO array configuration and virtual receiver array configuration when (Rx#1, Rx#3, Rx#5) = 3.

[0746] Figure 78 N represents TxUpperRightGr1_ANT =4(Tx#2, Tx#4, Tx#6, Tx#8), N TxUpperRightGr2_ANT =4(Tx#1, Tx#3, Tx#5, Tx#7), N RxLowerRightGr1_ANT =3(Rx#2, Rx#4, Rx#6), N RxLowerRightGr2_ANT Examples of MIMO array configurations and virtual receiver array configurations with a range of 3 (Rx#1, Rx#3, Rx#5).

[0747] exist Figure 76 , Figure 77 and Figure 78 In the various MIMO array configurations shown, for example, D H and D VBy setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0748] Additionally, for example, in Figure 76 , Figure 77 and Figure 78 In the virtual receiver arrays shown, although some elements of each virtual array are arranged in overlapping positions, the angular resolution can be improved because the aperture length of the virtual receiver array can be increased. Furthermore, in Figure 76 and Figure 77 In this context, the virtual array elements are not repeated. Figure 78 In the middle, the virtual array element is repeated in two places.

[0749] In addition, it is possible to use D H D V Intervals, closely configured in Figure 76 , Figure 77 and Figure 78 The virtual array elements are shown near the center of each virtual receiver array. Additionally, as... Figure 76 , Figure 77 and Figure 78 As shown, near the center of each virtual receiver array, elements corresponding to certain coordinate positions are missing. However, radar device 10 uses a perimeter surrounding these missing positions with D... H D V The received signals of closely spaced virtual array elements are interpolated, thereby enabling the approximate reception of the received signal of the missing element.

[0750] In addition, closely configured in Figure 76 , Figure 77 and Figure 78 The number of virtual array elements near the center of each virtual receiver array shown will depend on N. TxUpperRightGr1_ANT N TxUpperRightGr2_ANT N RxLowerRightGr1_ANT N RxLowerRightGr2_ANT And increase.

[0751] For example, in a virtual receiver array, in the horizontal direction, 0.5×(N) TxUpperRightGr1_ANT +N TxUpperRightGr2_ANT +N RxLowerRightGr1_ANT +N RxLowerRightGr2_ANT ) - 1 virtual array element with D H Alternating arrangement, in the vertical direction, (N) TxUpperRightGr1_ANT +N TxUpperRightGr2_ANT +N RxLowerRightGr1_ANT +N RxLowerRightGr2_ANT ) - 5 virtual array elements in D V Arranged at intervals. In the virtual receiver array, with D...H D V The more closely spaced the virtual array elements are arranged, the better the effect of reducing grating lobes and side lobes will be.

[0752] In addition, N TxUpperRightGr1_ANT N TxUpperRightGr2_ANT N RxLowerRightGr1_ANT N RxLowerRightGr2_ANT The larger the aperture, the greater the number of virtual array elements arranged along the horizontal and vertical directions. Therefore, it is possible to increase the aperture length of the virtual receiving array in the horizontal and vertical directions, thereby improving the angular resolution in the horizontal and vertical directions.

[0753] Figure 79 For example, it means in such a way Figure 78 The diagram shows a MIMO array configuration using 8 transmit antennas 106 (Nt=8) and 6 receive antennas 202 (Na=6). TxUpperRightGr1_ANT =N TxUpperRightGr2_ANT =4, N RxLowerRightGr1_ANT =N RxLowerRightGr2_ANT =3,D H =0.5λ, D V In the case of λ = 0.5λ, an example of the direction estimation result is given when beamforming is used as the arrival direction estimation algorithm for the direction estimation unit 214. Furthermore, calculations were performed with the directivity of each antenna set to omnidirectional.

[0754] exist Figure 79 The output of the arrival direction estimation evaluation function value is plotted within the horizontal ±90 degree range and the vertical ±90 degree range when the target true value is set to 0 degrees horizontally and 0 degrees vertically.

[0755] exist Figure 79 In this process, it can be confirmed that in directions other than the horizontal and vertical 0 degrees of the target true value, such as with... Figure 1A Compared to this, the number of grid lobes is reduced. For example, in Figure 79 In the study, it was confirmed that the peak power ratio (PSLR) of the highest side lobe (excluding the main lobe) relative to the peak power ratio of the main lobe in the horizontal and vertical 0-degree directions is approximately 0.28, for example, compared to... Figure 69 The structure of basic configuration 4 shown (N) TxUpperRightGr1_ANT =N TxUpperRightGr2_ANT =N RxLowerRightGr1_ANT =N RxLowerRightGr2_ANT = (for example, refer to the case of =) Figure 71 Compared to, by increasing N TxUpperRightGr1_ANT N TxUpperRightGr2_ANT N RxLowerRightGr1_ANT N RxLowerRightGr2_ANT This improves the effect of reducing side lobes. Additionally, in Figure 79 In the middle, it is possible to confirm with Figure 71 In comparison, the peak of the main lobe also becomes sharper, by increasing N TxUpperRightGr1_ANT N TxUpperRightGr2_ANT N RxLowerRightGr1_ANT N RxLowerRightGr2_ANT Angular resolution is improved.

[0756] Furthermore, the more N increases TxUpperRightGr1_ANT N TxUpperRightGr2_ANT N RxLowerRightGr1_ANT N RxLowerRightGr2_ANT Compared to the horizontal direction, it can expand the aperture length of the virtual array in the vertical direction, thus making it a MIMO array structure that can more easily improve the angular resolution in the vertical direction compared to the angular resolution in the horizontal direction.

[0757] (Configuration Method 4-1C)

[0758] Configuration method 4-1C is a combination of configuration method 4-1A and configuration method 4-1B.

[0759] For example, the transmit array antenna consists of a first transmit antenna group and a second transmit antenna group. Furthermore, each transmit antenna group includes multiple transmit antenna elements, which are arranged in a 2D configuration in the horizontal direction. H D in the vertical direction V The antenna spacing is arranged in a straight line along the right-downward direction.

[0760] In addition, the second transmitting antenna group is offset to the left by D relative to the first transmitting antenna group. H And offset downwards by 2D V Location configuration.

[0761] Here, the number of transmitting antennas in the first transmitting antenna group is set to "N". TxLowerRightGr1_ANT For example, N TxLowerRightGr1_ANT ≥2. Additionally, the number of transmitting antennas in the second transmitting antenna group is set to "N". TxLowerRightGr2_ANT For example, N TxLowerRightGr2_ANT ≧2.

[0762] Additionally, for example, the receiving array antenna consists of a first receiving antenna group and a second receiving antenna group. Furthermore, each receiving antenna group includes multiple receiving antenna elements, which are arranged in a horizontal direction at a D-shape. H 2D in the vertical direction V The antenna spacing is arranged in a straight line along the right-downward direction.

[0763] In addition, the second receiving antenna group is offset to the left by 2D relative to the first receiving antenna group. H And offset downwards by D V Location configuration.

[0764] Here, the number of receiving antennas in the first receiving antenna group is set to "N". RxLowerRightGr1_ANT For example, N RxLowerRightGr1_ANT ≥2. Additionally, the number of receiving antennas in the second receiving antenna group is set to "N". RxLowerRightGr2_ANT For example, N RxLowerRightGr2_ANT ≧2.

[0765] Figure 80 N represents TxLowerRightGr1_ANT =4(Tx#2, Tx#4, Tx#6, Tx#8), N TxLowerRightGr2_ANT =4(Tx#1, Tx#3, Tx#5, Tx#7), N RxLowerRightGr1_ANT =4(Rx#2, Rx#4, Rx#6, Rx#8), N RxLowerRightGr2_ANT Examples of MIMO array configurations and virtual receiver array configurations with a range of 4 (Rx#1, Rx#3, Rx#5, Rx#7).

[0766] exist Figure 80 In the MIMO array configuration shown, for example, D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0767] In addition, Figure 80 In the virtual receiver array shown, although some elements of each virtual array element are arranged in overlapping positions, the angular resolution can be improved because the aperture length of the virtual receiver array can be increased. Furthermore, in Figure 80 In this context, the virtual array elements are repeated in one place.

[0768] In addition, it is possible to use D H D V Intervals, closely configured in Figure 80 The virtual array elements shown are located near the center of the virtual receiver array. Furthermore, as... Figure 80 As shown, near the center of each virtual receiver array, elements corresponding to certain coordinate positions are missing. However, radar device 10 uses a perimeter surrounding these missing positions with D... H D V The received signals of closely spaced virtual array elements are interpolated, thereby enabling the approximate reception of the received signal of the missing element.

[0769] In addition, closely configured in Figure 80 The number of virtual array elements near the center of each virtual receiver array shown will depend on N. TxLowerRightGr1_ANT N TxLowerRightGr2_ANT N RxLowerRightGr1_ANT NRxLowerRightGr2_ANT And increase.

[0770] For example, in a virtual receiver array, in the horizontal direction, 0.5×(N) TxLowerRightGr1_ANT +N TxLowerRightGr2_ANT +N RxLowerRightGr1_ANT +N RxLowerRightGr2_ANT )+1 virtual array elements in D H Arranged at intervals, in the vertical direction, 0.5×(N) TxLowerRightGr1_ANT +N TxLowerRightGr2_ANT +N RxLowerRightGr1_ANT +N RxLowerRightGr2_ANT )+1 virtual array elements in D V Arranged at intervals. In the virtual receiver array, with D... H D V The more closely spaced the virtual array elements are arranged, the better the effect of reducing grating lobes and side lobes will be.

[0771] In addition, N TxLowerRightGr1_ANT N TxLowerRightGr2_ANT N RxLowerRightGr1_ANT N RxLowerRightGr2_ANT The larger the aperture, the greater the number of virtual array elements arranged along the horizontal and vertical directions. Therefore, it is possible to increase the aperture length of the virtual receiving array in the horizontal and vertical directions, thereby improving the angular resolution in the horizontal and vertical directions.

[0772] (Configuration Method 4-1D)

[0773] Configuration method 4-1D is a combination of configuration method 4-1A and configuration method 4-1B.

[0774] For example, the transmit array antenna consists of a first transmit antenna group and a second transmit antenna group. Furthermore, each transmit antenna group includes multiple transmit antenna elements, which are arranged in a 2D configuration in the horizontal direction. H D in the vertical direction V The antenna spacing is arranged in a straight line along the upper right direction.

[0775] In addition, the second transmitting antenna group is offset to the right by 2D relative to the first transmitting antenna group. H And offset downwards by D V Location configuration.

[0776] Here, the number of transmitting antennas in the first transmitting antenna group is set to "N". TxUpperRightGr1_ANT For example, N TxUpperRightGr1_ANT ≥2. Additionally, the number of transmitting antennas in the second transmitting antenna group is set to "N". TxUpperRightGr2_ANT For example, N TxUpperRightGr2_ANT ≧2.

[0777] Additionally, for example, the receiving array antenna consists of a first receiving antenna group and a second receiving antenna group. Furthermore, each receiving antenna group includes multiple receiving antenna elements, which are arranged in a 2D configuration in the horizontal direction. H D in the vertical direction V The antenna spacing is arranged in a straight line along the upper right direction.

[0778] In addition, the second receiving antenna group is offset to the right by D relative to the first receiving antenna group. H And offset downwards by 2D V Location configuration.

[0779] Here, the number of receiving antennas in the first receiving antenna group is set to "N". RxUpperRightGr1_ANT For example, N RxUpperRightGr1_ANT ≥2. Additionally, the number of receiving antennas in the second receiving antenna group is set to "N". RxUpperRightGr2_ANT For example, N RxUpperRightGr2_ANT ≧2.

[0780] Figure 81 N represents TxUpperRightGr1_ANT =4(Tx#2, Tx#4, Tx#6, Tx#8), N TxUpperRightGr2_ANT =4(Tx#1, Tx#3, Tx#5, Tx#7), N RxUpperRightGr1_ANT =4(Rx#2, Rx#4, Rx#6, Rx#8), N RxLUpperRightGr2_ANT Examples of MIMO array configurations and virtual receiver array configurations with a range of 4 (Rx#1, Rx#3, Rx#5, Rx#7).

[0781] exist Figure 81 In the MIMO array configuration shown, for example, D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0782] In addition, Figure 81 In the virtual receiver array shown, although some elements of each virtual array element are arranged in overlapping positions, the angular resolution can be improved because the aperture length of the virtual receiver array can be increased. Furthermore, in Figure 81 In this context, the virtual array elements are repeated in one place.

[0783] In addition, it is possible to use D H D V Intervals, closely configured in Figure 81 The virtual array elements shown are located near the center of the virtual receiver array. Furthermore, as... Figure 81As shown, near the center of each virtual receiver array, elements corresponding to certain coordinate positions are missing. However, radar device 10 uses a perimeter surrounding these missing positions with D... H D V The received signals of closely spaced virtual array elements are interpolated, thereby enabling the approximate reception of the received signal of the missing element.

[0784] In addition, closely configured in Figure 81 The number of virtual array elements near the center of each virtual receiver array shown will depend on N. TxUpperRightGr1_ANT N TxLUpperRightGr2_ANT N RxUpperRightGr1_ANT N RxUpperRightGr2_ANT And increase.

[0785] For example, in a virtual receiver array, in the horizontal direction, 0.5×(N) TxUpperRightGr1_ANT +N TxUpperRightGr2_ANT +N RxUpperRightGr1_ANT +N RxUpperRightGr2_ANT )+1 virtual array elements in D H Arranged at intervals, in the vertical direction, 0.5×(N) TxUpperRightGr1_ANT +N TxUpperRightGr2_ANT +N RxUpperRightGr1_ANT +N RxUpperRightGr2_ANT ) virtual array elements in D V Arranged at intervals. In the virtual receiver array, with D... H D V The more closely spaced the virtual array elements are arranged, the better the effect of reducing grating lobes and side lobes will be.

[0786] In addition, N TxUpperRightGr1_ANT N TxUpperRightGr2_ANT N RxUpperRightGr1_ANT N RxUpperRightGr2_ANT The larger the aperture, the greater the number of virtual array elements arranged along the horizontal and vertical directions. Therefore, it is possible to increase the aperture length of the virtual receiving array in the horizontal and vertical directions, thereby improving the angular resolution in the horizontal and vertical directions.

[0787] The above describes the antenna configuration methods 4-1A, 4-1B, 4-1C and 4-1D in Variation 1 of Basic Configuration 4.

[0788] Furthermore, configuration methods 4-1A, 4-1B, 4-1C, and 4-1D describe the case where the transmitting array antenna consists of a first transmitting antenna group and a second transmitting antenna group. However, the number N of transmitting antenna groups contained in the transmitting array antenna could also be [missing information]. TxGroupThe structure has 3 or more elements. In this case, the ntx-th transmit antenna group is configured relative to the (ntx-1)-th transmit antenna group according to any one of the following rules: configuration method 4-1A, configuration method 4-1B, configuration method 4-1C, and configuration method 4-1D. Here, ntx = 1, ..., N TxGroup .

[0789] Similarly, configuration methods 4-1A, 4-1B, 4-1C, and 4-1D describe the case where the receiving array antenna consists of a first receiving antenna group and a second receiving antenna group. However, the number of receiving antenna groups could also be N. RxGroup The structure has 3 or more elements. In this case, the nrx-th receiving antenna group is configured relative to the (nrx-1)-th receiving antenna group according to any one of the following rules: configuration method 4-1A, configuration method 4-1B, configuration method 4-1C, and configuration method 4-1D. Here, nrx = 1, ..., N RxGroup .

[0790] As an example, Figure 82 In configuration method 4-1B, N represents the number of transmitting antenna groups. TxGroup =3. Number of receiving antenna groups N RxGroup =3, and N TxUpperRightGr1_ANT =3(Tx#3, Tx#6, Tx#9), N TxUpperRightGr2_ANT =3(Tx#2, Tx#5, Tx#8), N TxUpperRightGr3_ANT =3(Tx#1, Tx#4, Tx#7), N RxLowerRightGr1_ANT =3(Rx#7, Rx#8, Rx#9), N RxLowerRightGr2_ANT =3(Rx#4, Rx#5, Rx#6), N RxLowerRightGr3_ANT Examples of MIMO array configurations and virtual receiver array configurations with the following parameters: =3 (Rx#1, Rx#2, Rx#3).

[0791] For example, in Figure 82 In the MIMO array configuration shown, D H and D V By setting it to approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0792] In addition, Figure 82 In the virtual receiver array shown, although some elements of each virtual array element are arranged in overlapping positions, the angular resolution can be improved because the aperture length of the virtual receiver array can be increased. Furthermore, in Figure 82 In the image, the virtual array element is repeated in eight places.

[0793] In addition, it is possible to use D H D V Intervals, closely configured in Figure 82 The virtual array elements shown are located near the center of the virtual receiver array. Furthermore, as... Figure 82 As shown, near the center of the virtual receiving array, elements corresponding to a portion of the coordinates are missing. However, radar device 10 uses a perimeter surrounding this missing location with a D-type array. H D V The received signals of closely spaced virtual array elements are interpolated, thereby enabling the approximate reception of the received signal of the missing element.

[0794] In addition, closely configured in Figure 82 The number of virtual array elements near the center of each virtual receiver array shown will depend on N. TxGroup N RxGroup And increase.

[0795] <Example 2 of the basic configuration 4>

[0796] In Variation 2 of Basic Configuration 4, a MIMO array configuration is described, in which the configuration of the transmit array antenna of the four elements shown in Basic Configuration 4 and the configuration of the receive array antenna of the four elements are respectively set as "basic sets", and the configuration positions of the multiple basic sets are shifted.

[0797] Furthermore, in the configuration shown below, it is possible to eliminate duplicate elements in the virtual receiver array configuration and to allow more virtual array elements to be arranged in D... V Or D H The arrangement of closely spaced virtual receiver arrays near the center involves setting offsets in the horizontal and vertical directions relative to the basic set of transmit array antennas, or offsets in the horizontal and vertical directions relative to the basic set of receive array antennas. However, this is not a limitation; for example, this can also be achieved by adjusting the offsets in the arrangement of virtual receiver arrays, either by adding unequal spacing or by adding repetitive virtual array elements.

[0798] Figure 83 This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =2, and set the number of basic sets of receiving array antennas to N. RxBaseSet Examples of MIMO array configurations with MIMO = 1 and virtual receiver array configurations. Figure 83In this context, the horizontal offset of the second basic set (e.g., Tx#5, Tx#6, Tx#7, and Tx#8) relative to the first basic set (e.g., Tx#1, Tx#2, Tx#3, and Tx#4) is set as D. Hoffset_TxBaseSet2 =5D H Set the offset of the configuration position in the vertical direction to D. Voffset_TxBaseSet2 =0. For example... Figure 83 As shown, based on the configuration that shifts the two basic sets of the transmitting array antennas along the horizontal direction, it is possible to increase the horizontal direction by D H The number of closely spaced virtual array elements enables improved angular resolution in the horizontal direction.

[0799] Figure 84 This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =2, and set the number of basic sets of receiving array antennas to N. RxBaseSet Examples of MIMO array configurations with MIMO = 1 and virtual receiver array configurations. Figure 84 In this context, the horizontal offset of the second basic set (Tx#5, Tx#6, Tx#7, Tx#8) relative to the first basic set (e.g., Tx#1, Tx#2, Tx#3, and Tx#4) is set as D. Hoffset_TxBaseSet2 =0, set the vertical offset of the configuration position to D. Voffset_TxBaseSet2 =5D V .like Figure 84 As shown, based on the configuration of offsetting the two basic sets of the transmitting array antenna along the vertical direction, it is possible to increase the vertical direction by D V The number of closely spaced virtual array elements enables improved angular resolution in the horizontal direction.

[0800] Figure 85 This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =1, and set the number of basic sets of receiving array antennas to N. RxBaseSet Examples of MIMO array configurations with a value of 2, and examples of virtual receiver array configurations. Figure 85 In this context, the horizontal offset of the second basic set (Rx#5, Rx#6, Rx#7, Rx#8) relative to the first basic set (e.g., Rx#1, Rx#2, Rx#3, and Rx#4) is set to D. Hoffset_RxBaseSet2 =5D H Set the offset of the configuration position in the vertical direction to D. Voffset_RxBaseSet2 =0. For example... Figure 85As shown, based on the configuration that shifts the two basic sets of the receiving array antennas along the horizontal direction, it is possible to increase the horizontal direction by D H The number of closely spaced virtual array elements enables improved angular resolution in the horizontal direction.

[0801] Figure 86 This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =1, and set the number of basic sets of receiving array antennas to N. RxBaseSet Examples of MIMO array configurations with a value of 2, and examples of virtual receiver array configurations. Figure 86 In this context, the horizontal offset of the second basic set (Rx#5, Rx#6, Rx#7, Rx#8) relative to the first basic set (e.g., Rx#1, Rx#2, Rx#3, and Rx#4) is set to D. Hoffset_RxBaseSet2 =0, set the vertical offset of the configuration position to D. Voffset_RxBaseSet2 =5D V .like Figure 86 As shown, based on the configuration of offsetting the two basic sets of the receiving array antenna along the vertical direction, it is possible to increase the vertical direction by D V The number of closely spaced virtual array elements enables improved angular resolution in the vertical direction.

[0802] Figure 87 This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =2, and set the number of basic sets of receiving array antennas to N. RxBaseSet Examples of MIMO array configurations with a value of 2, and examples of virtual receiver array configurations. Figure 87 In this context, the horizontal offset of the second basic set (Tx#5, Tx#6, Tx#7, Tx#8) of the transmit array antennas relative to the first basic set (e.g., Tx#1, Tx#2, Tx#3, and Tx#4) is set as D. Hoffset_TxBaseSet2 =8D H Set the offset of the configuration position in the vertical direction to D. Voffset_TxBaseSet2 =0. Additionally, in Figure 87 In this context, the horizontal offset of the second basic set (Rx#5, Rx#6, Rx#7, Rx#8) of the receiving array antennas relative to the first basic set (e.g., Rx#1, Rx#2, Rx#3, and Rx#4) is set as D. Hoffset_RxBaseSet2 =5D H Set the offset of the configuration position in the vertical direction to D. Voffset_RxBaseSet2 =0. For example... Figure 87As shown, based on the configuration of the two basic sets of the transmitting array antenna offset along the horizontal direction, and the configuration of the two basic sets of the receiving array antenna offset along the horizontal direction, for example, with... Figure 83 or Figure 85 In comparison, it can further increase along the horizontal direction with D H The number of closely spaced virtual array elements allows for further improvement in angular resolution in the horizontal direction.

[0803] Figure 88A This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =4, and set the number of basic sets of receiving array antennas to N. RxBaseSet Example of MIMO array configuration with 4 = 4 Figure 88B This represents a virtual receiver array configuration example.

[0804] exist Figure 88A In this context, the horizontal offset of the second basic set (Tx#5, Tx#6, Tx#7, Tx#8) of the transmit array antennas relative to the first basic set (e.g., Tx#1, Tx#2, Tx#3, and Tx#4) is set as D. Hoffset_TxBaseSet2 =8D H Set the offset of the configuration position in the vertical direction to D. Voffset_TxBaseSet2 =0, set the horizontal offset of the configuration position of the third basic set (Tx#9, Tx#10, Tx#11, Tx#12) to D. Hoffset_TxBaseSet3 =0, set the vertical offset of the configuration position to D. Voffset_TxBaseSet3 =5D V Set the horizontal offset of the configuration position of the fourth basic set (Tx#13, Tx#14, Tx#15, Tx#16) to D. Hoffset_TxBaseSet4 =8D H And set the offset of the configuration position in the vertical direction to D. Voffset_TxBaseSet4 =5D V .

[0805] In addition, Figure 88A In this context, the horizontal offset of the second basic set (Rx#5, Rx#6, Rx#7, Rx#8) of the receiving array antennas relative to the first basic set (e.g., Rx#1, Rx#2, Rx#3, and Rx#4) is set as D. Hoffset_RxBaseSet2 =5D H Set the offset of the configuration position in the vertical direction to D. Voffset_RxBaseSet2 =0, set the horizontal offset of the configuration position of the third basic set (Rx#9, Rx#10, Rx#11, Rx#12) to D. Hoffset_RxBaseSet3=0, set the vertical offset of the configuration position to D. Voffset_RxBaseSet3 =8D V Set the horizontal offset of the configuration position of the fourth basic set (Rx#13, Rx#14, Rx#15, Rx#16) to D. Hoffset_RxBaseSet4 =5D H And set the offset of the configuration position in the vertical direction to D. Voffset_RxBaseSet4 =8D V .

[0806] like Figure 88A and Figure 88B As shown, based on the configuration after shifting the basic set of transmitting array antennas along the horizontal direction, and the configuration after shifting the basic set of receiving array antennas along the horizontal direction, for example, with... Figure 83 or Figure 85 In comparison, it can further increase along the horizontal direction with D H The number of closely spaced virtual array elements further improves the angular resolution in the horizontal direction. (Furthermore, in the case of Figure 88, the virtual array elements are repeated in eight places.)

[0807] Similarly, as Figure 88A and Figure 88B As shown, based on the configuration after shifting the basic set of transmitting array antennas along the vertical direction, and the configuration after shifting the basic set of receiving array antennas along the vertical direction, for example, with... Figure 84 or Figure 86 In comparison, it can further increase along the vertical direction with D V The number of closely spaced virtual array elements allows for further improvement in angular resolution in the vertical direction.

[0808] Furthermore, in Variation 2, the case where the antenna configuration of the basic configuration 4 is set as the basic set is described, but the basic set is not limited to the antenna configuration of the basic configuration 4, and may also be the antenna configuration of Variation 1 of the basic configuration 4.

[0809] In addition, the number of basic sets (N) contained in the transmitting array antenna and the receiving array antenna TxBaseSet N RxBaseSet () is not limited to the examples above and can also be other values.

[0810] <Basic Configuration 5>

[0811] Figure 89 Examples of configurations for the transmitting antenna 106 and receiving antenna 202 in basic configuration 5, and examples of configurations for the virtual receiving array.

[0812] (1) Configuration of transceiver antennas

[0813] exist Figure 89 In the transmitting array antenna, the number of transmitting antennas 106 is Nt = 4 (Tx#1, Tx#2, Tx#3 and Tx#4), and the number of receiving antennas 202 is Na = 4 (Rx#1, Rx#2, Rx#3 and Rx#4).

[0814] Figure 89 The transmitted array antenna shown is, for example, composed of a "first transmitted antenna group" ( Figure 89 Tx#2, Tx#4) and "second transmitting antenna group" ( Figure 89 The antennas consist of Tx#1 and Tx#3. Each transmitting antenna group contains two transmitting antenna elements, with a horizontal antenna spacing of D between them. H The antenna spacing in the vertical direction is D. V . Figure 89 The adjacent transmitting antennas of each of the shown transmitting antenna groups are separated by D in the horizontal direction. H They are arranged at intervals and separated by D in the vertical direction. V They are configured at intervals. In other words, in Figure 89 In the diagram, each transmitting antenna group contains transmitting antennas arranged in a horizontal direction with a diameter of D. H D in the vertical direction V The antenna spacing is arranged in a straight line along the right-downward direction (in other words, the left-upward direction).

[0815] In addition, Figure 89 In the middle, relative to the first transmitting antenna group, the second transmitting antenna group is offset 2D to the left in the horizontal direction. H And offset downwards in the vertical direction by D V Location configuration. In other words, Figure 89 The adjacent transmitting antenna groups shown are offset by 2D along the horizontal direction. H The interval (in other words, D) H (twice the interval), and offset by D in the vertical direction. V The relationship.

[0816] In addition, Figure 89 In the middle, relative to the first transmitting antenna group, the second transmitting antenna group is offset to the left in the horizontal direction by D. H And offset 2D vertically downwards. V Location configuration.

[0817] in addition, Figure 89 The received array antenna shown is, for example, composed of a "first received antenna group" ( Figure 89 Rx#2, Rx#4) and "second receiving antenna group" ( Figure 89The antennas are composed of Rx#1 and Rx#3. Each receiving antenna group contains two receiving antenna elements, and the horizontal spacing between these two receiving antenna elements is D. H The antenna spacing in the vertical direction is D. V . Figure 89 The adjacent receiving antennas of each of the shown receiving antenna groups are spaced D apart in the horizontal direction. H They are arranged at intervals and separated by D in the vertical direction. V They are configured at intervals. In other words, in Figure 89 In the diagram, each receiving antenna group contains transmitting antennas arranged in a horizontal direction with an angle of D. H D in the vertical direction V The antenna spacing is arranged in a straight line along the right-upward direction (in other words, the left-downward direction).

[0818] In addition, Figure 89 In the middle, relative to the first receiving antenna group, the second receiving antenna group is offset 2D to the right in the horizontal direction. H And offset downwards in the vertical direction by D V Location configuration. In other words, Figure 89 The adjacent receiving antenna groups shown are offset by 2D along the horizontal direction. H The interval (in other words, D) H (twice the interval), and offset by D in the vertical direction. V The relationship.

[0819] Additionally, for example, such as Figure 89 As shown, transmitting antennas Tx#1 to Tx#4 are each configured at different positions in the horizontal direction. Similarly, as... Figure 89 As shown, receiving antennas Rx#1 to Rx#4 are each configured at different positions in the horizontal direction.

[0820] In addition, Figure 89 In the transmit and receive antenna configuration shown, the respective positions of the transmit antennas and the respective positions of the receive antennas are, for example, linearly symmetrical about a line parallel to the horizontal or vertical direction (in other words, reversed).

[0821] For example, suppose Figure 89 The horizontal direction shown corresponds to the X-axis. Figure 89 The vertical direction shown corresponds to the Y-axis direction.

[0822] For example, in Figure 89 In the case of the antenna configuration shown, the position coordinates of the transmitting antenna 106 constituting the transmitting array antenna are the same as the position coordinates of the transmitting antenna Tx#1 (X). T_#1 YT_#1 Based on the reference, the position coordinates (X) of the transmitting antenna Tx#2 are represented as follows. T_#2 Y T_#2 )=(X T_#1 +2D H Y T_#1 +D V ), the position coordinates (X) of transmitting antenna Tx#3 T_#3 Y T_#3 )=(X T_#1 +D H Y T_#1 -D V ), the position coordinates (X) of transmitting antenna Tx#4 T_#4 Y T_#4 )=(X T_#1 +3D H Y T_#1 ).

[0823] Similarly, the position coordinates of the receiving antenna 202 constituting the receiving array antenna are the same as the position coordinates of the receiving antenna Rx#1 (X R_#1 Y R_#1 Based on the reference, the position coordinates (X) of the receiving antenna Rx#2 are represented as follows. R_#2 Y R_#2 )=(X R_#1 -2D H Y R_#1 +D V ), the position coordinates (X) of receiving antenna Rx#3 R_#3 Y R_#3 )=(X R_#1 +D H Y R_#1 +D V ), the position coordinates of receiving antenna Rx#4 (X R_#4 Y R_#4 )=(X R_#1 -D H Y R_#1 +2D V ).

[0824] (2) Configuration of the virtual receiver array

[0825] According to the above Figure 89 The configuration of the virtual receiving array (virtual antenna VA#1 to virtual antenna VA#16) formed by the transmitting and receiving antenna configuration shown has the following characteristics.

[0826] For example, according to Figure 89 The configuration of the transmitting array antenna and the receiving array antenna are shown, along with the position coordinates (X, Y, F) of the virtual receiving arrays VA#1 to VA#16. V_#1 YV_#1 )~(X V_#16 Y V_#16 The details are as follows. Furthermore, VA#1 is represented here as the location reference (0, 0) of the virtual receiving array.

[0827] (0, 0), (2D) H D V ), (D H -D V ), (3D) H ,0),(-2D H D V (0, 2D) V ), (-D H ,0),(D H D V ), (D H D V ), (3D) H 2D V (2D) H ,0),(4D H D V ), (-D H 2D V ), (D H 3D V (0, D) V (2D) H 2D V )

[0828] Thus, in Figure 89 In the configuration of the virtual receiver array shown, except for a portion of the virtual array elements (e.g., VA#8, VA#9), each virtual receiver array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, resulting in a narrower main lobe and thus improved angular resolution.

[0829] Additionally, located Figure 89 The virtual array elements VA#4, VA#11, VA#2, VA#16, VA#10, VA#7, VA#1, VA#15, VA#6, VA#13, VA#8, and VA#9 near the center of the virtual receiving array shown are arranged horizontally along the direction of D. H The spacing is closely arranged, and along the vertical direction at D V The spacing is closely spaced. As an example, in... Figure 89 In the middle, the interval D H and interval D VWith a value set to approximately 0.5λ, the virtual array elements VA#4, VA#11, VA#2, VA#16, VA#10, VA#7, VA#1, VA#15, VA#6, VA#13, VA#8, and VA#9 are arranged horizontally with a distance of D. H =0.5λ interval configuration, and along the vertical direction with D V =0.5λ interval configuration. Therefore, compared with basic configuration 1 (for example, refer to...) Figure 8 Similarly, it can reduce the number of grid lobes.

[0830] In addition, Figure 89 Near the center of the virtual receiving array shown, there is a lack of [something] with interval D. H and interval D V The elements at coordinates corresponding to the positions are surrounded by closely arranged virtual array elements. However, radar device 10, for example, uses elements spaced D to surround the missing parts. H and interval D V The received signals of the closely arranged virtual array elements are interpolated, thereby enabling the received signals of the elements in the missing part to be received approximately.

[0831] Additionally, for example, in Figure 89 In the MIMO array configuration shown, the interval D H and interval D V With a value of approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be greater than 1λ.

[0832] Therefore, as long as the transverse direction W of the transmitting antenna 106 and the receiving antenna 202 is... ANT The component size is smaller than D H This allows the use of antennas of arbitrary size in the longitudinal direction. For example, it enables the application of antennas such as... Figure 25A The antenna shown is as Figure 89 The antennas of at least one of the transmitting array antennas and receiving array antennas shown are as follows: Figure 25A The antenna shown uses eight elements as a subarray, consisting of a planar patch antenna with eight elements arranged vertically and a planar patch antenna with one element arranged horizontally.

[0833] Furthermore, the number of transmitting antennas contained in the first transmitting antenna group (hereinafter referred to as "N") TxGroup1_ANT The number of transmitting antennas contained in the second transmitting direction antenna group (hereinafter, denoted as "N") TxGroup2_ANT The numbers can be the same or differ by one antenna. For example, |N TxGroup1_ANT -N TxGroup2_ANT | = 0 or 1.

[0834] Similarly, the number of receiving antennas contained in the first receiving antenna group (hereinafter denoted as "N") RxGroup1_ANT The number of receiving antennas in the second receiving antenna group (hereinafter, denoted as "N"), and the number of receiving antennas in the second receiving antenna group. RxGroup2_ANT The numbers can be the same or differ by one antenna. For example, |N RxGroup1_ANT -N RxGroup2_ANT | = 0 or 1.

[0835] Figure 90A and Figure 90B N represents the number of transmitting antennas in the first transmitting antenna group. TxGroup1_ANT The number of transmitting antennas N in the second transmitting antenna group TxGroup2_ANT The first receiving antenna group contains N receiving antennas, which differ by one antenna. RxGroup1_ANT The number of receiving antennas N in the second receiving antenna group RxGroup2_ANT Examples of MIMO array configurations with the same number of units, and examples of virtual receiver array configurations.

[0836] like Figure 90A and Figure 90B As shown, |N TxGroup1_ANT -N TxGroup2_ANT |=1 and|N RxGroup1_ANT -N RxGroup2_ANT When |=0, the MIMO array configuration is 3 transmit antennas and 4 receive antennas (N). RxGroup1_ANT =N RxGroup2_ANT =2) structure, for example, there are two patterns.

[0837] Figure 90A It is N TxGroup1_ANT =1(Tx#2), N TxGroup2_ANT Example of MIMO array configuration with 2 (Tx#1, Tx#3) Figure 90B It is N TxGroup1_ANT =2(Tx#2, Tx#3), N TxGroup2_ANT Example of MIMO array configuration with =1 (Tx#1).

[0838] then, Figure 91A and Figure 91B N represents the number of transmitting antennas in the first transmitting antenna group. TxGroup1_ANT The number of transmitting antennas N in the second transmitting antenna group TxGroup2_ANT The number of receiving antennas N is the same, and the first receiving antenna group contains the same number of receiving antennas. RxGroup1_ANT The number of receiving antennas N in the second receiving antenna group RxGroup2_ANT Examples of MIMO array configurations with a difference of one antenna and examples of virtual receiver array configurations.

[0839] like Figure 91A and Figure 91B As shown, |N TxGroup1_ANT -N TxGroup2_ANT |=0 and|N RxGroup1_ANT -N RxGroup2_ANT The MIMO array configuration with |=1 is a transmit antenna configuration of 4 (N) TxGroup1_ANT =N TxGroup2_ANT =2), a structure with 3 receiving antennas, for example, there are two modes.

[0840] Figure 91A It is N RxGroup1_ANT =1(Rx#3), N RxGroup2_ANT Example of MIMO array configuration with 2 (Rx#1, Rx#2) Figure 91B It is N RxGroup1_ANT =2(Rx#2, Rx#3), N RxGroup2_ANT Example of MIMO array configuration with =1 (Rx#1).

[0841] then, Figures 92A-92D N represents the number of transmitting antennas in the first transmitting antenna group. TxGroup1_ANT The number of transmitting antennas N in the second transmitting antenna group TxHGroup2_ANT The first receiving antenna group contains N receiving antennas, which differ by one antenna. RxGroup1_ANT The number of receiving antennas N in the second receiving antenna group RxGroup2_ANT Examples of MIMO array configurations with a difference of one antenna and examples of virtual receiver array configurations.

[0842] like Figures 92A-92D As shown, |N TxGroup1_ANT -N TxGroup2_ANT |=1 and|N RxGroup1_ANT -N RxGroup2_ANT When |=1, the MIMO array configuration is a structure with 3 transmit antennas and 3 receive antennas, for example, there exists Figures 92A-92D The four modes.

[0843] Figure 92A It is N TxVGroup1_ANT =1(Tx#2), N TxVGroup2_ANT =2(Tx#1, Tx#3), N RxHGroup1_ANT =1(Rx#3), N RxHGroup2_ANT Example of MIMO array configuration with =2 (Rx#1, Rx#2).

[0844] Figure 92B It is N TxVGroup1_ANT =1(Tx#2), N TxVGroup2_ANT =2(Tx#1, Tx#3), N RxHGroup1_ANT =2(Rx#2, Rx#3), N RxHGroup2_ANTExample of MIMO array configuration with =1 (Rx#1).

[0845] Figure 92C It is N TxVGroup1_ANT =2(Tx#2, Tx#3), N TxVGroup2_ANT =1(Tx#1), ​​N RxHGroup1_ANT =1(Rx#3), N RxHGroup2_ANT Example of MIMO array configuration with =2 (Rx#1, Rx#2).

[0846] Figure 92D It is N TxVGroup1_ANT =2(Tx#2, Tx#3), N TxVGroup2_ANT =1(Tx#1), ​​N RxHGroup1_ANT =2(Rx#2, Rx#3), N RxHGroup2_ANT Example of MIMO array configuration with =1 (Rx#1).

[0847] exist Figure 90A , Figure 90B , Figure 91A , Figure 91B and Figures 92A-92D In the virtual receiver array shown, each virtual array element is arranged in a different position without repetition. Therefore, the aperture length of the virtual receiver array can be increased, thereby improving the angular resolution.

[0848] Additionally, the virtual array elements located near the center of the virtual receiver array are in D H D V The spacing is closely spaced. As an example, in... Figure 90A , Figure 90B , Figure 91A , Figure 91B and Figures 92A-92D In the middle, the interval D H and interval D V With a value of approximately 0.5λ, the virtual array elements located near the center of the virtual receiver array move horizontally along the direction of D. H =0.5λ interval configuration, and along the vertical direction with D V A spacing configuration of 0.5λ is used. This reduces the number of grid lobes.

[0849] Additionally, for example, in the MIMO array configuration of basic configuration 5, the interval D is... H and interval D V With a value of approximately 0.5λ, the horizontal and vertical component dimensions of the transmitting antenna 106 and the receiving antenna 202 can be designed to be approximately 1λ or larger.

[0850] Therefore, for example, as long as the transverse direction W of the transmitting antenna 106 and the receiving antenna 202 is...ANT The component size is smaller than D H This allows the use of antennas of arbitrary size in the longitudinal direction. For example, Figure 93A Indicates to Figure 89 The antenna configuration shown applies Figure 25A The example shown is a subarray consisting of a planar patch antenna with eight elements arranged vertically and a planar patch antenna with one element arranged horizontally. Furthermore, as... Figure 93B As shown, except Figure 93A In addition to the transmit array antennas shown, non-powered components (dummy components) can also be configured. By using non-powered components, the effects of inter-antenna coupling caused by adjacent antennas can be uniformized, thereby enabling uniformity of the pointing characteristics of each transmit antenna (Tx#1~Tx#4).

[0851] Thus, by using an antenna with a subarray structure in the antenna configuration of basic configuration 5, the directional gain of the antenna can be improved, thereby improving the detection performance (e.g., detection range) of the radar device 10.

[0852] The direction estimation unit 214 uses the received signal from the virtual receiving array obtained according to the above-described transceiver antenna configuration to perform direction estimation processing in the horizontal and vertical directions. Furthermore, the processing of the virtual receiving array in the direction estimation unit 214 for basic configuration 5 is the same as that for basic configuration 1, therefore, its description is omitted here.

[0853] Figure 94 For example, in such Figure 89 The diagram shows a MIMO array configuration using 4 transmit antennas 106 (Nt=4) and 4 receive antennas 202 (Na=4). H =0.5λ, D V An example of the direction estimation result when beamforming is used as the arrival direction estimation algorithm for the direction estimation unit 214, where λ = 0.5λ. That is, in Figure 94 In this design, the horizontal and vertical antenna spacing of the transmitting antenna 106 is 1λ or more, and the horizontal and vertical antenna spacing of the receiving antenna 202 is also 1λ or more. Furthermore, the directivity of each antenna was set to omnidirectional, and calculations were performed.

[0854] exist Figure 94 The output of the arrival direction estimation evaluation function value is plotted within the horizontal ±90 degree range and the vertical ±90 degree range when the target true value is set to 0 degrees horizontally and 0 degrees vertically.

[0855] exist Figure 94 In this process, it can be confirmed that in directions other than the horizontal and vertical 0 degrees of the target true value, such as with... Figure 1A Compared to this, the number of grid lobes is reduced. For example, in Figure 94 In the meantime, the ratio of the peak power of the highest sidelobe (excluding the main lobe) in directions other than 0 degrees horizontally and vertically to the peak power of the main lobe in directions other than 0 degrees horizontally and vertically (PSLR) is about 0.35.

[0856] As described above, by using the MIMO array configuration of basic configuration 5, even if the element size in the longitudinal or transverse direction of the antennas used as the transmit and receive array antennas is about 1λ, the horizontal and vertical antenna spacing in the virtual receive array can be configured with an element spacing of about 0.5λ, thereby reducing grating lobes. Furthermore, for example, Figure 52A The virtual array elements of the virtual receiver array shown are configured without repetition, thus enabling an increase in the aperture length of the virtual receiver array and thereby improving angular resolution.

[0857] <Example 1 of the variation of basic configuration 5>

[0858] In Variation 1 of Basic Configuration 5, a MIMO array configuration is described, in which the configuration of the transmit array antenna and the configuration of the receive array antenna shown in Basic Configuration 5 are respectively set as "basic sets", and the configuration positions of multiple basic sets are shifted.

[0859] The following describes configuration methods 5-1A, 5-1B, and 5-1C of the variation 1 of basic configuration 5.

[0860] (Configuration Method 5-1A)

[0861] In configuration method 5-1A, it is explained that the configuration of the transmit array antenna of the four elements shown in basic configuration 5 and the configuration of the receive array antenna of the four elements are respectively set as "basic sets", and the configuration positions of multiple basic sets are offset to form a MIMO array configuration.

[0862] Furthermore, the configuration shown below allows for the elimination of duplicate elements in the virtual receiver array configuration, and enables more virtual array elements to be arranged in D... V Or D H The arrangement of closely spaced virtual receiver arrays near the center involves setting offsets in the horizontal and vertical directions relative to the basic set of transmit array antennas, or offsets in the horizontal and vertical directions relative to the basic set of receive array antennas. However, this is not a limitation; for example, this can also be achieved by adjusting the offsets in the arrangement of virtual receiver arrays, either by adding unequal spacing or by adding repetitive virtual array elements.

[0863] Figure 95This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =2, and set the number of basic sets of receiving array antennas to N. RxBaseSet Examples of MIMO array configurations with MIMO = 1 and virtual receiver array configurations. Figure 95 In this context, the horizontal offset of the second basic set (Tx#5, Tx#6, Tx#7, and Tx#8) relative to the first basic set (Tx#1, Tx#2, Tx#3, and Tx#4) is set as D. Hoffset_TxBaseSet2 =5D H Set the offset of the configuration position in the vertical direction to D. Voffset_TxBaseSet2 =0. For example... Figure 95 As shown, based on the configuration that shifts the two basic sets of the transmitting array antennas along the horizontal direction, it is possible to increase the horizontal direction by D H The number of closely spaced virtual array elements improves the angular resolution in the horizontal direction. Furthermore, in Figure 95 In this case, the virtual array elements are repeatedly configured in two locations.

[0864] Figure 96 This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =2, and set the number of basic sets of receiving array antennas to N. RxBaseSet Examples of MIMO array configurations with MIMO = 1 and virtual receiver array configurations. Figure 96 In this context, the horizontal offset of the second basic set (Tx#5, Tx#6, Tx#7, and Tx#8) relative to the first basic set (Tx#1, Tx#2, Tx#3, and Tx#4) is set as D. Hoffset_TxBaseSet2 =0, set the vertical offset of the configuration position to D. Voffset_TxBaseSet2 =3D V .like Figure 96 As shown, based on the configuration of offsetting the two basic sets of the transmitting array antenna along the vertical direction, it is possible to increase the vertical direction by D V The number of closely spaced virtual array elements improves the angular resolution in the horizontal direction. Furthermore, in Figure 96 In this case, the virtual array elements are repeatedly configured in two locations.

[0865] Figure 97 This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =1, and set the number of basic sets of receiving array antennas to N. RxBaseSet Examples of MIMO array configurations with a value of 2, and examples of virtual receiver array configurations. Figure 97In this context, the horizontal offset of the second basic set (Rx#5, Rx#6, Rx#7, Rx#8) relative to the first basic set (e.g., Rx#1, Rx#2, Rx#3, and Rx#4) is set to D. Hoffset_RxBaseSet2 =5D H Set the offset of the configuration position in the vertical direction to D. Voffset_RxBaseSet2 =0. For example... Figure 97 As shown, based on the configuration that shifts the two basic sets of the receiving array antennas along the horizontal direction, it is possible to increase the horizontal direction by D H The number of closely spaced virtual array elements improves the angular resolution in the horizontal direction. Furthermore, in Figure 97 In this case, the virtual array elements are repeatedly configured in two locations.

[0866] Figure 98 This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =1, and set the number of basic sets of receiving array antennas to N. RxBaseSet Examples of MIMO array configurations with a value of 2, and examples of virtual receiver array configurations. Figure 98 In this context, the horizontal offset of the second basic set (Rx#5, Rx#6, Rx#7, and Rx#8) relative to the first basic set (e.g., Rx#1, Rx#2, Rx#3, and Rx#4) is set to D. Hoffset_RxBaseSet2 =0, set the vertical offset of the configuration position to D. Voffset_RxBaseSet2 =3D V .like Figure 98 As shown, based on the configuration of offsetting the two basic sets of the receiving array antenna along the vertical direction, it is possible to increase the vertical direction by D V The number of closely spaced virtual array elements improves the angular resolution in the vertical direction. Furthermore, in Figure 98 In this case, the virtual array elements are repeatedly configured in two locations.

[0867] Figure 99 This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =2, and set the number of basic sets of receiving array antennas to N. RxBaseSet Examples of MIMO array configurations with a value of 2, and examples of virtual receiver array configurations. Figure 99 In this context, the horizontal offset of the second basic set (Tx#5, Tx#6, Tx#7, and Tx#8) of the transmit array antennas relative to the first basic set (e.g., Tx#1, Tx#2, Tx#3, and Tx#4) is set as D. Hoffset_TxBaseSet2 =10D HSet the offset of the configuration position in the vertical direction to D. Voffset_TxBaseSet2 =0. Additionally, in Figure 99 In this context, the horizontal offset of the second basic set (Rx#5, Rx#6, Rx#7, and Rx#8) of the receiving array antennas relative to the first basic set (e.g., Rx#1, Rx#2, Rx#3, and Rx#4) is set as D. Hoffset_RxBaseSet2 =5D H Set the offset of the configuration position in the vertical direction to D. Voffset_RxBaseSet2 =0. For example... Figure 99 As shown, based on the configuration of the two basic sets of the transmitting array antenna offset along the horizontal direction, and the configuration of the two basic sets of the receiving array antenna offset along the horizontal direction, for example, with... Figure 95 or Figure 97 In comparison, it can further increase along the horizontal direction with D H The number of closely spaced virtual array elements allows for further improvement in horizontal angular resolution. Furthermore, in Figure 99 In this case, virtual array elements are repeatedly configured in four different locations.

[0868] Figure 100A This indicates that the number of basic sets of transmitting array antennas is set to N. TxBaseSet =2, and set the number of basic sets of receiving array antennas to N. RxBaseSet Example of MIMO array configuration with 4 = 4 Figure 100B This represents a virtual receiver array configuration example.

[0869] exist Figure 100A In this context, the horizontal offset of the second basic set (Tx#5, Tx#6, Tx#7, and Tx#8) of the transmit array antennas relative to the first basic set (e.g., Tx#1, Tx#2, Tx#3, and Tx#4) is set as D. Hoffset_TxBaseSet2 =5D H Set the offset of the configuration position in the vertical direction to D. Voffset_TxBaseSet2 =00.

[0870] In addition, Figure 100A In this context, the horizontal offset of the second basic set (Rx#5, Rx#6, Rx#7, and Rx#8) of the receiving array antennas relative to the first basic set (e.g., Rx#1, Rx#2, Rx#3, and Rx#4) is set as D. Hoffset_RxBaseSet2 =5D H Set the offset of the configuration position in the vertical direction to D. Voffset_RxBaseSet2 =-3D VSet the horizontal offset of the configuration position of the third basic set (Rx#9, Rx#10, Rx#11, and Rx#12) to D. Hoffset_RxBaseSet3 =-5D H Set the offset of the configuration position in the vertical direction to D. Voffset_RxBaseSet3 =-3D V Set the horizontal offset of the configuration position of the fourth basic set (Rx#13, Rx#14, Rx#15, and Rx#16) to D. Hoffset_RxBaseSet4 =0, and set the offset of the configuration position in the vertical direction to D. Voffset_RxBaseSet4 =-6D V .

[0871] like Figure 100A and Figure 100B As shown, based on the configuration after shifting the basic set of transmitting array antennas along the horizontal direction, and the configuration after shifting the basic set of receiving array antennas along the horizontal direction, for example, with... Figure 95 or Figure 97 In comparison, it can further increase along the horizontal direction with D H The number of closely spaced virtual array elements allows for further improvement in angular resolution in the horizontal direction.

[0872] Similarly, as Figure 100A and Figure 100B As shown, based on the configuration that shifts the basic set of receiving array antennas along the vertical direction, it is possible to increase the vertical direction by D V The number of closely spaced virtual array elements improves the angular resolution in the vertical direction. Furthermore, in Figure 100B In this case, the virtual array elements are repeatedly configured in eight locations.

[0873] <Configuration Method 5-1B>

[0874] In configuration method 5-1B, it is explained that the configuration of the transmit array antenna of the four ...

Claims

1. A radar device, comprising: a radar transmit circuit which, in operation, transmits radar signals using a transmit array antenna; as well as a radar receiving circuit which receives a reflected wave signal as a radar signal reflected from a target using a receiving array antenna in operation, wherein an array antenna selected from the transmitting array antenna and the receiving array antenna includes a plurality of first antennas, The plurality of first antennas are arranged at an integer multiple of a first interval in a first direction and at an integer multiple of a second interval in a second direction orthogonal to the first direction, another array antenna selected from the transmitting array antenna and the receiving array antenna includes at least two second antenna groups, and Each of the at least two second antenna groups includes a plurality of second antennas arranged at an integral multiple of the first interval in the first direction.

2. The radar device according to claim 1, wherein: The plurality of first antennas are divided into at least two first antenna groups, and The plurality of first antennas included in each of the at least two first antenna groups are arranged in an oblique direction at an integer multiple of the first interval and an integer multiple of the second interval.

3. The radar device according to claim 2, wherein: At least one first antenna among the multiple first antennas included in one first antenna group of the at least two first antenna groups is configured at the same position in the first direction as at least one first antenna among the multiple first antennas included in another first antenna group of the at least two first antenna groups.

4. The radar device according to claim 1, wherein: Positions of the plurality of second antennas are different from each other in the first direction.

5. The radar device according to claim 1, wherein: One of the at least two second antenna groups is offset in the first direction with respect to another of the at least two second antenna groups by an interval that is one times the first interval.

6. The radar device according to claim 1, wherein: Positions of the second antenna groups are different from each other in the second direction.

7. The radar device according to claim 2, wherein: The plurality of first antennas included in each of the at least two first antenna groups are arranged at intervals twice the first interval in the first direction and at intervals once the second interval in the second direction.

8. The radar device according to claim 1, wherein: The plurality of second antennas are arranged in the first direction at intervals that are twice the first interval.

9. The radar device according to claim 2, wherein: The at least two first antenna groups are arranged at an interval in the second direction that is twice the second interval.

10. The radar device according to claim 1, wherein: The at least two second antenna groups are arranged at an interval in the second direction that is twice the second interval.

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