Radar with scanning array antenna with dielectric lens

Abstract

The invention discloses a scanning array radar device. The scanning array radar device comprises a transmitter and a receiver; wherein the transmitter comprises a first lenticular scanning array transmitter unit, the first lenticular scanning array transmitter unit comprising: a transmit antenna array, each having a respective output feed spaced apart along a first axis; a radio frequency (RF) integrated circuit (IC) configured to operate together with the transmit antenna array as a scan array transmitter; and a lens configured to focus radiation from each of the output feeds; and wherein the receiver comprises a first lenticular scanning array receiver unit, the first lenticular scanning array receiver unit comprising: a receive antenna array, each having a respective input feed spaced along a second axis; a radio frequency (RF) integrated circuit (IC) configured to operate together with the receive antenna array as a scan array receiver; and a lens configured to focus radiation reflected from a target toward each of the input feeds.

Description

Technical Field

[0001] The present disclosure relates to a radar device, such as a radar transmitter, and to a radar receiver including at least one antenna array configured for scanning array operation through a dielectric lens. Background Art

[0002] Modern radar systems, particularly for automotive applications, typically operate at radio frequencies (RF) in the millimeter wave (mmWave) range between 30 GHz and 300 GHz. Many automotive radar systems currently under development or recently implemented operate in the 77 GHz range (approximately 76 GHz to 81 GHz) and the 140 GHz range (between 134 GHz and 141 GHz and between 141 GHz and 148.5 GHz).

[0003] Some radar systems, particularly but not limited to imaging radars, may require high angular resolution, particularly in azimuth (left and right for typical automotive applications). Although the resolution requirements for elevation (up and down or altitude for typical automotive applications) are generally less stringent, frequent detections based on elevation are also required. Known solutions to this problem include multiple-input, multiple-output (MIMO) arrays using microstrip-based or waveguide-based antennas. However, the limitations of these technologies, including limited equivalent isotropic radiated power (EIRP), limited resolution, large distribution losses, and limited sensor size, tend to be more pronounced at high frequencies, and thus, for example, the recent trend from 77 GHz to 140 GHz operating frequencies for many automotive radars has exacerbated these problems.

[0004] For applications such as automotive radar, the traditional method of physically rotating the radar transmitter or receiver has been replaced by electronically scanning the device over a range of directional angles, which may also be referred to as the "field of view" (FOV). This electronic scanning is typically performed using scanning array technology. In a scanning array radar transmitter, multiple antennas are linearly spaced apart and used to produce copies of the transmitted signal. The signal may be a single frequency tone, continuous or intermittent, or more commonly a tone with a gradually varying, usually triangular or sawtooth frequency ("chirp"). The relative phase (and possibly amplitude) of each copy of the transmitted signal varies across the antenna, which results in constructive interference between the copies only at certain angles, thereby producing a directionally focused signal. As will be discussed in more detail below, for a particular phase difference, there is typically more than one unique angle at which the signal is maximum (with a minimum in between); the angle or angles depend on the wavelength of the radiation, the phase difference, the spacing between each antenna, and the transmission medium. By varying the phase difference, the relative phase (and possibly amplitude) of each copy of the transmitted signal can be varied at the F OThe direction of the transmitted signal is scanned across V. As a corollary, the angle of arrival at a scanning array radar receiver can be determined by calculating the phase offset between the antennas at which the replicas of the incoming signal from the antennas sum to the maximum measurable signal.

[0005] Maximizing radar effectiveness includes maximizing object detection. Since this relies on correctly identifying reflections as potential targets, maximizing and smoothing the output power or gain of both the antenna and the receiver (or transmitter) containing the antenna remains a topic of concern. Summary of the Invention

[0006] According to a first aspect of the present disclosure, a scanning array radar apparatus is provided, comprising a transmitter and a receiver; wherein the transmitter comprises a first lensed scanning array transmitter unit, the first lensed scanning array transmitter unit comprising: an array of transmit antennas, each having a corresponding output feed, the output feeds having phase centers spaced apart along a first axis; a radio frequency integrated circuit (RF) configured to operate with the transmit antenna array as a scanning array transmitter; and a lens configured to focus radiation from each of the output feeds; and wherein the receiver comprises a first lensed scanning array receiver unit, the first lensed scanning array receiver unit comprising: an array of receive antennas, each having a corresponding input feed, the input feeds having phase centers spaced apart along a second axis; an RF IC configured to operate with the receive antenna array as a scanning array receiver; and a lens configured to focus radiation reflected from a target toward each of the input feeds. The scanning array transmitter comprises the RF IC of the lensed scanning array transmitter unit and can be considered to comprise a transmit antenna with an output feed. A scanning array receiver comprises the RF IC of the latest phased array receiver unit and can be considered to comprise a receiving antenna with an input feed. The use of a lens to focus the radiation from (or to) each antenna into a directional beam provides an alternative to traditional phased array technology. By combining scanning array technology including the use of multiple antennas under a lens, such scanning array radar devices can have relatively high input and / or output gain and can be adapted with respect to beam directivity or angular discrimination. Therefore, it can be suitable for a range of applications, including but not limited to automotive radar applications, in particular short-range radars, medium-range radars and long-range radars for such automotive applications. The combination of multiple antennas under a single lens will hereinafter be referred to as a "lens scanning array transmitter (or receiver) unit", where the multiple antennas are used to provide directional scanning - typically by weighting at least the amplitude associated with the antennas.

[0007] In one or more embodiments, the first lens-scanned array transmitter element RF IC and the first lens-scanned array transmitter element antenna array are integrated within the transmitter package, and the first lens-scanned array receiver element RF IC and the first lens-scanned array receiver element antenna array are integrated within the receiver package. Providing such a packaged antenna solution can allow for low manufacturing costs and high geometric tolerances between components.

[0008] In one or more embodiments, the lens is one of an elliptical shape and a hyper-hemispherical shape.Such a solution may provide a wide range of configurability for the radar device or one or both of the transmitter and receiver.

[0009] In one or more embodiments, the scanning array radar apparatus further includes a frequency synthesizer configured to provide a common local oscillator (LO) signal to the first lens-scanned array transmitter unit RF IC and the first lens-scanned array receiver unit RF IC. Providing a common LO signal to each of the transmitter unit and the receiver unit can facilitate ensuring coherence or coherent reception of signals from individual antennas.

[0010] In one or more sets of embodiments, the transmitter may function as a first transceiver, and the first lens-scanning array transmitter unit is a first lens-scanning array transceiver unit, the first lens-scanning array transceiver unit further comprising: a second receive antenna array, each having a corresponding input having a phase center spaced apart along a third axis, the third axis being parallel to and spaced apart from the first axis; and a second radio frequency (RF) integrated circuit (IC) configured to operate with the second receive antenna array as a scanned array receiver; and the receiver may function as a second transceiver, and the first lens-scanning array receiver unit is a second lens-scanning array transceiver unit, the second lens-scanning array transceiver unit further comprising: a second transmit antenna array, each having a corresponding output feed having a phase center spaced apart along a fourth axis, the fourth axis being parallel to and spaced apart from the second axis; and a second radio frequency (RF) integrated circuit (IC) configured to operate with the second transmit antenna array as a scanned array transmitter. Thus, the scanned array radar device may be manufactured as a pair of similar units, each unit acting as both a transmitter and a receiver. Since the transceivers can be identical, this may be commercially helpful in reducing the number of different components required.

[0011] In one or more embodiments, the frequency synthesizer is further configured to provide the common local oscillator signal to the first lens scanning array transceiver unit, the second lens scanning array transmitter unit RF IC, and the second lens scanning array transceiver unit, the second lens scanning array receiver unit RF IC, thereby ensuring coherence between the transceivers.

[0012] In one or more second group of embodiments, the first axis is parallel to the second axis.According to such embodiments, the or any received signal may have the same polarization as the or any polarization of the transmitted signal.

[0013] In one or more embodiments, the second receive antenna array of the first lens-scanned array transceiver unit is configured to receive reflected radiation having a polarization orthogonal to the polarization of radiation emitted by the first transmit antenna array of the first lens-scanned array transceiver unit; and the first receive antenna array of the second lens-scanned array transceiver unit is configured to receive reflected radiation having a polarization orthogonal to the polarization of radiation emitted by the second transmit antenna array of the second lens-scanned array transceiver unit. By using orthogonal polarizations between the transmitters of the two receivers, effective discrimination between the two signals can be achieved.

[0014] In one or more embodiments, the second receiving antenna array of the first lens-scanned array transceiver unit is configured to receive radiation reflected by a target from radiation emitted by the second transmitting antenna array of the second lens-scanned array transceiver unit; and the first receiving antenna array of the second lens-scanned array transceiver unit is configured to receive radiation reflected by the target from radiation emitted by the first transmitting antenna array of the first lens-scanned array transceiver unit.

[0015] In one or more embodiments, the scanning array transmitter of the first lens-type scanning array transmitter unit is configured to scan over an angular range of at least 80°. Scanning over a large angular range, such as at least 80°, may be particularly useful for short-range radar applications. Such an angular range of at least 80° may generally be symmetrical about an axis, i.e., at least + / - 40°.

[0016] In one or more embodiments, the scanning array radar device is configured for use as an automotive radar having an azimuth half-power beamwidth of less than 3° and an elevation half-power beamwidth of less than 20°. Providing an azimuth resolution of less than 3° can allow for good azimuth discrimination or angular resolution, which can be useful for applications such as automotive applications. Generally speaking, lower elevation resolution (e.g., 10° or greater) can be acceptable for applications such as automotive applications.

[0017] In one or more third group of embodiments, the scanning array radar apparatus further comprises a first plurality of transceivers aligned with the first transceiver along the first axis, and a second plurality of transceivers aligned with the second transceiver along the second axis. Providing a plurality of transceivers aligned along each of the first and second axes may allow for a larger effective aperture of the scanning array transmitter. This, in turn, may allow for more accurate angular resolution, particularly in azimuth.

[0018] In one or more such embodiments, the first transceiver and each of the first plurality of transceivers are adjacent to the first transceiver and adjacent transceivers in the first plurality of transceivers; and the second transceiver and each of the second plurality of transceivers are adjacent to the second transceiver and adjacent transceivers in the second plurality of transceivers, and adjacent to the first transceiver and transceivers in the first plurality of transceivers. The adjacent adjacent transceivers can help minimize the coverage area of ​​the scanning array radar device. In some applications, such as automotive applications for small cars, it may be desirable to minimize the coverage area or overall size of the scanning array radar device.

[0019] In one or more embodiments, the scanning array radar device is configured to operate in one of a RF frequency range between 76 GHz and 81 GHz and a RF frequency range between 134 GHz and 141 GHz. Although the present disclosure is not limited to these frequency ranges, in many jurisdictions these ranges are allocated for radar applications such as automotive radar.

[0020] In one or more embodiments of the fourth group of embodiments, the first axis is orthogonal to the second axis. In one or more such embodiments, the scanning array radar apparatus further includes a first plurality of transmitters aligned with the first transmitter along the first axis, and a plurality of receivers aligned with the receiver along the second axis. By aligning the plurality of transmitters along a first axis orthogonal to the second axis along which the plurality of receivers are aligned, the effective aperture of the scanning array radar is increased for both the transmitters and the receivers. This may allow for more precise angular resolution in both azimuth and elevation.

[0021] In one or more such embodiments, the lens of the transmitter and the lens of each of the plurality of transmitters each have a first focal length in the direction of the first axis and a second focal length in the direction of the second axis that is different from the first focal length. Providing a different focal length in the first (x) direction as compared to the focal length in the orthogonal second (y) direction can provide different focus positions for transmitted and / or received signals.

[0022] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Embodiments will be described, by way of example only, with reference to the accompanying drawings, in which:

[0024] Figure 1 A schematic diagram showing a lens-type scanning array transmitter (or receiver) unit;

[0025] Figure 2 shows a radiation pattern from coherent excitation of multiple antenna elements of a multi-antenna lens-scanned array transmitter unit, steered into each of several different directions;

[0026] Figure 3 showing a plurality of scanning array transmitter elements aligned along the same axis as the antenna within each element;

[0027] Figure 4 shows the radiation pattern from an array of lens-scanned array transmitter (or receiver) units;

[0028] Figure 5 schematically illustrates an analog beamforming transmitter array consistent with one or more embodiments of the present disclosure;

[0029] Figure 6 A lens-scanned array transmitter unit is shown, along with a plurality of three further such units, each driven by the same LO signal from a frequency synthesizer;

[0030] Figure 7 Schematically illustrates a digital beamforming architecture for a receive array consistent with one or more embodiments of the present disclosure;

[0031] Figure 8 A lens array receiving unit is shown, along with a plurality of three further such units, each processed by an ADC and a MIMO processing unit;

[0032] Figure 9 shows the (incoherent) reception pattern from the set of antennas located in the same relative position at each cell;

[0033] Figure 10 A scanning array radar apparatus including a transmitter and a receiver according to a first set of embodiments of the present disclosure is shown;

[0034] Figure 11 Shown at various azimuth scan angles Figure 10 Bidirectional radiation pattern (i.e., from the transmitting unit and through the receiving unit);

[0035] Figure 12 A scanning array radar apparatus including a transmitter and a receiver according to a second set of embodiments of the present disclosure is shown;

[0036] Figure 13 Shown at various azimuth scan angles Figure 12 Bidirectional radiation pattern (i.e., from the transmitting unit and through the receiving unit);

[0037] Figure 14 Shown at two elevation angles Figure 12 Bidirectional radiation pattern (i.e., from the transmitting unit and through the receiving unit);

[0038] Figure 15 A scanning array radar device including a transmitter and a receiver according to a third set of embodiments of the present disclosure is shown;

[0039] Figure 16 Shown at various azimuth scan angles Figure 15 Bidirectional radiation pattern (i.e., from the transmitting unit and through the receiving unit);

[0040] Figure 17 Shown at two elevation angles Figure 15 Bidirectional radiation pattern (i.e., from the transmitting unit and through the receiving unit);

[0041] Figure 18 A scanning array radar device including a transmitter and a receiver according to a fourth set of embodiments of the present disclosure is shown;

[0042] Figure 19 Shown at a scan angle of approximately 4 degrees from normal Figure 18 Bidirectional radiation pattern (i.e., from the transmitting unit and through the receiving unit); and

[0043] Figure 20 Shown at a scan angle of approximately 4 degrees from normal Figure 18 Bidirectional radiation pattern (i.e., from the transmitting unit and through the receiving unit).

[0044] It should be noted that the drawings are diagrammatic and not drawn to scale. For clarity and convenience in the drawings, the relative sizes and proportions of the various parts of these drawings have been shown by enlarging or reducing them in size. The same reference numerals are generally used to designate corresponding or similar features in modified and different embodiments. DETAILED DESCRIPTION

[0045] One way to increase the directivity and gain of the directional peak of a transmitted radar signal (or equivalently, to increase the directional discrimination of a received radar signal) is to focus the transmitted signal using an optical lens. At millimeter-wave frequencies of electromagnetic (EM) radiation, it is more accurate to refer to a "dielectric lens" rather than an "optical lens." Dielectric lenses operate based on refraction at the lens-air interface and the speed of radiation through the material, which is determined by its refractive index. Dielectric lenses at millimeter-wave frequencies are typically made of plastic materials. A lens has an "F-number" defined as the ratio of its focal length to its diameter. A single lens can be located above the feed antenna array.

[0046] Figure 1 A schematic diagram of a lens-scanned array transmitter (or receiver) unit is shown. Unit 100 includes a semiconductor device or integrated circuit (IC) 110 as an RF front end ("RFE"). As shown, RFE 110 can be integrated into a package 120. In the case of a transmitter, RFE 110 generates multiple copies of the radar signal on a signal path such as a stripline or feed line 130. As shown, package 120 can include a so-called "antenna in package" (AiP) or packaged transmitter, in which the antenna feed is integrated within the package. As schematically shown, the antenna feed can be a slot antenna 140. The antenna is planar and can be a slot, a dipole, a patch, or a combination thereof. Antenna 140 is typically arranged in a linear array at a first major surface of package 120. Lens 150 is disposed above antenna 140.

[0047] If unit 100 is a transmitter unit, the lens serves to focus radiation from antenna 140 in a specific direction O. RFE 110, together with antenna 140, is configured to operate as a scanning array radar transmitter, in which copies of the radar signal transmitted by two or more of the antennas are adjusted in phase and amplitude. Conversely, if unit 100 is a receiver unit, the lens serves to focus incoming radiation from a specific direction toward antenna 140. Any antenna receiving a copy of the same signal receives a copy with a different phase and amplitude. Due to the focusing effect of the lens, typically only two or three receivers receive the signal. RF front-end IC 110 partially processes the incoming signal for later processing in a processor to reconstruct the signal from the specific angle O and the reflection from the radar system's target object from that specific angle O.

[0048] To achieve the desired field of view, the lens (or each lens in the case of multiple lenses as will be discussed further below) is composed of a lens having N a The antenna is fed by a planar antenna array of elements that steer the high gain element pattern in the desired direction. Figure 1 In FIG, four such antennas or antenna elements are shown. The spacing d between these antennas is typically arranged as d ≈ λ. d .f# , where λ d is the wavelength in the lens material, and f # is the equivalent focal length to diameter ratio of the lens. The spacing is chosen to maximize the gain of the individual elements while enabling continuous scanning of the element pattern. The field of view (FoV) is then determined based on the number of antennas under each lens:

[0049] FoV~Na.λ0 / Dlens

[0050] Where λ0 is the wavelength in free space. And Dlens is the diameter of the lens. This pattern steering can be performed using a digital or analog beam scanning architecture, where the amplitude and phase of the planar antenna vary depending on the desired steering direction. The amplitude and phase of each antenna i are referred to as the antenna weight wi. To achieve scanning of the complete array pattern, the amplitude and phase are modified between different array elements. Due to the focusing action of the lens, the amplitude of some or even most of the array elements will be zero.

[0051] Figure 2 The radiation pattern from the coherent excitation of multiple antennas or antenna elements of such a multi-antenna lens-scanned array transmitter unit is shown, which are steered (at 212, 214, 216, etc.) to each of several different directions or values ​​of O (an overlap of 11 directions is shown). As can be seen from the figure, the antenna steering produces a main beam at a given angle O, as well as side lobes. (In this example, the first side lobe is separated from the main lobe by about 10° and is about 18 dBi weaker, and the second side lobe is offset by about 7° and reduced in strength by another 8 dBi).

[0052] To improve directivity, the size of the antenna array can be increased. This can be conveniently achieved by using multiple lens-scanned array transmitter units 100, such as Figure 3 As shown in . Figure 3 A plurality of scanning array transmitter elements 100 are shown aligned along the same axis with antennas 140 within each element. Figure 3 An exemplary multi-lens transmitter 300 is shown in which there are four such scanning array transmitter units 100 .

[0053] Figure 4 The radiation pattern of such a multi-lens transmitter 300 is shown in FIG (i.e., signal strength dBi plotted against angle O). This plot has two components that interact to produce the final radiation pattern from the multi-lens transmitter 300. First, the radiation pattern of a single antenna element 140 is shown at 410 (as previously described with respect to FIG). Figure 2The array factor (as mentioned above) has a main beam and sidelobes, with the first sidelobe offset from the main beam by approximately 10° and approximately 18 dBi weaker. The second component is the array factor 420. This is caused by interference between two individual antenna elements within a single lens element 100 and multiple lens elements. Because the total number of elements is not evenly spaced, but grouped within individual lenses, this array factor exhibits a raster pattern with main peaks 422 spaced approximately 7° apart, and sub-peaks 424 spaced approximately 2° apart between the main peaks 422. The multiplication of these two components yields the overall radiation pattern from the multi-lens transmitter 300.

[0054] Therefore, the coherent transmit signal Tx (or receive signal Rx) from the cascade radar can be transmitted (and received) by the lens antenna array to achieve high gain per element, reduce grating lobes and enhance radar angular resolution. Figure 3 An array of Ni lenses with a diameter greater than the wavelength (such that Dlens>λ0) corresponding to the array period is shown. Due to the large electrical periodicity, the array factor associated with such an array has multiple grating lobes, such as Figure 4 When the lenses in the array are illuminated with sufficient feed at high aperture efficiency, the element pattern has sufficient directivity (410) to reduce the level of grating lobes in the array pattern, as shown in Figure 4 Thus, the lens array can improve the angular resolution by a factor of Ni relative to a single lens of diameter Dlens while achieving a low level of grating lobes.

[0055] In order to achieve the required beamforming weights wi for each lens-scanned array transmitter unit 100, according to an embodiment of the present disclosure, for each Tx RFE IC 500, a transmit array operating in an analog beamforming architecture may be used, such as Figure 5 The Tx RFE IC may be referred to as a follower IC because it may be supplied from a separate leader IC, and typically each follower IC will have the same local oscillator (LO) signal supplied from the same frequency generator or synthesizer 510. The Tx RFE IC will include an N-type signal consisting of the following: a Chain: frequency multiplier (×N) 520 to upconvert the signal from LO to radar frequency; magnitude controller 530 to set the relative amplitude of each antenna feed; phase controller 540 configured to set the relative phase of each antenna feed; and power amplifier 550 to increase the power of each antenna feed (by the same amount). This configuration enables the power from the transmitters to be combined in the air via the lens array. In this case, the total output power is transmitted from up to 4 RF ICs. If we consider using the maximum power available from 2 Tx but distributed over 4 Tx, the maximum power is equivalent to 2×P max, where P max = is the maximum output power per Tx channel, so all four channels can be active simultaneously without compromising thermal IC performance. The power is focused into a single directional beam, increasing the total equivalent isotropic radiated power (EIRP) of the radar system.

[0056] Figure 6 The lens-type scanning array transmitter unit 100 is shown along with a plurality of three further lens-type scanning array transmitter units 100, each of which is driven by the same LO signal from a frequency generator or synthesizer 510 to provide a frequency such as Figure 3 The steerable multi-lens emitter 300 is shown in FIG.

[0057] Figure 7 Schematically illustrates a digital beamforming architecture 700 for a receive array consistent with one or more embodiments of the present disclosure, and Figure 8 A lensed scan array receiver unit 100 is shown, along with a plurality of three further such units 100, each driven by the same LO signal from a frequency generator or synthesizer 510, to provide a steerable multi-lens receiver. It will be appreciated that Figure 8 The block-level receiver process chain shown in is the counterpart of the transmitter chain.

[0058] The Rx RFE follower chip 710 will include an N-type low noise amplifier (LNA) 720 and a down converter 730 per element. a chain. At the director end, there will be a signal processing unit. This unit can perform initial processing on the range and speed of each of the signals received by the array under each of the lenses 150. This is associated with the incoherent Rx pattern corresponding to one antenna under the lens, such as Figure 8 The signals received by the planar antennas (e.g., 742, 744, 746) located in different cells but at the same position relative to the cells are substantially identical except for the phase delay element. Figure 9 The (incoherent) receive patterns from the antenna group located in the same relative position at each unit are shown. Thus, the receive pattern from antennas 742, 744, 746 is shown in the pattern at 942 (with side lobe 942'); similarly, the receive pattern from antennas 743, 745, 747 is shown in the pattern at 943 (with side lobe 943').

[0059] The signal-to-noise ratio (SNR) at this point will be based on the gain of the individual antennas, which roughly corresponds to the gain of a single lens minus 1-3 dBi. The unit will now be able to detect targets with an angular resolution roughly that of a single lens, Δθ ~ λ0 / Dlens. As a second processing step after analog-to-digital conversion (ADC) 750, all of these signals are combined using digital beamforming in the MIMO processing unit 760 (i.e., the combined signal is combined with a weight w associated with a particular scan direction). i Those skilled in the art will appreciate that the ADC processor 750 performs conventional radar signal analysis, including peak detection and range and velocity processing. The angular resolution and resulting SNR will increase Ni. This allows for continuous coverage across the entire FoV.

[0060] With an understanding of the processing required for one or more lens-scanned array transmitters and receivers, several radar physical layout architectures will now be described that can meet the various requirements of radars, particularly but not exclusively automotive radars, in accordance with embodiments of the present disclosure.

[0061] like Figure 10 As shown in FIG, according to a first set of embodiments of the present disclosure, there is a scanning array radar device 1000 comprising a transmitter 1010 and a receiver 1060. The transmitter comprises a single lens-scanning array transmitter unit, and the receiver comprises a single lens-scanning array receiver unit. The size of the lens 1020 of the lens-scanning array transmitter unit and the lens 1070 of the lens-scanning array receiver unit can each be selected to suit the application, but for typical automotive short-range radar applications requiring wide azimuth scanning, the lens size can be set to have a diameter Dlens, which can be, for example, in the range of between 4.λ0 and 10.λ0, where λ0 is the wavelength of the radar signal. The spacing can be approximately equal to the wavelength λd in the lens medium.

[0062] The lensed scanning array transmitter unit includes an array of transmit antennas, each having a corresponding output feed (or feed phase center) 1032, 1034, 1036, etc. spaced along a first axis 1040. A lens 1020 is configured to focus radiation from each of the output feeds. The lensed scanning array receiver unit includes an array of receive antennas, each having a corresponding input feed 1082, 1084, 1086, etc. spaced along a second axis 1090. A lens 1070 is configured to focus radiation reflected from a target toward each of the input feeds. The second axis may be parallel to the first axis 1040. The lensed scanning array transmitter unit includes a radio frequency (RF) integrated circuit (IC) configured to operate with the transmit antenna array as a scanned array transmitter. The RF IC may be an RFE director 1045. The RFE director 1045 may be integrated with the transmit antenna array output feeds in a package 1048, thereby providing an antenna-in-package (AiP) configuration. The lensed scanned array receiver unit includes an RFIC configured to operate as a scanned array transmitter in conjunction with a transmit antenna array. The RFIC may be an RFE follower 1095. The RFE follower 1095 may be integrated in a package with the receive antenna array as an AiP configuration. The package for the receiver may be separate from the package for the transmitter, or they may be the same package, such as Figure 10 As shown, at an operating frequency of 140 GHz, a lens diameter Dlens of 5.λ0 corresponds to approximately 10.7 mm. Therefore, the scanning array radar device can have dimensions of approximately 24.7 mm x 10.7 mm (leaving a gap of just over 3 mm between the lenses).

[0063] According to such Figure 10 In the embodiment shown in , each of the transmit and receive lenses may be partially spherical or partially elliptical, shown with a circular footprint. In other embodiments, considered in more detail below, the lenses may not have such a high degree of symmetry.

[0064] Figure 11 Bidirectional radiation patterns 1110, 1112, 1114, etc. are shown at various azimuth scan angles O (11 separate scan angles are shown). Those skilled in the art will recognize that this figure shows the product of the radiation pattern transmitted from the transmitter unit and the radiation pattern received back by the receiver unit - the radiation pattern can therefore be described as "bidirectional", and if (for any particular direction) the transmit gain is the same as the receive gain, then this dual pattern shows the square of the individual gain patterns. As can be seen, the beam has a width of approximately 20° (a 15dBi reduction from its peak gain). For example Figure 10 The performance indicators of the device shown in FIG may include a gain of approximately 22.5 dBi. 8.4° / 8.4° azimuth discrimination (i.e. antenna half-power beamwidth) 100° accessible field of view (FOV A ), radar range of 73.7m 10dBsm target cross section The device has a speed discrimination Δv of 2.3 km / h and a device coverage area of ​​approximately 1 cm × 2.4 cm.

[0065] Steering Figure 12 According to a second set of embodiments of the present disclosure, there is a scanning array radar device 1200 comprising a transmitter and a receiver. In such embodiments, the transmitter functionality may be distributed across two lens-scanning array elements 1210 and 1260, and the receiver functionality may be distributed across the same two lens-scanning array elements 1210 and 1260. Thus, each of the elements may function as a lens-scanning array transceiver element. Transceiver elements 1210 and 1260 may be functionally and topologically identical.

[0066] That is, in such embodiments, the first lens-scanning array transmitter unit is the first lens-scanning array transceiver unit 1210. In addition to having a transmit antenna array, each having a corresponding output feed 1222, 1224, 1226, etc., spaced apart along a first x-axis 1228, the first lens-scanning array transceiver unit 1210 also includes a second receive antenna array, each having a corresponding input feed 1232, 1234, 1236, etc., spaced apart along a third axis 1238, the third axis 1238 being parallel to and spaced apart from the first axis. The third axis 1238 may be displaced from the first axis 1228 by a distance corresponding to approximately 1.5*λ. d *f # The distance, where λ d is the wavelength of the emitted (or received) radiation in the lens medium, and f # is the number of focal points of the lens. For a typical 140 GHz radar system having a lens material made of, for example, a high-density polyethylene (HDPE) or polytetrafluoroethylene (PTFE) plastic material, the spacing may be approximately 1.4 mm. The first lens-mounted scanning array transceiver unit 1210 includes a first RFE configured to operate as a scanning array transmitter in conjunction with a transmit antenna array and a second RFE configured to operate as a scanning array receiver in conjunction with a second receive antenna array. The scanning array transmitter and scanning array receiver RFEs may be separate ICs, each of which may be integrated with a corresponding antenna to provide a corresponding packaged antenna arrangement, or, as shown, they may be integrated into a single RFE 1230 that is integrated with both the transmit antenna and the receive antenna in a single packaged antenna arrangement 1240.

[0067] Similarly, the first lensed scanning array receiver unit is a first lensed scanning array transceiver unit 1260. In addition to having a receive antenna array, each having a corresponding input feed 1272, 1274, 1276, etc., spaced apart along a second x' axis 1278, the first lensed scanning array transceiver unit 1210 also includes a second transmit antenna array, each having a corresponding output feed 1282, 1284, 1286, etc., spaced apart along a fourth axis 1288, parallel to and spaced apart from the second axis. The second lensed scanning array transceiver unit 1260 includes a first RFE configured to operate as a scanned array receiver with the receive antenna array and a second RFE configured to operate as a scanned array transmitter with the second transmit antenna array. The scanning array transmitter and scanning array receiver RFE can be separate ICs, each of which can be integrated with a corresponding antenna to provide a corresponding packaged antenna device, or as shown, they can be integrated into a single RFE 1280, which is integrated with both the transmitting antenna and the receiving antenna in a single packaged antenna device 1290.

[0068] Each of the first scanning array transceiver unit 1210 and the second lens-type scanning array transceiver unit 1260, in particular RFE 1230 and 1280, can be fed from a common frequency synthesizer or local oscillator 1295 to provide a common operating frequency. The frequency synthesizer can provide a suitable subharmonic of the radar's operating frequency f (such as f / 4, f / 6, or f / 8).

[0069] In operation, each of the lenses of lens-type units 1210, 1260 is fed by an x-plane linear array of planar antennas located on the x-axis at y = 0. The signal Tx1 transmitted from the Tx linear array in lens-type unit 1210 is received by the Rx linear array in lens-type unit 1260. Using these linear arrays, continuous scanning of the azimuth angle is achieved. Figure 13 The bidirectional patterns achieved for a range of scan angles 1310, 1320, etc. are shown. Figure 14 The radiation pattern shows a separate peak at elevation for each of the Tx / Rx pairs, and since the two lenses are separated vertically on the graph (i.e., on the Y axis), approximately 9° of elevation discrimination can be achieved between the two curves 1410 and 1420. Each of the lens elements also has a peak at elevation between y and 1.5λ. d f # The second x-plane linear array of planar antennas at , but with orthogonal polarization to reduce coupling with the y=0 array. In addition, these linear arrays of orthogonally polarized Tx and Rx antennas are swapped with respect to the previous lens, as described above and in Figure 12 Thus, each lens can be used as Figure 5 and Figure 7 For a specific frequency modulated continuous wave (FMCW), the performance indicators may include a gain of approximately 28.2 dBi for a chirped scheme with a 2-lens lens array topology with Dlens = 10λ0 and Na = 4. 4.2° / 4.2° azimuth discrimination (i.e. antenna half-power beamwidth) 18° / 9° accessible field of view (FOV A ), radar range of 160m 10dBsm target cross section The speed discrimination Δv is 0.77 km / h, and the device coverage area is approximately 4.2 cm × 2.1 cm. Based on the above performance indicators, it is obvious to those skilled in the art that this topology can be well suited for applications such as medium-range radar (MRR) for automotive applications. The topology can be referred to as Tx / Rx lenses with polarization multiplexing to achieve azimuth scanning and elevation detection.

[0070] Steering Figure 15 According to a third set of embodiments of the present disclosure, there is a scanning array radar device 1500 comprising a transmitter and a receiver. Figure 12 In the described embodiment, the transmitter functionality is spread across multiple transceivers, as is the receiver functionality. Again similar to the above description of Figure 12 In the embodiment shown, the scanning array radar apparatus comprises a first scanning array transceiver unit 1210 and a second scanning array transceiver unit 1260, the two units being offset from each other in the y direction. The transceiver units may be similar to Figure 1 2 and may be fed with a signal from a single frequency synthesizer or local oscillator 1295, which may be a sub-harmonic of the radar operating frequency. Figure 15 In the embodiment shown in FIG, there are multiple additional pairs of transceiver units, which are shown as three additional pairs of transceiver units: 1512 and 1562, 1514 and 1564, and 1516 and 1566. The pairs are offset in the x-direction. Each pair is fed a signal from frequency synthesizer / local oscillator 1295. This configuration may be suitable for long-range radar applications in automotive applications, among other applications.

[0071] Will Figure 15 The embodiments shown in Figure 12Compared to the embodiment shown in [1], the topology is scaled to a lens array for long-range applications to enhance angular resolution. In this configuration, two lens arrays with N1 lens elements are implemented. Using these linear lens arrays, continuous scanning of the azimuth angle with narrow angular resolution is achieved. Figure 16 The bidirectional pattern achieved in azimuth is shown for a range of scan angles O. The use of multiple transceiver units results in a signal scan where several (in this case four) antenna feeds are grouped closely together under each lens with large spacing between each group, and individual angles have main peaks such as shown at 1610 and 1620 and side lobes such as shown at 1612 and 1622. Figure 17 Shows the bidirectional radiation pattern at elevation angles. Similar to Figure 14 , which shows the discrimination resulting from each pair of transceiver units separated in the y direction. Since multiple additional pairs are aligned with the first pair and separated by the same distance in the y direction, the discrimination of elevation angles (responses 1710 and 1720 separated) is the same as described above with respect to Figure 14 The expected performance for a particular FMCW chirp scheme for a lens array topology with N1 pairs of lenses (each with Dlens = 10λ0 and Na = 4) includes a gain of approximately 34.5 dBi. 1.0° / 4.2° azimuth discrimination (i.e. antenna half-power beamwidth) 18° / 9° accessible field of view (FOV A ), radar range of 10dBsm target cross section of 315m The speed discrimination Δv is 3.5 km / h, and the device coverage area is approximately 8.5 cm × 4.2 cm. Based on the above performance indicators, it is obvious to those skilled in the art that this type of topology, which can be referred to as a Tx / Rx lens array with polarization multiplexing for elevation detection and designed to achieve narrow resolution in azimuth scanning, can be very suitable for applications such as long-range radar (LRR) for automotive applications.

[0072] Steering Figure 18According to a third set of embodiments of the present disclosure, there is a scanning array radar device 1800 comprising a transmitter 1810 and a receiver 1860. Transmitter 1810 comprises a plurality (four in the illustrated example) of lensed scanning array transmitter units 1820. Each lensed scanning array transmitter unit 1820 comprises an array of transmit antennas, each having a respective output feed 1822, 1824, 1826, etc. spaced apart along a first axis. Each lensed scanning array transmitter unit further comprises an RF IC or RFE 1830 configured to operate as a scanning array transmitter in conjunction with the transmit antenna array, and a lens 1840 configured to focus radiation from each of the output feeds. In the illustrated example, lenses 1840 are asymmetric; rather, lenses 1840 are configured to have a different focal length in the y-direction than in the x-direction. However, in plan view, as shown, the lens is not circular, but rather elliptical. Additionally, the lens may have an electrical profile in the z-direction (that is, outside the plane of the drawing). Those skilled in the art will appreciate that the lens may have different configurations, as long as the lens achieves the same functionality with a focal length in the y-direction that is different from the focal length in the x-direction.

[0073] The scanning array transmitter elements 1820 are offset along a first axis in the y-direction 1805 as shown. Within each transmitter element 1820, an array of antenna output feeds 1822, 1824, 1826, etc. are spaced apart along the same axis 1805.

[0074] Receiver 1860 of scanning array radar apparatus 1800 includes a plurality (four in the illustrated example) of lensed scanning array receiver elements 1870. Each lensed scanning array receiver element 1870 includes an array of receive antennas, each having a corresponding input feed 1872, 1874, 1876, etc., spaced apart along a second axis. The second axis is orthogonal to the first axis. Each lensed scanning array receiver element further includes an RF IC or RFE 1880 configured to operate as a scanning array receiver with the array of receive antennas, and a lens 1890 configured to focus radiation onto each of the input feeds. In the illustrated example, lenses 1890 are symmetrical, i.e., they are circular in plan view. Additionally, the lenses may have an electrical profile in the z-direction (i.e., outside the plane of the drawing).

[0075] The RFEs 1830 and 1880 in each of the scanning array transmitter unit 1820 and the scanning array receiver unit 1870 are fed with the same local oscillator signal from a common frequency synthesizer 1895. As described above, the frequency synthesizer may be configured to provide a signal that is a subharmonic of the radar's operating frequency.

[0076] Therefore, according to this topology, two linear lens arrays of N1 elements are placed orthogonally to each other to achieve narrow angular resolution and continuous scanning in azimuth and elevation. Each of the lens arrays is fed by a linear array of planar antennas in the same direction. One array has Tx antennas with elevation scanning and the other array has Rx antennas with azimuth scanning. The shape of the Tx lens in the azimuth direction is optimized to maximize the azimuth FoV. Figure 18 In the example shown in , the Tx lens is elliptical to reduce the directivity of the Tx array in the azimuth plane. The Rx array has greater directivity in elevation, which results in a narrower FoV in elevation. Figure 19 The bidirectional radiation pattern achieved at a scan angle of approximately 4 degrees from the normal is shown. The transmitter azimuth radiation pattern is shown at 1910, the receiver radiation pattern is shown at 1920, and the combination of the gains corresponding to the reflected signals is shown at 1930. In each case, the radiation patterns are normalized to their maximum values. Similarly, Figure 20 The corresponding realized elevation radiation pattern at the edge of the FoV is shown. The receiver radiation pattern is shown at 2010, the transmitter radiation pattern is shown at 2020, and the combination of gains corresponding to the reflected signals is shown at 2030. In this topology, each lens is integrated with a separate Tx / Rx RFE follower unit. The expected performance for a particular FMCW chirp scheme for such a topology with N1=4, Dlens(x)=10λ0, Dlens(y)=3λ0, and Na=4 includes a transmit gain of approximately 29.4 dBi. Roughly 34.5dBi receiving gain 1.4° / 1.4° azimuth discrimination (i.e. antenna half-power beamwidth) 18° / 8° azimuth / elevation accessible field of view (FOVA / E ), radar range of 308's 10dBsm target cross section The device has a speed discrimination Δv of 1.16 km / h and a device coverage area of ​​approximately 10.7 cm × 8.5 cm.

[0077] From reading this disclosure, other variations and modifications will be apparent to those skilled in the art.Such variations and modifications may involve equivalent and other features which are already known in the art of scanning array radar apparatuses and which may be used instead of or in addition to features already described herein.

[0078] Although the appended claims are directed to particular combinations of features, it should be understood that the scope of the disclosure of the present invention also includes any novel feature or any combination of novel features or any generalization of the novel features disclosed herein, whether or not the novel feature relates to the same invention as currently claimed in any claim or whether the novel feature alleviates any or all of the same technical problems as those alleviated by the present invention.

[0079] Features described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, individual features described in the context of individual embodiments for the sake of brevity may also be provided individually or in any suitable subcombination. Applicants hereby caution that new claims may be formulated based on such features and / or combinations of such features during the prosecution of this application or any further application derived therefrom.

[0080] For the sake of completeness, it is also provided that the term "comprising" does not exclude other elements or steps, the term "a" or "an" does not exclude a plurality, a single processor or other unit may satisfy the functions of several components described in the claims, and the figure marks in the claims should not be interpreted as limiting the scope of the claims. In addition, the word "may" is used in a permissive sense (i.e., meaning it is possible) rather than a mandatory sense (i.e., meaning it must). Similarly, the words "include", "including" and "includes" are meant to include but are not limited to. Unless otherwise stated, terms such as "first" and "second" are used to arbitrarily distinguish between the elements described by such terms. Therefore, these terms are not necessarily intended to indicate the temporal priority or other priority of such elements.

Claims

1. A scanning array radar device, characterized in that: Includes transmitter and receiver; The transmitter comprises a first lens-type scanning array transmitter unit, and the first lens-type scanning array transmitter unit comprises: an array of transmit antennas, each having a respective output feed having phase centers spaced apart along a first axis; a radio frequency (RF) integrated circuit (IC) configured to operate together with the transmit antenna array as a scanned array transmitter, and a lens configured to focus radiation from each of the output feeds; and The receiver comprises a first lens-type scanning array receiver unit, wherein the first lens-type scanning array receiver unit comprises: an array of receive antennas each having a respective input feed having phase centers spaced apart along a second axis; an RF IC configured to operate with the receive antenna array as a scanned array receiver, and A lens is configured to focus radiation reflected from the target toward each of the input feeds.

2. The scanning array radar device according to claim 1, wherein: wherein the transmitter is capable of functioning as a first transceiver, the transmit antenna array is a first transmit antenna array, and the first lens-scanned array transmitter unit is a first lens-scanned array transceiver unit, the first lens-scanned array transceiver unit further comprising: a second array of receive antennas, each having a respective input feed having phase centers spaced apart along a third axis, the third axis being parallel to and spaced apart from the first axis, and a second radio frequency integrated circuit (RF) configured to operate with the second receive antenna array as a scanned array receiver, and wherein the receiver is capable of functioning as a second transceiver, the receive antenna array is a first receive antenna array, and the first lens-scanned array receiver unit is a second lens-scanned array transceiver unit, the second lens-scanned array transceiver unit additionally comprising: a second array of transmit antennas, each having a respective output feed having phase centers spaced apart along a fourth axis, the fourth axis being parallel to and spaced apart from the second axis, and The second radio frequency integrated circuit (IC) is configured to operate together with the second transmit antenna array as a scanned array transmitter.

3. The scanning array radar device according to claim 2, characterized in that Also includes: A frequency synthesizer is configured to provide a common local oscillator signal to the first lens-type scanning array transmitter unit RFIC and the first lens-type scanning array receiver unit RFIC.

4. The scanning array radar device according to claim 3, wherein: Wherein the frequency synthesizer is further configured to provide the common local oscillator signal to the first lens scanning array transceiver unit second lens scanning array transmitter unit RF IC and the second lens scanning array transceiver unit second lens scanning array receiver unit RF IC.

5. The scanning array radar device according to claim 4, characterized in that The first axis is parallel to the second axis.

6. The scanning array radar device according to claim 5, characterized in that: wherein the second receive antenna array of the first lens-scanned array transceiver unit is configured to receive reflected radiation having a polarization orthogonal to the polarization of radiation transmitted by the first transmit antenna array of the first lens-scanned array transceiver unit; and wherein the first receive antenna array of the second lens-scanned array transceiver unit is configured to receive reflected radiation having a polarization orthogonal to a polarization of radiation transmitted by the second transmit antenna array of the second lens-scanned array transceiver unit.

7. The scanning array radar device according to claim 5, characterized in that: wherein the second receive antenna array of the first lens-scanned array transceiver unit is configured to receive radiation reflected by a target from radiation transmitted by the second transmit antenna array of the second lens-scanned array transceiver unit; and wherein the first receive antenna array of the second lens-scanned array transceiver unit is configured to receive radiation reflected by the target from radiation emitted by the first transmit antenna array of the first lens-scanned array transceiver unit.

8. The scanning array radar device according to claim 5, characterized in that Also includes: a first plurality of transceivers aligned with the first transceiver along the first axis, and A second plurality of transceivers is aligned with the second transceiver along the second axis.

9. The scanning array radar device according to claim 1, wherein: The first axis is orthogonal to the second axis.

10. The scanning array radar device according to claim 9, characterized in that: The lens of the emitter and the lens of each of the plurality of emitters each have a first focal length in the direction of the first axis and a second focal length in the direction of the second axis that is different from the first focal length.

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