Dual-chip 4D vehicle-mounted millimeter wave radar antenna array

Abstract

The utility model relates to the technical field of millimeter-wave radars, in particular to a double-chip 4D vehicle-mounted millimeter-wave radar antenna array, which comprises eight receiving antenna array elements and six transmitting antenna array elements. Four array elements in the receiving antenna array elements are horizontally arranged at equal intervals, the interval is four half wavelengths, and the last four array elements and the transmitting antenna array element form an equivalent pitching array. According to the utility model, through the horizontal equidistant layout of the receiving antennas and the grouping three-column pitching array layout design of the transmitting antennas, the equivalent aperture in the horizontal direction can be effectively expanded; the equivalent aperture is synthesized through two groups of equivalent arrays in the pitching direction, which is obviously superior to the traditional uniform array; the non-half-wavelength integral multiple emission pitching coordinate design breaks through the limitation of uniform array arrangement, the aperture is flexibly expanded, and meanwhile, the in-phase superposition interference of a bumper reflection signal is reduced.

Description

A dual-chip 4D vehicle-mounted millimeter-wave radar antenna array Technical Field

[0001] This utility model relates to the field of millimeter-wave radar technology, specifically to a dual-chip 4D vehicle-mounted millimeter-wave radar antenna array. Background Technology

[0002] Millimeter-wave radar has become a primary sensor in ADAS systems due to its long detection range, high detection accuracy, and strong angular resolution. Traditional automotive millimeter-wave radar has relatively low performance requirements, with very low demands on elevation angle measurement performance and resolution. However, 4D millimeter-wave imaging radar places higher demands on radar detection performance. It not only requires higher range and velocity resolution, but more importantly, it places higher demands on radar angular measurement performance (such as horizontal angle measurement accuracy, angular resolution, elevation angle measurement accuracy and resolution, and the ability to distinguish between large and small targets). Consequently, the radar system design is more complex.

[0003] The Chinese utility model patent with announcement number CN217468812U, entitled "A Vehicle-Mounted 4D Millimeter-Wave Radar Antenna Array," discloses a configuration including 12 transmitting elements and 16 receiving elements. The 16 receiving elements are divided into two groups of eight elements each, with the two groups positioned in the first and sixth rows of the antenna array, respectively. The 12 transmitting elements are divided into four groups of two, six, two, and two elements each, with the four groups positioned in the second to fifth rows of the antenna array, respectively.

[0004] The antenna array in the above scheme is small in size and has high angular resolution, making it valuable for market applications.

[0005] However, the angular resolution of radar is determined by the radar aperture, and the spacing between array elements determines the state of the sidelobes. The traditional antennas in the above schemes use uniform arrays and minimum redundancy arrays. This array arrangement results in an excessively low aperture, insufficient angular resolution, and low detection efficiency in multi-target situations.

[0006] Antenna layout design, as a crucial component of millimeter-wave radar systems, has always been a key focus in millimeter-wave radar design. Antenna layout design must consider both the horizontal and vertical angular measurement performance of the millimeter-wave radar and the stability of radar detection. This places demands on the antenna's coordinate position: on the one hand, it must facilitate the routing of the antenna feed line without interference; on the other hand, it must minimize the loss of the antenna feed line. Furthermore, considering that most automotive millimeter-wave radars are mounted behind the bumper, the bumper inevitably causes some interference to the radar signal, leading to a decrease in point cloud quality. Therefore, the antenna layout design must also consider how to reduce the bumper's interference with the radar.

[0007] To address these issues, a dual-chip 4D vehicle-mounted millimeter-wave radar antenna array is proposed. Summary of the Invention

[0008] Technical problems to be solved

[0009] In view of the above-mentioned shortcomings of the existing technology, the present invention provides a dual-chip 4D vehicle-mounted millimeter-wave radar antenna array, which can effectively solve the problem of unreasonable antenna array design in the existing millimeter-wave radar.

[0010] Technical solution

[0011] To achieve the above objectives, this utility model provides the following technical solution:

[0012] This utility model provides a dual-chip 4D vehicle-mounted millimeter-wave radar antenna array, including 8 receiving antenna elements and 6 transmitting antenna elements; four of the receiving antenna elements are arranged horizontally at equal intervals, with a spacing of 4.5 wavelengths, and the latter four elements and the transmitting antenna elements form an equivalent elevation array; the 6 transmitting antenna elements are divided into two groups of three columns of equally spaced elements in the elevation direction, with a spacing of 4.5 wavelengths between the transmitting antenna elements in each group; wherein, the equally spaced elements in the transmitting antenna elements and the latter four elements of the receiving antenna elements form two groups of equivalent elevation arrays for expanding the elevation aperture.

[0013] Furthermore, the elevation coordinates of the six transmitting antenna elements are 9 half-wavelengths, 11.9 half-wavelengths, 13.8 half-wavelengths, 17.5 half-wavelengths, 23.8 half-wavelengths, and 25 half-wavelengths, respectively.

[0014] Furthermore, the horizontal coordinates of the eight receiving antenna elements are 0, 9 half-wavelengths, 22 half-wavelengths, 25 half-wavelengths, 28 half-wavelengths, 32 half-wavelengths, 36 half-wavelengths, and 40 half-wavelengths, while the elevation coordinates are all 0.

[0015] Furthermore, the horizontal coordinates of the six transmitting antenna elements are 0, 4 half-wavelengths, 8 half-wavelengths, 0, 4 half-wavelengths, 8 half-wavelengths, and the elevation coordinates are 9 half-wavelengths, 11.9 half-wavelengths, 13.8 half-wavelengths, 17.5 half-wavelengths, 23.8 half-wavelengths, and 25 half-wavelengths.

[0016] Furthermore, the equivalent pitch array includes two sets of pitch arrays distributed left and right for auxiliary verification of pitch angle measurement. One set of pitch arrays consists of six transmitting array elements with close spacing, and the other set of pitch arrays consists of four receiving array elements.

[0017] Furthermore, the two sets of equivalent elevation arrays of the transmitting antenna array are respectively connected to the first monolithic microwave integrated circuit and the second monolithic microwave integrated circuit, and the four array elements of the receiving antenna array that are equally distributed are connected to the first monolithic microwave integrated circuit, and the latter four array elements are connected to the second monolithic microwave integrated circuit.

[0018] Furthermore, the antenna array adopts an L-shaped layout, with the antenna elements in the horizontal and elevation directions orthogonally distributed.

[0019] Beneficial effects

[0020] The technical solution provided by this utility model has the following advantages compared with the known public technology:

[0021] This invention effectively expands the equivalent aperture in the horizontal direction through the horizontally equidistant layout of the receiving antenna and the grouped three-column elevation array layout of the transmitting antenna; the equivalent aperture in the elevation direction is synthesized by two sets of equivalent arrays, which is significantly better than the traditional uniform array.

[0022] The design of transmit elevation coordinates that are not integer multiples of half wavelength breaks the limitations of uniform array layout, flexibly expands the aperture, and reduces the in-phase superposition interference of bumper reflected signals.

[0023] The equivalent elevation array adopts a left-right distributed design. The six-element main array on the left provides high-density sampling, while the four-element auxiliary verification channel on the right uses redundant data cross-verification to suppress multipath interference and noise effects and improve angle measurement stability.

[0024] Two sets of auxiliary verification channels can effectively reduce the false judgment rate in complex scenarios (such as tunnels and multiple vehicles traveling in parallel);

[0025] The two sets of three-row array elements of the transmitting antenna are connected to the first and second monolithic microwave integrated circuits, and the first four and last four array elements of the receiving antenna are connected to the corresponding chips to distribute the signal processing pressure and avoid overloading of a single chip.

[0026] The horizontal and vertical antennas are arranged orthogonally to maximize the use of PCB space and reduce component stacking; the transmitting antenna is moved upward to avoid the bumper obstruction area and reduce metal reflection interference. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 is a schematic diagram of the actual array position of the millimeter-wave radar antenna in an embodiment of this utility model;

[0029] Figure 2 is a partial layout diagram of the millimeter-wave radar elevation virtual channel in an embodiment of this utility model.

[0030] The labels in the diagram represent: 1. Receiving antenna array element; 2. Transmitting antenna array element; 3. Second monolithic microwave integrated circuit; 4. First monolithic microwave integrated circuit. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0032] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0033] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above, diagonally above, or on the surface of the second feature, indicating that the second feature is supported and fixed by the first feature, or simply indicating that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicating that the first feature is at a lower horizontal level than the second feature.

[0034] In the description of this embodiment, the terms "upper," "lower," "left," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0035] The present invention will be further described below with reference to the embodiments.

[0036] Example:

[0037] This solution proposes a dual-chip 4D vehicle-mounted millimeter-wave radar antenna array, as shown in Figures 1-2.

[0038] The dual-chip 4D vehicle-mounted millimeter-wave radar antenna array in this embodiment mainly includes 8 receiving antenna elements 1 and 6 transmitting antenna elements 2.

[0039] The four elements in the receiving antenna array 1 are arranged horizontally at equal intervals, with a spacing of 4.5 wavelengths. The last four elements and the transmitting antenna array 2 form an equivalent elevation array.

[0040] The six transmitting antenna elements 2 are divided into two groups of three columns of equally spaced elements in the elevation direction, and the spacing between the transmitting antenna elements 2 in each group of equally spaced elements is 4.5 wavelengths.

[0041] As shown in Figure 1, the antenna position is defined with the horizontal direction as the y-axis and the elevation direction as the z-axis, with the unit being half a wavelength:

[0042] Coordinates of the 8 receiving antenna elements 1:

[0043] The horizontal coordinates are 0, 9 half-wavelengths, 22 half-wavelengths, 25 half-wavelengths, 28 half-wavelengths, 32 half-wavelengths, 36 half-wavelengths, and 40 half-wavelengths. The last four array elements (28-40 half-wavelengths) are equally spaced (4 half-wavelengths), while the spacing between the first four array elements (0-25 half-wavelengths) gradually increases (4 half-wavelengths to 8 half-wavelengths), which are used to synthesize an equivalent elevation array with the transmitting antenna.

[0044] All receiving array elements in the elevation direction coordinate are 0, forming a horizontal linear array;

[0045] Coordinates of the 6 transmitting antenna arrays:

[0046] The horizontal coordinates are: repeating pattern 0, 4 half-wavelengths, 8 half-wavelengths, with the two groups of three-column array elements having the same horizontal position, forming a symmetrical distribution.

[0047] The pitch coordinates are: 9 half-wavelengths, 11.9 half-wavelengths, 13.8 half-wavelengths (first group) and 17.5 half-wavelengths, 23.8 half-wavelengths, 25 half-wavelengths (second group). Non-half-wavelength integer multiple spacing (e.g., 11.9 half-wavelengths ≈ 3λ / 4) reduces in-phase interference of bumper reflected signals.

[0048] Thus, the equally spaced array elements in transmitting antenna element 2 and the last four array elements in receiving antenna element 1 form two sets of equivalent elevation arrays for expanding the elevation aperture.

[0049] In this embodiment, the eight array elements of the receiving channel form a linear array, and the theoretical aperture resolution of the azimuth angle is about 2.86 degrees, which is obtained by the formula λ / (D*cos(θ)), where λ is the wavelength and D is the antenna aperture. Compared with the existing publicly available technical solutions, the azimuth and elevation angle resolutions are significantly improved.

[0050] In this embodiment, the theoretical resolution of the combined aperture of the six transmitting antennas in the elevation direction is approximately 7.1 degrees, which is obtained by the formula λ / (D*cos(θ)), where λ is the wavelength and D is the antenna aperture. Compared with the existing publicly available technical solutions, the resolution of the azimuth and elevation angles is significantly improved.

[0051] Based on MIMO technology, 6 transmit antennas and 8 receive antennas are combined to generate 48 virtual channels (6×8).

[0052] Specifically as follows:

[0053] The left-side main elevation array is formed by combining the first group of transmitting antennas (9d, 11.9d, 13.8d) with the four array elements behind the receiving antenna (28d-40d), creating a six-element non-uniform elevation array with an equivalent aperture extended to 25d (calculation formula: D = 25d). The resolution θ ≈ λ / (2 × 25d) = 7.1°.

[0054] Right auxiliary array: The four array elements (28d-40d) behind the receiving antenna independently form a four-element elevation verification channel. By comparing the output signals of the main and auxiliary arrays, abnormal data (such as multipath interference) is eliminated, which improves the robustness of the angle measurement signal.

[0055] The equivalent elevation array includes two sets of elevation arrays distributed left and right and used to assist in verifying the elevation angle measurement. One set of elevation arrays consists of six closely spaced transmitting array elements, and the other set of elevation arrays consists of four receiving array elements.

[0056] Furthermore, as shown in Figure 1, the two sets of equivalent elevation arrays of the transmitting antenna array element 2 are connected to the first monolithic microwave integrated circuit 4 and the second monolithic microwave integrated circuit 3, respectively. The four array elements of the receiving antenna array element 1 that are evenly distributed are connected to the first monolithic microwave integrated circuit 4, and the latter four array elements are connected to the second monolithic microwave integrated circuit 3.

[0057] In this embodiment, the antenna layout has four equally spaced elements in the receiving antenna array 1, with a spacing of 4.5 wavelengths. The transmitting antenna array 2 is divided into three columns in elevation, with a spacing of 4.5 wavelengths in each column. These three columns of transmitting antenna array 2 and the last four equally spaced elements in the receiving antenna array 1 form two sets of equivalent elevation arrays. On the left side of the two equivalent elevation arrays, there is a six-element elevation array with close spacing, and on the right side, there is a four-element elevation array as an auxiliary verification, which effectively improves the elevation angle measurement capability. The six-element main array on the left provides high-density sampling, and the four-element auxiliary verification channel on the right uses redundant data cross-verification to suppress multipath interference and noise, thereby improving the angle measurement stability. The formed auxiliary verification channel can effectively reduce the misjudgment rate in complex scenarios (such as tunnels and multiple vehicles traveling in parallel).

[0058] As shown in Figure 1, the two three-row equally spaced array elements of the transmitting antenna array 2 are electrically connected to the first monolithic microwave integrated circuit 4 and the second monolithic microwave integrated circuit 3, respectively. The first four array elements of the receiving antenna array 1 are connected to the first monolithic microwave integrated circuit 4, and the last four equally spaced array elements of the receiving antenna array 1 are connected to the second monolithic microwave integrated circuit 3.

[0059] Specifically:

[0060] Transmitting antenna array element 2: The first group of transmitting antenna array elements 2 (9 half-wavelengths, 11.9 half-wavelengths, 13.8 half-wavelengths) is connected to the first microwave integrated circuit, and the second group (17.5 half-wavelengths, 23.8 half-wavelengths, 25 half-wavelengths) is connected to the second microwave integrated circuit.

[0061] Receiving antenna element 1: The first four receiving antenna elements 1 (0-25 half wavelengths) are connected to the first microwave integrated circuit, and the last four elements (28-40 half wavelengths) are connected to the second microwave integrated circuit.

[0062] Thus, this dual-chip design uses a shared clock source and synchronous trigger signal to ensure consistent transmission pulse timing and phase alignment of received signal sampling, avoiding phase deviation during virtual channel synthesis.

[0063] In this embodiment of the utility model, the virtual layout of the designed transceiver antenna will synthesize 6 equivalent 8-element arrays in the horizontal direction and 2 equivalent 6-element arrays in the elevation direction.

[0064] Horizontal antenna element spacing: 9.5 wavelengths, 13.5 wavelengths, 3.5 wavelengths, 3.5 wavelengths, 4.5 wavelengths, 4.5 wavelengths, 4.5 wavelengths;

[0065] Elevation antenna element spacing: 2.9 half wavelengths, 1.9 half wavelengths, 3.7 half wavelengths, 6.3 half wavelengths, 1.2 half wavelengths.

[0066] In this embodiment of the invention, the reconfigured antenna layout improves the robustness of the angle measurement signal and makes effective use of the signal channel.

[0067] Furthermore, the designed antenna layout employs a non-half-wavelength spacing in the elevation direction and is shifted upwards. This reduces the impact of the car bumper on radar interference and allows for more flexible antenna layout design by using a non-half-wavelength integer multiple spacing design.

[0068] Since the antenna coordinates on the bumper mounting plane are usually less than 5.5 wavelengths, the L-shaped antenna layout in this embodiment is reasonable and compact, providing enough space for the placement of the RF chip. This reduces the difficulty of component stacking on the PCB to a certain extent, making the PCB layout more flexible and the RF routing relatively simple and smooth.

[0069] Specifically:

[0070] Horizontal branch: The receiving antenna array element 1 is arranged along the y-axis (horizontal direction), covering the azimuth range of -85° to +85°.

[0071] Pitch branch: The transmitting antenna element 2 is offset upward along the z-axis (pitch direction) to cover the pitch angle range of -15° to +15°.

[0072] Therefore, this orthogonal arrangement of the horizontal and vertical branches can effectively reduce the coupling between antennas, and the design of the transmitting antenna array elements with 2z coordinates of 9d-25d can avoid the bumper mounting plane and reduce the intensity of metal reflection signals.

[0073] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of this utility model.

Claims

1. A dual-chip 4D vehicle-mounted millimeter-wave radar antenna array, characterized in that, include: Eight receiving antenna elements (1) and six transmitting antenna elements (2); The four elements of the receiving antenna array (1) are arranged horizontally at equal intervals, with a spacing of 4.5 wavelengths. The last four elements and the transmitting antenna array (2) form an equivalent elevation array. The six transmitting antenna array elements (2) are divided into two groups of three columns of equally spaced array elements in the elevation direction. The spacing between the transmitting antenna array elements (2) in each group of equally spaced array elements is 4.5 wavelengths. The equally spaced array elements in the transmitting antenna array elements (2) and the last four elements of the receiving antenna array elements (1) form two groups of equivalent elevation arrays for expanding the elevation aperture.

2. The dual-chip 4D vehicle-mounted millimeter-wave radar antenna array according to claim 1, characterized in that, The elevation coordinates of the six transmitting antenna elements (2) are 9 half-wavelengths, 11.9 half-wavelengths, 13.8 half-wavelengths, 17.5 half-wavelengths, 23.8 half-wavelengths, and 25 half-wavelengths, respectively.

3. The dual-chip 4D vehicle-mounted millimeter-wave radar antenna array according to claim 1, characterized in that, The horizontal coordinates of the eight receiving antenna elements (1) are 0, 9 half-wavelengths, 22 half-wavelengths, 25 half-wavelengths, 28 half-wavelengths, 32 half-wavelengths, 36 half-wavelengths, and 40 half-wavelengths, and the elevation coordinates are all 0.

4. The dual-chip 4D vehicle-mounted millimeter-wave radar antenna array according to claim 1, characterized in that, The horizontal coordinates of the six transmitting antenna elements (2) are 0, 4 half-wavelength, 8 half-wavelength, 0, 4 half-wavelength, 8 half-wavelength, and the elevation coordinates are 9 half-wavelength, 11.9 half-wavelength, 13.8 half-wavelength, 17.5 half-wavelength, 23.8 half-wavelength, 25 half-wavelength.

5. The dual-chip 4D vehicle-mounted millimeter-wave radar antenna array according to claim 1, characterized in that, The equivalent elevation array includes two sets of elevation arrays distributed on the left and right and used to assist in verifying the elevation angle measurement. One set of elevation arrays consists of six closely spaced transmitting antenna elements (2), and the other set of elevation arrays consists of four receiving antenna elements (1).

6. The dual-chip 4D vehicle-mounted millimeter-wave radar antenna array according to claim 1, characterized in that, The two sets of equivalent elevation arrays of the transmitting antenna array element (2) are respectively connected to the first monolithic microwave integrated circuit (4) and the second monolithic microwave integrated circuit (3). The four array elements of the receiving antenna array element (1) that are equally distributed are connected to the first monolithic microwave integrated circuit (4), and the latter four array elements are connected to the second monolithic microwave integrated circuit (3).

7. The dual-chip 4D vehicle-mounted millimeter-wave radar antenna array according to claim 1, characterized in that, The antenna array adopts an L-shaped layout, with the antenna elements in the horizontal and elevation directions orthogonally distributed.

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