Vehicle-mounted millimeter wave radar

Abstract

The embodiment of the utility model provides a vehicle-mounted millimeter-wave radar, which comprises a dielectric substrate, a radar chip assembled on the surface of the dielectric substrate, and two pairs of transmitting antennas and three pairs of receiving antennas which are arranged on the surface of the dielectric substrate in parallel and are connected to the radar chip through microstrip lines at the starting ends of the two pairs of transmitting antennas and the three pairs of receiving antennas, the transmitting antennas and the receiving antennas adopt the following sparse non-equidistant array layout and are provided with 8 to 14 equivalent receiving antennas; the distance between any two pairs of adjacent receiving antennas and the distance between two pairs of transmitting antennas are integer multiples of half-wavelength; and the sum of the intervals in the same layout is not less than 7 half-wavelengths and not greater than 13 half-wavelengths. According to the embodiment of the utility model, at least eight equivalent receiving antennas can be equivalent through two pairs of transmitting antennas and three pairs of receiving antennas, the number of the antennas is small, a low-cost radar chip can be adopted, the production cost is reduced, and the angular resolution of radar detection is ensured.

Description

Technical Field

[0001] Embodiments of the present utility model relate to the technical field of vehicle-mounted radars, and in particular to a vehicle-mounted millimeter-wave radar. Background Art

[0002] Vehicle-mounted millimeter-wave radars are usually used as angular detection radars for motor vehicles to implement functions such as DOA (door opening alert), LCA (lane change alert), BSD (blind spot detection), RCTA (rear cross traffic alert), etc., assisting drivers to make pre-judgments on various situations during driving and ensuring safe driving.

[0003] Existing vehicle-mounted millimeter-wave radars usually include 2 transmitting antennas and 4 receiving antennas with an equidistant design, and use the MIMO (multiple-in multiple-out) algorithm to equivalently obtain 8 equivalent receiving antennas. The optimal resolution that can be achieved is 2 / 8 radians, corresponding to an angular resolution of 14.3°. Since 6 antennas need to be used, the cost of the matching processing chip is relatively high, and the detection angular resolution is also limited. Summary of the Utility Model

[0004] The technical problem to be solved by the embodiments of the present utility model is to provide a vehicle-mounted millimeter-wave radar that can effectively reduce costs and ensure the angular resolution of radar detection.

[0005] To solve the above technical problem, the embodiments of the present utility model provide the following technical solutions: A vehicle-mounted millimeter-wave radar includes a dielectric substrate, a radar chip assembled on the surface of the dielectric substrate, and a transmitting antenna and a receiving antenna that are arranged parallel to each other on the surface of the dielectric substrate and both have their starting ends connected to the radar chip through microstrip lines. There are 2 transmitting antennas and 3 receiving antennas. The transmitting antenna and the receiving antenna adopt the following sparse non-equidistant array layout and have 8 to 14 equivalent receiving antennas: The distance between any two adjacent receiving antennas and the distance between the two transmitting antennas are both integer multiples of half a wavelength, and the sum of the distances in the same layout is not less than 7 half wavelengths and not greater than 13 half wavelengths.

[0006] Further, both the transmitting antenna and the receiving antenna are composed of linear array antennas of equal length, and the ends of each linear array antenna are flush with each other.

[0007] Further, the linear array antenna includes a main feeder and several radiation units connected to the main feeder. The radiation units are arranged in a staggered manner and have different sizes.

[0008] Further, the radiation units are distributed on both sides of the main feeder, and the phase difference between two adjacent radiation units is 180°. The areas of the radiation units on the same side of the main feeder decrease successively from the middle section of the main feeder to both ends.

[0009] Further, the radiation unit is of a rectangular structure.

[0010] Further, the microstrip lines connecting the sub-receiving antennas are bent and extended on the dielectric substrate and have equal lengths; the microstrip lines connecting the sub-transmitting antennas are bent and extended on the dielectric substrate and have equal lengths.

[0011] Further, the vehicle-mounted millimeter-wave radar further includes a first ground plane disposed on the surface of the dielectric substrate and having hollow holes respectively at positions corresponding to the radar chip and each microstrip line, and a predetermined gap is provided between the periphery of the radar chip and both sides of any part of each microstrip line and the edge of the hollow hole.

[0012] Further, the vehicle-mounted millimeter-wave radar further includes a second ground plane disposed on opposite sides of the dielectric substrate with respect to the first ground plane. Metal vias that sequentially penetrate the first ground plane, the dielectric substrate, and the second ground plane are evenly provided on the first ground plane on both sides along the line direction of each microstrip line, and metal posts are installed in the metal vias to electrically connect the first ground plane and the second ground plane.

[0013] After adopting the above technical solution, the embodiments of the present utility model at least have the following beneficial effects: The embodiments of the present utility model adopt 2 transmitting antennas and 3 receiving antennas, and the transmitting antennas and the receiving antennas adopt a sparse non-uniform spacing layout. Among them, the spacing between two adjacent receiving antennas and the spacing between the transmitting antennas are both set to be integer multiples of half-wavelength, and the sum of the spacings in the same layout is not less than 7 half-wavelengths and not greater than 13 half-wavelengths. Thus, 8 equivalent receiving antenna arrays can be equivalently obtained by using the MIMO algorithm, and the number of data vacancy positions can be effectively reduced. Then, the data of each equivalent receiving antenna position can be complemented by using the sparse position algorithm. Finally, the aperture number of the equivalent vehicle-mounted millimeter-wave radar can reach 8-14, that is, the number of equivalent receiving antennas can reach 8-14, and the effect of 8 equivalent receiving antennas achieved by 6 antennas with the existing two-transmitting and four-receiving and equal-spacing design can be achieved with a better number of antennas. Moreover, the number of antennas is small, and low-cost radar chips can be used, which is beneficial to reducing the production cost of the radar. In addition, since the number of obtained equivalent receiving antennas is not less than 8, it is beneficial to ensure the angular resolution of the radar detection. When necessary, up to 14 equivalent receiving antennas can be obtained by selecting the corresponding antenna layout, and its angular resolution can reach 8.19°. Compared with the angular resolution of the traditional design (14.3°), the improvement amplitude is very large. Description of the Drawings

[0014] Figure 1 It is a schematic plan view of an optional embodiment of the vehicle-mounted millimeter-wave radar of the present utility model.

[0015] Figure 2 It is a partial cross-sectional view perpendicular to the dielectric substrate and a microstrip line of an optional embodiment of the vehicle-mounted millimeter-wave radar of the present utility model.

[0016] Figure 3 It is the equivalent antenna position index obtained by processing the vehicle-mounted millimeter-wave radar of the present utility model through the MIMO algorithm. Detailed Embodiment

[0017] The following further details the present application in conjunction with the drawings and specific embodiments. It should be understood that the following illustrative embodiments and descriptions are only used to explain the present utility model and do not limit the present utility model. Moreover, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0018] Such as Figures 1-3As shown in the figure, an optional embodiment of the present utility model provides a vehicle-mounted millimeter-wave radar, which includes a dielectric substrate 1, a radar chip 2 assembled on the surface of the dielectric substrate 1, and a transmitting antenna 4a and a receiving antenna 4b that are arranged in parallel on the surface of the dielectric substrate 1 and both have their starting ends connected to the radar chip 2 through a microstrip line 3. There are 2 transmitting antennas 4a and 3 receiving antennas 4b. The transmitting antenna 4a and the receiving antenna 4b adopt the following sparse non-equidistant array layout and have 8 to 14 equivalent receiving antennas: the spacing between any two adjacent receiving antennas 4b and the spacing between the two transmitting antennas 4a are both integer multiples of half a wavelength, and the sum of the spacings in the same layout is not less than 7 half wavelengths and not greater than 13 half wavelengths.

[0019] In the embodiment of the present utility model, 2 transmitting antennas 4a and 3 receiving antennas 4b are adopted, and the transmitting antenna 4a and the receiving antenna 4b adopt a sparse non-equidistant layout. Among them, the spacing between any two adjacent receiving antennas 4b and the spacing between the transmitting antennas 4a are both set as integer multiples of half a wavelength, and the sum of the spacings in the same layout is not less than 7 half wavelengths and not greater than 13 half wavelengths. Thus, 8 equivalent receiving antenna arrays can be equivalent by using the MIMO algorithm, and the number of data vacancy positions can be effectively reduced. Then, the sparse position algorithm is used to complete the data at the positions of each equivalent receiving antenna. Finally, the aperture number of the vehicle-mounted millimeter-wave radar after equivalence can reach 8 - 14, that is, the number of equivalent receiving antennas can reach 8 - 14. It can achieve the effect of 8 equivalent receiving antennas with no less than the existing design of two transmitters and four receivers with equal spacing and 6 antennas, and the number of antennas is small, so low-cost radar chips can be used, which is beneficial to reducing the production cost of the radar. In addition, since the number of equivalent receiving antennas obtained is not less than 8, it is beneficial to ensure the angular resolution of radar detection. When necessary, up to 14 equivalent receiving antennas can be obtained by selecting the corresponding antenna layout, and its angular resolution can reach 8.19°. Compared with the angular resolution of the traditional design (14.3°), the improvement amplitude is very large.

[0020] In the specific implementation process, according to the transceiver signal frequency of the vehicle-mounted millimeter-wave radar, the value of the wavelength is obtained through the formula: wavelength = speed of light / frequency. Let: the spacing values between any two adjacent receiving antennas 4b be M times and N times of half a wavelength λ / 2 respectively, and the spacing between the two transmitting antennas 4a be P times of half a wavelength λ / 2. Then the number of equivalent receiving antennas A = M + N + P + 1. The corresponding relationship between the layout design of the transmitting antenna and the receiving antenna and the number of equivalent receiving antennas obtained can be referred to the following table:

[0021]

[0022] In another alternative embodiment of the present utility model, as Figure 1 shown, both the transmitting antenna 4a and the receiving antenna 4b are composed of linear array antennas 4 of equal length, and the tails of each pair of the linear array antennas 4 are flush with each other. In this embodiment, the transmitting antenna 4a and the receiving antenna 4b are linear array antennas 4 of equal length, and the tails of each linear array antenna 4 are arranged flush with each other, ensuring the equal-phase setting of the transmitting antenna 4a and the receiving antenna 4b, with good waveform symmetry in radar detection and reduced clutter interference.

[0023] In another alternative embodiment of the present utility model, as Figure 1 shown, the linear array antenna 4 includes a main feeder 41 and a plurality of radiation units 43 connected to the main feeder 41. The radiation units 43 are arranged in a staggered manner and have different sizes. In this embodiment, by arranging the radiation units 43 in a staggered manner, the density of the radiation units 43 connected in the length direction of the main feeder 41 can be increased. Each linear array antenna 4 has high radiation energy, increasing the farthest detection distance of the overall vehicle-mounted millimeter-wave radar. Also, by setting the sizes of the radiation units 43 to be different, current weighting is achieved, making the phases of the signals entering the radiation units 43 consistent, reducing the sidelobe level, and improving the gain of the linear array antenna 4.

[0024] In another alternative embodiment of the present utility model, as Figure 1 shown, the radiation units 43 are distributed on both sides of the main feeder 41, and the phases of two adjacent radiation units 43 differ by 180°. The areas of the radiation units 43 on the same side of the main feeder 41 decrease successively from the middle section of the main feeder 41 towards both ends. In this embodiment, by distributing the radiation units 43 on both sides of the main feeder 41 and making the phases of two adjacent radiation units 43 differ by 180°, the lateral radiation range of the linear array antenna 4 is increased. Also, the areas of the radiation units 43 on the same side of the main feeder 41 decrease successively from the middle section of the main feeder 41 towards both ends, which is used to ensure the consistency of the phases of the signals entering the radiation units 43, reduce the sidelobe level, and improve the gain of the linear array antenna 4.

[0025] In another alternative embodiment of the present utility model, as Figure 1 shown, the radiation unit 43 is of a rectangular structure. In this embodiment, the radiation unit 43 of a rectangular structure is adopted, so that the radiation unit 43 of the linear array antenna 4 has the maximum radiation in the broadside direction. It can be understood that in specific implementation, the radiation unit 43 can also be designed as a circular structure, an elliptical structure, a triangular structure, etc. according to actual needs.

[0026] In another alternative embodiment of the present utility model, as Figure 1As shown, the microstrip lines 3 connecting the sub-receiving antennas 4b are bent and extended on the dielectric substrate 1 and have equal lengths; the microstrip lines 3 connecting the sub-transmitting antennas 4a are bent and extended on the dielectric substrate 1 and have equal lengths. In this embodiment, by bending the microstrip lines 3 for routing and making equal-length designs corresponding to the transmitting antennas 4a and receiving antennas 4b respectively, equal-phase designs for each sub-receiving antenna 4b and each sub-transmitting antenna 4a are achieved, the waveform symmetry of radar detection is good, and clutter interference is reduced.

[0027] In another alternative embodiment of the present utility model, as Figure 1 and Figure 2 shown, the vehicle-mounted millimeter-wave radar antenna further includes a first ground plane 5 disposed on the surface of the dielectric substrate 1 and having hollow holes 50 respectively provided at positions corresponding to the radar chip 2 and each of the microstrip lines 3, and a predetermined gap 52 is provided between the periphery of the radar chip 2 and the edges of the hollow holes 50 on both sides of any part of each microstrip line 3. In this embodiment, by adding the first ground plane 5, forming the microstrip lines 3 inside the first ground plane 5, and further providing the hollow holes 50 and the predetermined gap 52, electromagnetic waves can be effectively restricted within the hollow holes 50 of the first ground plane 5, reducing losses and avoiding the influence on other external electromagnetic components.

[0028] In another alternative embodiment of the present utility model, as Figure 1 and Figure 2 shown, the vehicle-mounted millimeter-wave radar further includes a second ground plane 6 disposed on opposite sides of the dielectric substrate 1 with the first ground plane 5. Metal vias 54 that sequentially penetrate the first ground plane 5, the dielectric substrate 1, and the second ground plane 6 are evenly provided on the first ground plane 5 on both sides along the line direction of each microstrip line 3, and metal posts 56 are installed in the metal vias 54 to electrically connect the first ground plane 5 and the second ground plane 6. In this embodiment, by providing the metal vias 54 on both sides along the line direction of the microstrip line 3 and electrically connecting the first ground plane 5 and the second ground plane 6 through the metal posts 56, the grounding of the first ground plane 5 is achieved, and the grounding property on both sides of the line can be enhanced.

[0029] The embodiments of the present utility model have been described above in conjunction with the accompanying drawings. However, the present utility model is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present utility model, those of ordinary skill in the art can also make many variations without departing from the spirit and scope protected by the claims of the present utility model. These all fall within the protection scope of the present utility model.

Claims

1. A vehicle-mounted millimeter-wave radar, comprising a dielectric substrate, a radar chip assembled on the surface of the dielectric substrate, and a transmitting antenna and a receiving antenna which are arranged in parallel on the surface of the dielectric substrate and both have starting ends connected to the radar chip through microstrip lines, characterized in that, There are 2 transmitting antennas and 3 receiving antennas. The transmitting antennas and the receiving antennas adopt the following sparse non-uniform array layout and have 8 to 14 equivalent receiving antennas: The spacing between any two adjacent receiving antennas and the spacing between the two transmitting antennas are both integer multiples of half wavelength, and the sum of the spacings in the same layout is not less than 7 half wavelengths and not more than 13 half wavelengths.

2. The vehicle-mounted millimeter-wave radar according to claim 1, wherein Both the transmitting antennas and the receiving antennas are composed of linear array antennas of equal length, and the ends of each linear array antenna are flush with each other.

3. The vehicle-mounted millimeter-wave radar according to claim 2, characterized in that The linear array antenna includes a main feeder and a plurality of radiation units connected to the main feeder. The radiation units are arranged in a staggered manner and have different sizes.

4. The vehicle-mounted millimeter-wave radar according to claim 3, wherein The radiation units are distributed on both sides of the main feeder, and the phase difference between two adjacent radiation units is 180°. The areas of the radiation units on the same side of the main feeder decrease sequentially from the middle section of the main feeder to both ends.

5. The vehicle-mounted millimeter-wave radar according to claim 3, wherein The radiation unit is of a rectangular structure.

6. The vehicle-mounted millimeter-wave radar according to claim 1, characterized in that, The microstrip lines connecting each receiving antenna bend and extend on the dielectric substrate and are of equal length; The microstrip lines connecting each transmitting antenna bend and extend on the dielectric substrate and are of equal length.

7. The vehicle-mounted millimeter-wave radar according to claim 1, characterized in that The vehicle-mounted millimeter-wave radar further includes a first ground plane disposed on the surface of the dielectric substrate and having hollow holes at positions corresponding to the radar chip and each microstrip line, and a predetermined gap is provided between the periphery of the radar chip and the edges of the hollow holes on both sides of any part of each microstrip line.

8. The vehicle-mounted millimeter-wave radar according to claim 7, wherein The vehicle-mounted millimeter-wave radar further includes a second ground plane disposed on opposite sides of the dielectric substrate with respect to the first ground plane. Metal vias that sequentially penetrate the first ground plane, the dielectric substrate, and the second ground plane are evenly provided on the first ground plane on both sides along the line direction of each microstrip line, and metal posts are installed in the metal vias to electrically connect the first ground plane and the second ground plane.

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