A high-gain automotive millimeter-wave radar array antenna
Through the four-transmitter and four-receiving antenna array mode and the same-axis angle-feeding eight-yuan array design, the trade-offs of existing automotive millimeter-wave radar antennas in detection distance and field of view are solved, and high gain, low cost and High-resolution millimeter-wave radar system meets the needs of medium-range and long-range detection.
Patent Information
- Application Number
- CN202010946994.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-09-10
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2040-09-10
AI Technical Summary
When existing automotive millimeter-wave radar antennas achieve a longer detection distance and a larger field of view, the radiation characteristics are difficult to control, poor processing consistency, insufficient sub-lobe level suppression, poor angle resolution ability, and cannot meet the middle distance and distance. The requirement for distance detection.
Using four-transmitter and four-receiving antenna array mode, using eight-element array elements with equal amplitude angle feeding as the basic unit structure, the radiation and impedance matching characteristics of the antenna are improved through the design of microstrip line connection and rectangular patch, and the reflection cancellation groove is introduced. To reduce standing waves and sidelobes, optimize the antenna layout to improve gain and directionality.
Achieve high stability, miniaturization, low cost, high precision, high response speed and high resolution millimeter wave radar antennas, meeting the needs of medium-range and long-range detection, improving the sensitivity and angle resolution of the antenna, reducing the Cost and volume.
Smart Images
Figure CN112103645B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of vehicle-mounted millimeter-wave radar antennas, and in particular to a high-gain vehicle millimeter-wave radar array antenna. Background Art
[0002] In recent years, as an advanced driver assistance system technology necessary for breakthrough future driverless technology, automotive millimeter-wave radar technology is developing rapidly. Compared with optical cameras and lidars, automotive millimeter-wave radars have all-weather detection capabilities that are not afraid of rain, fog, dust and haze, and have long detection distances. They also have advantages such as high resolution and compact size. There are three main types of automotive radars according to distance: long-range, medium-range and short-range. Long-range radars usually use high-gain antennas to achieve longer detection needs, but their field of view (FOV) is also rapidly decreasing, so they usually can only cover the current lane and adjacent lanes. Medium-range radars usually use low-gain antennas in exchange for a larger FOV. Therefore, longer detection distances and larger field of view usually require corresponding trade-offs.
[0003] At present, the existing automotive millimeter-wave radar structures on the market mainly adopt the traditional microstrip line series-fed structure or series-fed array structure. The radiation characteristics of the antenna are difficult to control and the processing consistency is poor. The suppression of the sidelobe level needs to be improved, and the angular resolution capability is poor. The single TX-RX reflection path has the interference factor of the target echo amplitude fluctuation, which cannot meet the indicator requirements of the millimeter-wave radar system solutions for medium-range and long-range detection. Summary of the invention
[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a structure of a high-gain automotive millimeter-wave radar array antenna, which improves the antenna radiation and impedance matching characteristics by adopting a four-transmit and four-receive antenna array mode and using eight array elements with in-phase and equal-amplitude angle feeding as the basic unit structure.
[0005] The technical solution of the present invention is: a high-gain automotive millimeter-wave radar array antenna, comprising a millimeter-wave radar chip interface, a first receiving linear array antenna, a second receiving linear array antenna, a third receiving linear array antenna, a fourth receiving linear array antenna, a transceiver isolation linear array antenna, a first transmitting linear array antenna, a second transmitting linear array antenna, a third transmitting linear array antenna, and a fourth transmitting linear array antenna.
[0006] The beneficial effects of the present invention are as follows: the technical solution of the present invention has the advantages of high stability, miniaturization and low cost, the isolated linear array antenna improves the isolation between the transmitting and receiving channels, and its spatial layout is more reasonable. At the same time, it can meet the needs of high-precision, high-response speed and high-resolution millimeter-wave radar antennas, and can realize a low-cost, small-volume, high-performance millimeter-wave radar system solution for medium-range and long-range detection.
[0007] Its further technical solution is: the first to fourth input ends of the millimeter-wave radar chip interface are respectively connected to the input ends of the first receiving linear array antenna, the second receiving linear array antenna, the third receiving linear array antenna, and the fourth receiving linear array antenna through four 50-ohm microstrip lines of equal length; the first to fourth output ends of the millimeter-wave radar chip interface are respectively connected to the input ends of the first transmitting linear array antenna, the second transmitting linear array antenna, the third transmitting linear array antenna, and the fourth transmitting linear array antenna through four 50-ohm microstrip lines of equal length.
[0008] The beneficial effect of adopting the above further solution is that the use of four transmitting and receiving antennas with equal phases can improve the receiving sensitivity of the millimeter wave radar and facilitate the phase synchronization control of the radar.
[0009] A further technical solution is as follows: the first receiving linear array antenna, the second receiving linear array antenna, the third receiving linear array antenna, the fourth receiving linear array antenna, the transceiver isolation linear array antenna, the first transmitting linear array antenna, the second transmitting linear array antenna, the third transmitting linear array antenna, and the fourth transmitting linear array antenna are all composed of corner-fed eight-element linear array antennas; the input end of the corner-fed eight-element linear array antenna is connected to microstrip line feeders TL1, TL2, TL3, TL4, TL5, TL6, TL7, and TL8 in sequence from bottom to top in the vertical direction, and the dimensions thereof are all W0 mm wide and L0 mm long; the ends of the feeders TL1 to TL8 away from the input end are also Rectangular patches No. 1 to No. 8 are connected respectively, and rectangular patches No. 1, 3, 5, and 7 are arranged on the right side of the feed line, and rectangular patches No. 2, 4, 6, and 8 are arranged on the left side of the feed line. The dimensions of the rectangular patches are all W mm wide and L mm long, and the feeding positions are all fed at a 45° angle. A rectangular slot with an edge is reserved in the middle of each rectangular patch, and the dimensions of the rectangular slot with an edge are all dW mm wide and dL mm long. At the same time, a reflection cancellation slot with a width of dJ mm and a length of dH mm is reserved on the other side of the microstrip line at the 45° feeding end of each rectangular patch, and the length of the reflection cancellation slot from the 45° feeding end of the rectangular patch is dG mm.
[0010] The beneficial effect of adopting the above further scheme is that 8 equal-amplitude rectangular patches can form a linear antenna array, improve antenna gain and radiation directivity, and improve radar detection range and sensitivity; at the same time, a reflection cancellation slot is introduced on the transmission line, and the size of the slot controls the amplitude of the reflected echo. By adjusting the distance between the slot hole and the corner-feed patch, the phase difference between the two reflected waves is 180 degrees, thereby canceling the electromagnetic waves reflected back by the patch, improving the standing wave, and opening a rectangular slot in the middle of the rectangular patch to destroy the continuity of the current in the TM01 mode of the antenna to obtain single-mode transmission, so that the current propagates along the main polarization direction, reducing the side lobes of the antenna and improving the cross-polarization of the antenna. The patch antenna has low production cost, good antenna consistency, and is easy to install and integrate circuit functions.
[0011] The further technical solution is as follows: each antenna in the high-gain automotive millimeter-wave radar array antenna has two modes in layout arrangement. In the two modes, the first receiving linear array antenna, the second receiving linear array antenna, the third receiving linear array antenna, the fourth receiving linear array antenna, the transceiver isolation linear array antenna, the first transmitting linear array antenna, the second transmitting linear array antenna, the third transmitting linear array antenna, and the fourth transmitting linear array antenna are arranged in sequence from top to bottom in the plane layout; in the arrangement mode 1, the vertical spacing between adjacent antennas is 0.5λ, 0.5λ, 0.5λ, 0. 5λ, 0.5λ, 1.5λ, 0.5λ, λ mm, the input feed positions of the second and third transmitting linear array antennas are extended by 0.5λ mm in the horizontal direction than those of the other antennas; in arrangement mode 2, the vertical spacings between adjacent antennas are 0.5λ, 0.5λ, 0.5λ, 0.5λ, 1.5λ, λ, 0.5λ, 0.5λ mm, respectively, and the input feed positions of the second and third transmitting linear array antennas are extended by λ and 0.5λ mm in the horizontal direction than those of the other antennas, respectively, where λ is the length of an electromagnetic wavelength of an operating frequency.
[0012] The beneficial effect of adopting the above further scheme is that the distance between adjacent antennas is maintained at half of the electromagnetic wavelength of the working frequency (0.5λ mm), which can achieve precise phase control, improve the antenna radiation pattern when the four receiving antennas are combined into an antenna array, and increase the antenna gain; at the same time, the transmitting antenna array in the two arrangement modes meets the distribution conditions of the sparse matrix, which can improve the antenna aperture, make the antenna main beam narrower, and improve the angular resolution capability. At the same time, there are multiple TX-RX reflection paths, which improves the interference factor of the target echo amplitude fluctuation to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0014] Figure 1 The present invention provides a high-gain automotive millimeter-wave radar array antenna principle block diagram according to a specific embodiment of the present invention.
[0015] Figure 2 The present invention provides a circuit schematic diagram of a corner-fed eight-element linear array antenna in a high-gain automotive millimeter-wave radar array antenna provided by a specific embodiment of the present invention.
[0016] Figure 3 The present invention provides a circuit layout of a corner-fed eight-element linear array antenna in a high-gain automotive millimeter-wave radar array antenna provided by a specific embodiment of the present invention.
[0017] Figure 4 It is a layout diagram of an overall circuit arrangement mode 1 of a high-gain automotive millimeter-wave radar array antenna provided by a specific embodiment of the present invention.
[0018] Figure 5 It is a layout diagram of the second overall circuit arrangement mode of a high-gain automotive millimeter-wave radar array antenna provided by a specific embodiment of the present invention. DETAILED DESCRIPTION
[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without any creative work are within the scope of protection of the present invention.
[0020] A high-gain automotive millimeter-wave radar array antenna provided in this embodiment includes a millimeter-wave radar chip interface, a first receiving linear array antenna, a second receiving linear array antenna, a third receiving linear array antenna, a fourth receiving linear array antenna, a transceiver isolation linear array antenna, a first transmitting linear array antenna, a second transmitting linear array antenna, a third transmitting linear array antenna, and a fourth transmitting linear array antenna.
[0021] like Figure 1 , Figure 4 , Figure 5 As shown, the first to fourth input ends of the millimeter-wave radar chip interface are respectively connected to the input ends of the first receiving linear array antenna, the second receiving linear array antenna, the third receiving linear array antenna, and the fourth receiving linear array antenna through four 50-ohm microstrip lines of equal length; the first to fourth output ends of the millimeter-wave radar chip interface are respectively connected to the input ends of the first transmitting linear array antenna, the second transmitting linear array antenna, the third transmitting linear array antenna, and the fourth transmitting linear array antenna through four 50-ohm microstrip lines of equal length.
[0022] like Figure 2 and Figure 3As shown, the first receiving linear array antenna, the second receiving linear array antenna, the third receiving linear array antenna, the fourth receiving linear array antenna, the transceiver isolation linear array antenna, the first transmitting linear array antenna, the second transmitting linear array antenna, the third transmitting linear array antenna, and the fourth transmitting linear array antenna are all composed of corner-fed eight-element linear array antennas; the input end of the corner-fed eight-element linear array antenna is connected to microstrip line feeders TL1, TL2, TL3, TL4, TL5, TL6, TL7, and TL8 in sequence from bottom to top in the vertical direction, and the dimensions thereof are all W0 mm wide and L0 mm long; the ends of the feeders TL1 to TL8 away from the input end are also connected to Rectangular patches No. 1 to No. 8, rectangular patches No. 1, 3, 5, and 7 are arranged on the right side of the feed line, and rectangular patches No. 2, 4, 6, and 8 are arranged on the left side of the feed line. The dimensions of the rectangular patches are all W mm wide and L mm long, and the feeding positions are all fed at a 45° angle. A rectangular slot is reserved in the middle of each rectangular patch, and the dimensions of the rectangular slot are all dW mm wide and dL mm long. At the same time, a reflection cancellation slot with a width of dJ mm and a length of dH mm is reserved on the other side of the microstrip line at the 45° feeding end of each rectangular patch, and the length of the reflection cancellation slot from the 45° feeding end of the rectangular patch is dG mm.
[0023] like Figure 4 As shown, there are two modes in the layout arrangement of each antenna in the high-gain automotive millimeter-wave radar array antenna. In arrangement mode one, the first receiving linear array antenna, the second receiving linear array antenna, the third receiving linear array antenna, the fourth receiving linear array antenna, the transceiver isolation linear array antenna, the first transmitting linear array antenna, the second transmitting linear array antenna, the third transmitting linear array antenna, and the fourth transmitting linear array antenna are all arranged in sequence from top to bottom in the plane layout; the vertical spacing between adjacent antennas is 0.5λ, 0.5λ, 0.5λ, 0.5λ, 0.5λ, 1.5λ, 0.5λ, and λ mm respectively, and the input feed of the second transmitting linear array antenna and the third transmitting linear array antenna is extended by 0.5λ mm in the horizontal direction than that of the other antennas, where λ is the length of an electromagnetic wavelength of an operating frequency.
[0024] like Figure 5As shown, there are two modes in the layout of each antenna in the high-gain automotive millimeter-wave radar array antenna. In arrangement mode 2, the first receiving linear array antenna, the second receiving linear array antenna, the third receiving linear array antenna, the fourth receiving linear array antenna, the transceiver isolation linear array antenna, the first transmitting linear array antenna, the second transmitting linear array antenna, the third transmitting linear array antenna, and the fourth transmitting linear array antenna are arranged in sequence from top to bottom in the plane layout; the vertical spacing between adjacent antennas is 0.5λ, 0.5λ, 0.5λ, 0.5λ, 1.5λ, λ, 0.5λ, and 0.5λ mm, respectively, and the input feeding positions of the second transmitting linear array antenna and the third transmitting linear array antenna are extended by λ and 0.5λ mm respectively in the horizontal direction than the other antennas, where λ is the length of an electromagnetic wavelength of an operating frequency.
[0025] The above is a detailed introduction to a high-gain automotive millimeter-wave radar array antenna provided in an embodiment of the present invention. This article uses specific examples to illustrate the technical solution of the present invention. The above embodiments are only preferred embodiments of the invention and are not intended to limit the scope of protection of the present invention. For those skilled in the art, any changes or improvements that can be thought of within the technical scope of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A high-gain automotive millimeter-wave radar array antenna, characterized in that: It includes a millimeter wave radar chip interface, a first receiving linear array antenna, a second receiving linear array antenna, a third receiving linear array antenna, a fourth receiving linear array antenna, a transceiver isolation linear array antenna, a first transmitting linear array antenna, a second transmitting linear array antenna, a third transmitting linear array antenna, and a fourth transmitting linear array antenna; The first receiving linear array antenna, the second receiving linear array antenna, the third receiving linear array antenna, the fourth receiving linear array antenna, the transceiver isolation linear array antenna, the first transmitting linear array antenna, the second transmitting linear array antenna, the third transmitting linear array antenna, and the fourth transmitting linear array antenna are all composed of corner-fed eight-element linear array antennas; the input end of the corner-fed eight-element linear array antenna is connected to microstrip line feeders TL1, TL2, TL3, TL4, TL5, TL6, TL7, and TL8 in sequence from bottom to top in the vertical direction, and the dimensions thereof are all W0 mm wide and L0 mm long; the ends of the feeders TL1 to TL8 away from the input end are also connected to Rectangular patches No. 1 to No. 8, rectangular patches No. 1, 3, 5, 7 are arranged on the right side of the feed line, and rectangular patches No. 2, 4, 6, 8 are arranged on the left side of the feed line. The dimensions of the rectangular patches are all W mm wide and L mm long, and the feeding positions are all fed at a 45° angle. A rectangular groove is reserved in the middle of each rectangular patch, and the dimensions of the rectangular groove are all dW mm wide and dL mm long. At the same time, a reflection cancellation groove with a width of dJ mm and a length of dH mm is reserved on the other side of the microstrip line at the 45° feeding end of each rectangular patch, and the length of the reflection cancellation groove from the 45° feeding end of the rectangular patch is dG mm. There are two modes for the layout of each antenna in the high-gain automotive millimeter-wave radar array antenna. In the two modes, the first receiving linear array antenna, the second receiving linear array antenna, the third receiving linear array antenna, the fourth receiving linear array antenna, the transceiver isolation linear array antenna, the first transmitting linear array antenna, the second transmitting linear array antenna, the third transmitting linear array antenna, and the fourth transmitting linear array antenna are arranged in sequence from top to bottom in the plane layout; in the first arrangement mode, the vertical spacing between adjacent antennas is 0.5λ, 0.5λ, 0.5λ, 0.5λ, 0. 5λ, 1.5λ, 0.5λ, λ mm, the input feed of the second transmitting linear array antenna and the third transmitting linear array antenna is extended by 0.5λ mm in the horizontal direction than that of the other antennas; in arrangement mode 2, the vertical spacing between adjacent antennas is 0.5λ, 0.5λ, 0.5λ, 0.5λ, 1.5λ, λ, 0.5λ, 0.5λ mm, respectively, and the input feed positions of the second transmitting linear array antenna and the third transmitting linear array antenna are extended by λ and 0.5λ mm in the horizontal direction than those of the other antennas, respectively, where λ is the length of an electromagnetic wavelength of an operating frequency.
2. The high-gain automotive millimeter-wave radar array antenna according to claim 1, characterized in that: The first to fourth input ends of the millimeter-wave radar chip interface are respectively connected to the input ends of the first receiving linear array antenna, the second receiving linear array antenna, the third receiving linear array antenna, and the fourth receiving linear array antenna through four 50-ohm microstrip lines of equal length; the first to fourth output ends of the millimeter-wave radar chip interface are respectively connected to the input ends of the first transmitting linear array antenna, the second transmitting linear array antenna, the third transmitting linear array antenna, and the fourth transmitting linear array antenna through four 50-ohm microstrip lines of equal length.