Millimeter wave radar antenna and radar apparatus

Abstract

The utility model provides a millimeter wave radar antenna and radar equipment, and belongs to the technical field of antennae, and the millimeter wave radar antenna comprises a substrate which comprises multiple layers of dielectric plates and multiple layers of metal plates, the multiple layers of dielectric plates and the multiple layers of metal plates are alternately stacked to form a laminated structure, and the substrate is provided with a first surface and a second surface, the first surface is provided with a slot array, the second surface is provided with a feed port, and the side wall of each slot is covered with a layer of metal material; the top and the bottom of the metal cavity are formed by metal plates of corresponding layers of the laminated structure, the side wall of the metal cavity is covered with a layer of metal material, and the slot array and the feed port are communicated in the metal cavity so that the slot array can emit signals output by the feed port and receive signals scattered back by a target. The millimeter-wave radar antenna solves the problems that in an existing millimeter-wave radar antenna, the cost of a high-frequency plate is too high, and the size of radar equipment is too large, and improves the performance and cost effectiveness of an antenna system.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to a millimeter wave radar antenna and radar equipment. Background Art

[0002] In millimeter-wave radar antenna design, patch antennas are usually printed on high-frequency boards. Since the cost of high-frequency boards is relatively high and accounts for a large proportion of the product cost, many products use cascaded chip solutions to improve the performance of millimeter-wave radars. However, the use of cascaded chip solutions has led to a gradual increase in the size of radar equipment, which has also increased the cost of high-frequency boards. Therefore, in order to reduce costs and maintain performance, other solutions need to be explored to avoid the problems of high-frequency board costs and large radar equipment. Utility Model Content

[0003] The present application provides a millimeter wave radar antenna and a radar device, which are used to solve the problems of high cost of high frequency plates in existing millimeter wave radar antennas and large size of radar devices.

[0004] In a first aspect, the present application provides a millimeter wave radar antenna, the millimeter wave radar antenna comprising:

[0005] A substrate, comprising a multi-layer dielectric plate and a multi-layer metal plate, wherein the multi-layer dielectric plate and the multi-layer metal plate are alternately stacked to form a laminated structure, wherein the substrate has a first surface and a second surface opposite thereto, wherein the first surface is provided with a slot array, and the second surface is provided with a feeding port, and the side wall of each slot in the slot array is covered with a layer of metal material;

[0006] A metal cavity, the top and bottom of the metal cavity are formed by metal plates of corresponding layers of the laminated structure, the side walls of the metal cavity are covered with a layer of metal material, and the slot array and the feeding port are connected in the metal cavity so that the slot array transmits the signal output by the feeding port and receives the signal scattered back by the target.

[0007] In one embodiment of the present application, the stacked structure includes, in sequence along a direction away from the first surface, a first layer structure consisting of a first dielectric plate and a second layer structure consisting of a first metal plate and a second dielectric plate, and each gap in the gap array penetrates the first dielectric plate and the first metal plate.

[0008] In one embodiment of the present application, the millimeter wave radar antenna further includes a plurality of isolation cavities, each isolation cavity being located at one end of each layer of metal plate close to the side wall of the metal cavity so that the metal plate has no electrical connection with the side wall of the metal cavity.

[0009] In one embodiment of the present application, the metal cavity is a rectangular cavity, and the wavelength propagated in the waveguide is Where λ represents the wavelength of electromagnetic waves propagating in free space, W g Represents the wide side of the metal cavity.

[0010] In one embodiment of the present application, the length of each gap and the distance between two adjacent gaps are approximately equal to λ g / 2.

[0011] In one embodiment of the present application, the shortest distance from the center point of each of the first and last gaps to the side wall of the metal cavity along the length direction of the metal cavity is λ g / Integer multiple of 4.

[0012] In an embodiment of the present application, the metal cavity is not grounded.

[0013] In one embodiment of the present application, the dielectric plate is a glass fiber reinforced epoxy resin substrate plate.

[0014] In one embodiment of the present application, the vertical distance from the gap in the middle of the metal cavity to the center line of the metal cavity is the largest and gradually decreases toward both ends.

[0015] In a second aspect, the present application further provides a radar device, comprising a millimeter wave radar antenna as described in any one of the first aspects.

[0016] The millimeter wave radar antenna and radar device provided in the present application can realize the compactness and high integration of the antenna system by adopting a laminated structure and a metal cavity design, thereby effectively reducing the manufacturing cost and reducing the overall volume. In addition, the design of the metal cavity and the slot array helps to improve the radiation characteristics and frequency response of the antenna, thereby improving the performance of the radar device in the millimeter wave frequency band.

[0017] Therefore, the present application can solve the problems of high cost of high-frequency plates in existing millimeter-wave radar antennas and large size of radar equipment, and improve the performance and cost-effectiveness of the antenna system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 is a stereogram of a millimeter wave radar antenna provided in an embodiment of the present application;

[0020] Figure 2 yes Figure 1 A partial enlarged view of the laminated structure;

[0021] Figure 3 is a bottom view of a millimeter wave radar antenna provided in an embodiment of the present application;

[0022] Figure 4 is a dimensional diagram of the millimeter wave radar antenna provided in an embodiment of the present application;

[0023] Figure 5 yes Figure 4 AA section view;

[0024] Figure 6 is a longitudinal cross-sectional view of a millimeter-wave radar antenna provided in an embodiment of the present application;

[0025] Figure 7 is a transverse cross-sectional view of a millimeter wave radar antenna provided in an embodiment of the present application;

[0026] Figure 8 is a reflection coefficient S11 curve diagram provided in an embodiment of the present application;

[0027] Fig. 9 This is the antenna pattern provided in the embodiment of the present application.

[0028] Description of the figure number:

[0029] Substrate 10, laminated structure 11, metal cavity 12, slot array 13, feeding port 14, dielectric plate 111, metal plate 112, isolation cavity 113, slot 131;

[0030] Substrate 10: a first surface 101 and a second surface 102;

[0031] Metal cavity 12: top A, bottom B, side wall C;

[0032] The stacked structure 11 includes a first layer structure L1, a second layer structure L2, a third layer structure L3, a fourth layer structure L4, a fifth layer structure L5, a sixth layer structure L6, and a seventh layer structure L7. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

[0035] In order to solve the problems of high cost of high-frequency plates in existing millimeter-wave radar antennas and excessive size of radar equipment, the present application provides a millimeter-wave radar antenna and radar equipment. By adopting a laminated structure and a metal cavity design, the compactness and high integration of the antenna system can be achieved, thereby effectively reducing the manufacturing cost and reducing the overall volume. In other words, through this design, the millimeter-wave radar antenna can be made more stable and efficient in performance, and the production cost can be reduced and the size of the equipment can be reduced. The design of the metal cavity and the slot array helps to improve the radiation characteristics and frequency response of the antenna. This means that by designing the metal cavity and the slot array, the performance of the antenna can be optimized so that it can better adapt to the working environment under the millimeter-wave frequency band and improve the performance of the radar equipment in this frequency band.

[0036] Combine the following Figure 1-Figure 9 The millimeter wave radar antenna and radar device of the present application are described.

[0037] Please refer to Figure 1 to Figure 7 , Figure 1 is a stereogram of a millimeter wave radar antenna provided in an embodiment of the present application, Figure 2 yes Figure 1 A partial enlarged view of the laminated structure. Figure 3 is a bottom view of the millimeter wave radar antenna provided in an embodiment of the present application, Figure 4 is a dimension diagram of the millimeter wave radar antenna provided in an embodiment of the present application, Figure 5 yes Figure 4 AA cross-section diagram, Figure 6 is a longitudinal cross-sectional view of a millimeter wave radar antenna provided in an embodiment of the present application, Figure 7 1 is a transverse cross-sectional view of a millimeter wave radar antenna provided in an embodiment of the present application. A millimeter wave radar antenna includes a substrate 10 and a metal cavity 12.

[0038] Exemplarily, the substrate 10 includes a multilayer dielectric plate 111 and a multilayer metal plate 112, which are alternately stacked to form a stacked structure 11. The substrate 10 has a first surface 101 and a second surface 102 opposite thereto. The first surface 101 is provided with a slot array 13, and the second surface 102 is provided with a feeding port 14. The side wall of each slot 131 in the slot array 13 is covered with a layer of metal material.

[0039] Exemplarily, the top A and bottom B of the metal cavity 12 are formed by the metal plates 112 of the corresponding layers of the stacked structure 11, the side wall C of the metal cavity 12 is covered with a layer of metal material, and the slot array 13 and the feeding port 14 are connected in the metal cavity 12 so that the slot array 13 transmits the signal output by the feeding port 14 and receives the signal scattered back by the target.

[0040] The millimeter-wave radar antenna described in this application is a waveguide embedded PCB (Printed Circuit Board) antenna design. Specifically, by performing relevant processing on the PCB stack, combined with copper plating technology, the gap 131 and the side wall of the metal cavity 12 are covered with metal materials, thereby realizing the waveguide working mode. In addition, a slot array structure is designed. Compared with the traditional patch antenna, the millimeter-wave antenna of this application does not need to use high-frequency plates, thereby saving costs. At the same time, compared with the traditional waveguide antenna, the present application reduces the volume in the vertical direction, so that the radar can be more miniaturized.

[0041] For example, Figure 2 As shown, the substrate 10 includes a multi-layer dielectric plate 111 and a multi-layer metal plate 112 , and the multi-layer dielectric plate 111 and the multi-layer metal plate 112 are alternately stacked.

[0042] like Figure 5 As shown, Figure 5 It is shown that the substrate 10 includes seven layers, namely L1 to L7. The substrate 10 is a laminated structure 11, and the number of laminates can be appropriately reduced or increased according to actual needs during the antenna design process. Therefore, the present application is not limited to the use of 7-layer boards, and the number of layers of the substrate 10 can be appropriately adjusted according to the specific antenna design requirements to achieve the best antenna performance. In other words, in different application scenarios, the substrate 10 can be adjusted to adapt to different working environments and requirements, thereby improving the applicability and reliability of the antenna.

[0043] Specifically, the substrate 10 adopts a laminated structure technology, and the first layer structure L1 in the laminated structure 11 is composed of a layer of dielectric plate, and the other layers of structures (i.e., L2-L7) are composed of a layer of metal plate 112 and a layer of dielectric plate 111. For example, the first layer structure L1 is composed of a first dielectric plate, and the second layer structure L2 is composed of a first metal plate and a second dielectric plate. The laminated structure 11 can effectively reduce the interference and loss of electromagnetic waves and improve the stability of radar operation. In addition, in the manufacturing process of the millimeter wave radar antenna, a glass fiber reinforced epoxy resin substrate (Flame Retardant4, referred to as FR4) plate is used as a dielectric material, which can save the cost of high-frequency plates, thereby saving manufacturing costs. Compared with conventional patch antennas, the laminated structure 11 described in the present application can also reduce the difficulty and complexity of manufacturing.

[0044] Specifically, the first layer structure L1 can support and fix the metal layer, and it also plays an important role in controlling the polarization direction of electrical properties in antenna design. The first dielectric plate of the first layer structure L1 is located at the top of the substrate 10. The stacked structure 11 is sequentially composed of the first layer structure L1, the second layer structure L2, the third layer structure L3, the fourth layer structure L4, the fifth layer structure L5, the sixth layer structure L6 and the seventh layer structure L7 along the direction away from the first surface 101. Among them, the first layer structure L1 includes a first dielectric plate. The second layer structure L2 includes a first metal plate and a second dielectric plate, and each slot 131 of the slot array 13 penetrates the first dielectric plate of the first layer structure L1 and the first metal plate of the second layer structure L2.

[0045] Exemplarily, the metal plate 112 of the second layer structure L2 to the seventh layer structure L7 has a gap at one end close to the side wall C of the metal cavity 12 to form an isolation cavity 113. The setting of the isolation cavity 113 can make the metal plate 112 of the substrate 10 have no electrical connection with the side wall C of the metal cavity 12.

[0046] In the actual product development process, the metal plates 112 of each layer may be grounded, while the metal cavity 12 is not grounded, and the setting of the isolation cavity 113 can make the metal plates 112 have no electrical connection with the side walls of the metal cavity 12. In other words, the function of the isolation cavity 113 is to isolate the metal plates 112 of the second layer structure L2 to the seventh layer structure L7 from the side walls of the metal cavity 12 to prevent them from being electrically connected. Therefore, the function of the isolation cavity 113 is to effectively isolate the electrical connection between the metal plates 112 of the second layer to the seventh layer structure and the side walls of the metal cavity 12, thereby preventing electromagnetic interference.

[0047] For example, Figure 6 , Figure 7 As shown, a rectangular slot can be opened on the dielectric plate 111 of the seventh layer structure L7 to introduce the feeding port 14 to feed the slot antenna. The size of the rectangular slot can be selected according to the antenna frequency band and can be appropriately adjusted according to the specific design.

[0048] When the feeding port 14 transmits a signal, the signal is transmitted from the slot array 13 through the metal cavity 12. Since the metal cavity 12 is not grounded, the setting of the isolation cavity 113 makes the metal plate 112 not electrically connected to the side wall of the metal cavity 12. Through this design, the radiation and transmission path of the signal can be effectively controlled, the interference with other signals can be reduced, and the radiation efficiency and directivity of the signal can be improved.

[0049] It should be noted that, on the substrate 10, the metal plate 112 of the second layer structure L2 and the seventh layer structure L7 can be used to establish the top A and bottom B of the metal cavity 12 in the horizontal direction, and the side wall C is formed in the vertical direction and covered with a metal coating. The metal cavity 12 formed in this way can realize a waveguide-like working mode.

[0050] In this design, the horizontal metal plate 112 and the vertical metal coating are combined to form a metal cavity 12. The metal cavity 12 can guide and transmit electromagnetic wave signals like a waveguide, limit the propagation range of electromagnetic waves, and reduce the impact of external interference on the signal. By constructing the metal cavity 12, the transmission path and radiation characteristics of the signal can be effectively controlled, and the performance and stability of the antenna can be improved.

[0051] like Figure 4 As shown, the metal cavity 12 is a rectangular cavity, and the length of the metal cavity 12 is L g , width W g , length L g The width W can be adjusted according to the number of gaps 131. g It can be designed according to the antenna frequency band.

[0052] In millimeter wave antenna systems, since the antenna operating frequency band is often higher, the antenna structure requires more stringent design and manufacturing standards. As an important component of the antenna system, the size and shape of the metal cavity 12 need to match the selected operating frequency band and other parameters to achieve the best antenna performance. The rectangular cavity design can meet the frequency requirements within a certain range, and the length L g and width W g The adjustment can meet the requirements of different frequency bands and antenna models to improve the bandwidth, gain, directivity or other performance indicators of the antenna. Therefore, in the design process of the antenna system, sufficient analysis and simulation are required to ensure that the size and shape of the metal cavity 12 meet the required performance indicators and meet the technical requirements and working conditions of the entire system.

[0053] like Figure 4 As shown, the thickness of the metal material covering the inner wall of each gap 131 can be 30-40 microns. The length of each gap 131 is L sl , width W sl The length L of each gap 131 is sl Approximately equal to λ g / 2, the spacing L between two adjacent gaps 131 is approximately equal to λ g / 2, where λ g Represents the wavelength propagating in the waveguide.

[0054] Specifically, Where λ is the wavelength of electromagnetic waves propagating in free space.

[0055] For example, the shortest distance from the center point of each of the first and last gaps 131 to the side wall of the metal cavity 12 along the length direction of the metal cavity 12 is λ g / Integer multiple of 4.

[0056] For example, Figure 4 As shown, the shortest distance L from the center point of the leftmost gap 131 to the side wall of the metal cavity 12 is s is g / 4, the shortest distance L from the center point of the rightmost gap 131 to the side wall of the metal cavity 12 p is g / Integer multiple of 4.

[0057] When setting the slot 131, a specific side lobe level distribution can be achieved by adjusting the position of the slot 131. Specifically, the vertical distance from each slot 131 to the center line K of the metal cavity 12 is different. According to the Chebyshev distribution, the vertical distance d from the slot 131 in the middle of the metal cavity 12 to the center line K is the largest, and gradually decreases toward both ends.

[0058] Chebyshev distribution is a commonly used technique in signal processing and filter design, which achieves a specific frequency response by controlling the amplitude distribution of the signal. Here, according to the characteristics of Chebyshev distribution, the gap 131 is set so that the vertical distance from the center line K of the metal cavity 12 is adjusted as the position changes, thereby achieving a suitable distribution of the side lobe level in the waveguide.

[0059] By precisely adjusting the position and distance of the slot 131, the propagation and radiation characteristics of the waves in the waveguide can be affected, which helps to optimize the performance of the antenna system, such as reducing sidelobe radiation, improving antenna directivity, etc., to meet different operating frequency bands and performance requirements.

[0060] In summary, the millimeter-wave radar antenna proposed in this application is to embed the antenna directly into a printed circuit board (ie, substrate), thereby realizing the function of a traditional patch antenna while reducing the cost of high-frequency panels. In addition, compared with traditional waveguide antennas, the volume is reduced in the vertical direction, so that the radar equipment can be more miniaturized. The core idea of ​​this application is to integrate the antenna directly into the printed circuit board instead of using traditional patch antennas or waveguide antennas. In this way, performance similar to that of traditional patch antennas can be achieved at a lower cost. At the same time, since the large volume of the waveguide limits the size of equipment such as radar, a more miniaturized radar system can be achieved by reducing the volume of the antenna in the vertical direction.

[0061] Please refer to Figure 8 , Figure 8 It is a reflection coefficient S11 curve graph provided in an embodiment of the present application. Figure 8 The reflection coefficient S11 curve of the millimeter wave antenna described in the present application in the working frequency band of 76.9 GHz-80.9 GHz is shown. The S11 curve is a curve used to evaluate the antenna echo performance, which refers to the relationship between the reflection coefficient of the antenna input port and the incident wave.

[0062] For the millimeter wave antenna of the present application, its operating frequency band is within the range of 76.9 GHz-80.9 GHz, which means that the antenna design can be used to receive and send signals with a frequency between 76.9 GHz and 80.9 GHz. When performing antenna simulation, by calculating the reflection coefficient S11 curve of the antenna and analyzing this curve, the echo characteristics of the antenna can be evaluated to determine whether the matching state of the antenna is good.

[0063] Please refer to Fig. 9 , Fig. 9 This is the antenna pattern provided in the embodiment of the present application. Fig. 9 The performance of the millimeter wave antenna described in this application at a frequency of 79.5GHz is shown, and the antenna pattern at this frequency is obtained through antenna simulation calculation. Among them, the maximum gain is 14.6dBi, which means that the output power of the antenna in a certain direction is the highest gain value in all directions under the same input power. The 3dB beam width in the azimuth plane is 102.1°, which means the beam width corresponding to when the gain in the radiation direction of the antenna is reduced to half of the maximum gain value, and the coverage range in the horizontal plane (azimuth plane) is relatively wide.

[0064] The maximum beam pointing direction of the elevation plane is 0°, which means that the main radiation direction of the antenna in the vertical direction is zero angle. The 3dB beam width of the elevation plane is 11.7°, which means the coverage range of the antenna in the vertical direction, that is, when the angle in the elevation direction is ±5.85°, its gain is reduced to half of the maximum gain value.

[0065] The sidelobe level of 22.3dB means that the signal strength outside the radiation range is lower than that in the main radiation direction by 22.3dB. Generally speaking, the smaller the sidelobe level, the better the antenna's directivity and anti-interference ability.

[0066] In some embodiments of the present application, the present application further provides a radar device, wherein the radar device includes the millimeter wave radar antenna as described in any of the above embodiments.

[0067] The application of the millimeter-wave radar antenna in radar equipment can achieve high-precision target recognition, tracking and monitoring, and has broad application prospects in the fields of autonomous driving vehicles, security monitoring, meteorological observation, and drone navigation.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A millimeter wave radar antenna, characterized in that: The millimeter wave radar antenna comprises: A substrate, comprising a multi-layer dielectric plate and a multi-layer metal plate, wherein the multi-layer dielectric plate and the multi-layer metal plate are alternately stacked to form a laminated structure, wherein the substrate has a first surface and a second surface opposite thereto, wherein the first surface is provided with a slot array, and the second surface is provided with a feeding port, and the side wall of each slot in the slot array is covered with a layer of metal material; A metal cavity, the top and bottom of the metal cavity are formed by metal plates of corresponding layers of the laminated structure, the side walls of the metal cavity are covered with a layer of metal material, and the slot array and the feeding port are connected in the metal cavity so that the slot array transmits the signal output by the feeding port and receives the signal scattered back by the target.

2. The millimeter wave radar antenna according to claim 1, characterized in that: The stacked structure includes, in a direction away from the first surface, a first layer structure consisting of a first dielectric plate and a second layer structure consisting of a first metal plate and a second dielectric plate, and each slot in the slot array penetrates the first dielectric plate and the first metal plate.

3. The millimeter wave radar antenna according to claim 2, characterized in that: The millimeter wave radar antenna also includes a plurality of isolation cavities, each of which is located at one end of each metal plate close to the side wall of the metal cavity so that the metal plate is not electrically connected to the side wall of the metal cavity.

4. The millimeter wave radar antenna according to claim 1, characterized in that: The metal cavity is a rectangular cavity, and the wavelength propagated in the waveguide is Where λ represents the wavelength of electromagnetic waves propagating in free space, W g Represents the wide side of the metal cavity.

5. The millimeter wave radar antenna according to claim 1, characterized in that: The length of each slit and the distance between two adjacent slits are approximately equal to λ g / 2.

6. The millimeter wave radar antenna according to claim 1, characterized in that: The shortest distance from the center point of each of the first and last gaps to the side wall of the metal cavity along the length direction of the metal cavity is λ g / Integer multiple of 4.

7. The millimeter wave radar antenna according to claim 1, characterized in that: The metal cavity is not grounded.

8. The millimeter wave radar antenna according to claim 2, characterized in that: The medium plate is a glass fiber reinforced epoxy resin substrate plate.

9. The millimeter wave radar antenna according to claim 1, characterized in that: The vertical distance between the gap in the middle of the metal cavity and the center line of the metal cavity is the largest and gradually decreases toward both ends.

10. A radar device, characterized in that: The radar device comprises the millimeter wave radar antenna according to any one of claims 1 to 9.

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