Antenna system and vehicle-mounted millimeter-wave radar

Abstract

Embodiments of the present invention relate to the field of antenna technology and disclose an antenna system and an on-vehicle millimeter-wave radar. The system includes an antenna array and a first and second grounding layers for the antenna array. The antenna array is configured to radiate electromagnetic waves into free space. A first PCB surface, where the first grounding layer is located, is provided with a plurality of metal patches spaced apart. The metal patches are configured to adjust the phase of the reflected electromagnetic waves formed after the electromagnetic waves are reflected. Through this approach, embodiments of the present invention enhance the wide-angle sensing capabilities of the antenna system.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of antenna technology, and more particularly to an antenna system and a vehicle-mounted millimeter-wave radar. Background Art

[0002] With the continuous development of intelligent driving technology, automotive millimeter-wave radar has been widely used. Automotive millimeter-wave radar is a detection radar operating in the millimeter-wave band, detecting obstacles around the vehicle through an antenna system.

[0003] In related art, millimeter-wave radar antenna systems typically consist of an antenna array and a metal ground plane. The antenna array radiates high-frequency radar signals into free space. However, during the implementation of the present invention, the inventors discovered that the high-frequency radar signals radiated by the antenna array generate reflected radar signals after passing through the metal ground plane. These reflected radar signals cancel each other out, resulting in dimples in the antenna array's radiation pattern at wide angles and poor wide-angle sensing capabilities. Summary of the Invention

[0004] In view of the above problems, embodiments of the present invention provide an antenna system and a vehicle-mounted millimeter-wave radar, which are used to solve the problem of poor large-angle perception capability of the antenna system in the prior art.

[0005] According to one aspect of an embodiment of the present invention, an antenna system is provided, comprising an antenna array and a first ground layer and a second ground layer of the antenna array, wherein the antenna array is configured to radiate electromagnetic waves into free space, and a plurality of metal patches are spaced apart on a first PCB surface where the first ground layer is located, wherein the metal patches are configured to adjust the phase of a reflected electromagnetic wave formed after the electromagnetic wave is reflected.

[0006] In an optional manner, the metal patch is square, and the side length of the metal patch is one quarter of the waveguide wavelength.

[0007] In an optional manner, the lateral spacing and the longitudinal spacing between adjacent metal patches are both half the waveguide wavelength.

[0008] In an optional manner, the antenna array is located on the second PCB surface, the second ground layer is located on the third PCB surface, a first dielectric layer is arranged between the first PCB surface and the second PCB surface, and a second dielectric layer is arranged between the first PCB surface and the third PCB surface.

[0009] In an optional manner, the first ground layer is located directly below the antenna array, and the metal patches are distributed on the left and right sides of the first ground layer.

[0010] In an optional manner, the metal patch is evenly spread over the entire area of ​​the first PCB surface except the first ground layer.

[0011] In an optional manner, the second ground layer is evenly spread over the entire third PCB surface.

[0012] In an optional manner, the metal patch is circular, and the diameter of the metal patch is one quarter of the waveguide wavelength.

[0013] In an optional manner, the width of the antenna array is smaller than the width of the first ground layer.

[0014] According to another aspect of an embodiment of the present invention, a vehicle-mounted millimeter-wave radar is provided, and the millimeter-wave radar includes the above-mentioned antenna system.

[0015] In an embodiment of the present invention, an antenna system includes an antenna array and a first and second ground layers of the antenna array. The antenna array can radiate electromagnetic waves into free space. A plurality of metal patches are spaced apart on a first PCB surface where the first ground layer resides. The metal patches are used to adjust the phase of reflected electromagnetic waves formed after the electromagnetic waves are reflected. As can be seen, by spaced apart metal patches on the first PCB surface, the phase of the reflected electromagnetic waves formed after the electromagnetic waves are reflected can be adjusted, allowing the reflected electromagnetic waves to overlap with the electromagnetic waves radiated by the antenna array at large angles. This eliminates any large-angle pits in the antenna array's radiation pattern and improves the antenna array's wide-angle sensing capability.

[0016] The above description is only an overview of the technical solutions of the embodiments of the present invention. In order to more clearly understand the technical means of the embodiments of the present invention, they can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiments of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are specifically listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present invention. In addition, the same reference symbols are used to represent the same components throughout the drawings. In the drawings:

[0018] Figure 1 A schematic structural diagram of an antenna system provided by an embodiment of the present invention is shown;

[0019] Figure 2 A schematic structural diagram of an antenna system provided by another embodiment of the present invention is shown;

[0020] Figure 3 A schematic diagram showing a directional pattern of an antenna system provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0021] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0022] Figure 1 FIG1 shows a schematic diagram of the structure of an antenna system provided by an embodiment of the present invention, which can be applied to a vehicle-mounted millimeter wave radar. Figure 1 As shown, the antenna system includes an antenna array 10 and first and second ground layers 20 and 30 of the antenna array. The first and second ground layers 20 and 30 are generally metal ground layers. The antenna array 10 is used to radiate electromagnetic waves into free space. A plurality of metal patches 60 are spaced apart on the first PCB surface where the first ground layer 20 is located. The metal patches 60 are used to adjust the phase of the reflected electromagnetic waves formed after the electromagnetic waves are reflected.

[0023] The electromagnetic waves radiated by the on-board millimeter-wave radar have a high frequency and a short wavelength. The electrical size of an antenna system is the ratio of its physical size to the wavelength of the electromagnetic wave. Given a given physical size of the antenna system's PCB, the shorter the wavelength of the electromagnetic wave, the larger the electrical size of the antenna system's PCB. After being powered on, the antenna array 10 can radiate electromagnetic waves into free space. Some of the electromagnetic waves radiated by the antenna array 10 are reflected by the second ground layer 30 to form reflected electromagnetic waves. The reflected electromagnetic waves and the electromagnetic waves radiated by the antenna array 10 cancel each other out at large angles, creating a concave pattern in the antenna array 10's radiation pattern. This reduces the gain of the on-board millimeter-wave radar at large angles and weakens its ability to detect obstacles at large angles.

[0024] By arranging a plurality of metal patches 60 at intervals on the first PCB surface where the first ground layer 20 is located, the phase of the reflected electromagnetic wave formed by the electromagnetic wave refracted by the second ground layer 30 changes after passing through the metal patch 60, so that the reflected electromagnetic wave and the electromagnetic wave radiated by the antenna array 10 no longer cancel each other out at large angles, thereby avoiding the formation of pits in the radiation pattern of the antenna array 10 at large angles, improving the large-angle gain of the on-board millimeter-wave radar, and enhancing the on-board millimeter-wave radar's ability to detect obstacles at large angles.

[0025] In an embodiment of the present invention, an antenna system includes an antenna array and a first and second ground layers of the antenna array. The antenna array can radiate electromagnetic waves into free space. A plurality of metal patches are spaced apart on a first PCB surface where the first ground layer resides. The metal patches are used to adjust the phase of reflected electromagnetic waves formed after the electromagnetic waves are reflected. As can be seen, by spaced apart metal patches on the first PCB surface, the phase of the reflected electromagnetic waves formed after the electromagnetic waves are reflected can be adjusted, allowing the reflected electromagnetic waves to overlap with the electromagnetic waves radiated by the antenna array at large angles. This eliminates any large-angle pits in the antenna array's radiation pattern and improves the antenna array's wide-angle sensing capability.

[0026] In the PCB of the antenna system, the antenna array 10 is located on the second PCB surface, and the second ground layer 30 is located on the third PCB surface. A first dielectric layer 40 is disposed between the first and second PCB surfaces, and a second dielectric layer 50 is disposed between the first and third PCB surfaces. In an embodiment of the present invention, the second PCB surface is located on the upper surface of the first dielectric layer 40, the first PCB surface is located on the lower surface of the first dielectric layer 40, and the third PCB surface is located on the lower surface of the second dielectric layer 50. The first and second dielectric layers 40, 50 can support the antenna array 10, the metal patch 60, the first and second ground layers 20, 30. Furthermore, the metal patch 60 can have a square or circular shape. The antenna array 10 can be located in the middle of the second PCB surface, and the first ground layer 20 can be located in the middle of the first PCB surface. The width of the antenna array 10 is smaller than the width of the first ground layer 20.

[0027] Figure 2 FIG. 1 shows a schematic structural diagram of an antenna system provided by another embodiment of the present invention. Figure 2 As shown, the metal patch 60 is square. The side length of the metal patch 60 can be designed according to actual needs, and can be, for example, a quarter of the waveguide wavelength. Furthermore, the lateral and longitudinal spacing between adjacent metal patches 60 can also be designed according to actual needs. For example, the lateral and longitudinal spacing between adjacent metal patches 60 can both be designed to be half the waveguide wavelength.

[0028] The first ground layer 20 can be located directly below the antenna array 10, and the metal patches 60 can be distributed on both sides of the first ground layer 20. Furthermore, the metal patches 60 can be evenly spread across the entire area of ​​the first PCB surface except for the first ground layer. Furthermore, the second ground layer 30 can be evenly spread across the entire third PCB surface.

[0029] In another embodiment, the combined shape of the metal patches 60 can be circular, and the diameter of the metal patches 60 is a quarter of the waveguide wavelength. The lateral spacing and the longitudinal spacing between adjacent metal patches 60 are both designed to be half the waveguide wavelength, for example.

[0030] Figure 3 FIG. 1 shows a schematic diagram of the directional pattern of the antenna system provided by an embodiment of the present invention. Figure 3 As shown, the dashed line represents the directional pattern of a conventional antenna system, while the solid line represents the directional pattern of the antenna system of the present invention. It can be seen that the directional pattern of the conventional antenna system has multiple pits at high angles, resulting in low gain at high angles and weak obstacle detection capabilities at high angles. The antenna system of the present invention avoids these pits at high angles, resulting in high gain at high angles and strong obstacle detection capabilities at high angles.

[0031] In an embodiment of the present invention, an antenna system includes an antenna array and a first and second ground layers of the antenna array. The antenna array can radiate electromagnetic waves into free space. A plurality of metal patches are spaced apart on a first PCB surface where the first ground layer resides. The metal patches are used to adjust the phase of reflected electromagnetic waves formed after the electromagnetic waves are reflected. As can be seen, by spaced apart metal patches on the first PCB surface, the phase of the reflected electromagnetic waves formed after the electromagnetic waves are reflected can be adjusted, allowing the reflected electromagnetic waves to overlap with the electromagnetic waves radiated by the antenna array at large angles. This eliminates any large-angle pits in the antenna array's radiation pattern and improves the antenna array's wide-angle sensing capability.

[0032] In addition, an embodiment of the present invention further provides a vehicle-mounted millimeter-wave radar, which includes the above-mentioned antenna system. The antenna system of the vehicle-mounted millimeter-wave radar includes an antenna array and a first ground layer and a second ground layer of the antenna array. The antenna array can radiate electromagnetic waves into free space; a plurality of metal patches are arranged at intervals on the first PCB surface where the first ground layer is located, and the metal patches are used to adjust the phase of the reflected electromagnetic wave formed after the electromagnetic wave is reflected. It can be seen that by arranging a plurality of metal patches at intervals on the first PCB surface, the phase of the reflected electromagnetic wave formed after the electromagnetic wave is reflected can be adjusted, so that the reflected electromagnetic wave and the electromagnetic wave radiated by the antenna array are superimposed at a large angle, thereby eliminating the pits generated by the radiation pattern of the antenna array in the large-angle direction, and improving the perception ability of the vehicle-mounted millimeter-wave radar in the large-angle direction.

[0033] It should be noted that, unless otherwise specified, technical terms or scientific terms used in the embodiments of the present invention should have the common meanings understood by those skilled in the art to which the embodiments of the present invention belong.

[0034] In the description of the embodiments of the present invention, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present invention.

[0035] In addition, the technical terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly indicate the quantity of the technical features indicated. In the description of the embodiments of the present invention, the meaning of "plurality" is more than two, unless otherwise specifically defined.

[0036] In the description of the embodiments of the present invention, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0037] In the description of the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," or "below" a second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention 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 or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. An antenna system, applied to millimeter wave radar, characterized in that: The system includes an antenna array and a first ground layer and a second ground layer of the antenna array. The antenna array is configured to radiate electromagnetic waves into free space. A first PCB surface where the first ground layer is located is provided with a plurality of metal patches spaced apart. The metal patches are configured to adjust the phase of a reflected electromagnetic wave formed after the electromagnetic wave is reflected by the second ground layer, so that the reflected electromagnetic wave is superimposed on the electromagnetic wave radiated by the antenna array. The antenna array is located on the second PCB surface, the second ground layer is located on the third PCB surface, a first dielectric layer is provided between the first PCB surface and the second PCB surface, and a second dielectric layer is provided between the first PCB surface and the third PCB surface; The antenna array is located in the middle of the second PCB surface, the first ground layer is located in the middle of the first PCB surface, and the width of the antenna array is smaller than the width of the first ground layer; The first ground layer is located directly below the antenna array; The metal patches are distributed on the left and right sides of the first ground layer, or the metal patches are evenly spread over the entire area of ​​the first PCB surface except the first ground layer; The second ground layer is evenly spread over the entire surface of the third PCB.

2. The antenna system according to claim 1, wherein The metal patch is square, and the side length of the metal patch is a quarter of the waveguide wavelength.

3. The antenna system according to claim 1 or 2, characterized in that The lateral spacing and the longitudinal spacing between adjacent metal patches are both half the waveguide wavelength.

4. The antenna system according to claim 1, wherein: The metal patch is circular, and the diameter of the metal patch is a quarter of the waveguide wavelength.

5. A vehicle-mounted millimeter-wave radar, characterized in that: The millimeter wave radar includes the antenna system according to any one of claims 1 to 4.

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