Single-layer waveguide antenna structure

Abstract

The present invention relates to a single-layer waveguide antenna structure. In this structure, it is composed of a spliced PCB main board and a waveguide board, and a column-mushroom pin composite structure is arranged therein. Among them, the mushroom pins are arranged in the PCB main board, and the columns are arranged in the waveguide board. The PCB main board is also provided with a transmission waveguide wall, a radiation waveguide wall, and a grounding layer; the waveguide board is also provided with a transmission waveguide cavity and a radiation cavity; the transmission waveguide wall, the mushroom pins, the transmission waveguide cavity, and the columns form a closed waveguide cavity, and the transmission waveguide wall serves as the bottom H-plane of the waveguide cavity, thereby realizing the single-layer waveguide antenna structure. By adopting the single-layer waveguide antenna structure of the present invention, bottleneck problems such as high-frequency signal reflection loss and adjacent channel coupling crosstalk caused by the heterogeneous material interface and assembly tolerance sensitivity between the traditional waveguide system and the PCB are overcome, the number of columns in the waveguide board can be effectively reduced, and it is beneficial to simplify the manufacturing difficulty of the waveguide board.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter-wave radar, in particular to the technical field of waveguide antennas, and specifically refers to a single-layer waveguide antenna structure. Background Art

[0002] In order to adapt to the complexity of the environment and roads, vehicle-mounted millimeter-wave radars need to have a sufficiently large aperture and a sufficient number of channels to achieve ultra-high resolution for precise perception of pedestrians and surrounding obstacles. Therefore, the performance of millimeter-wave radars needs to be further improved.

[0003] Currently, the LOP packaging technology (Launch On Package) has become mature, and direct signal transmission between MMIC (Monolithic Microwave Integrated Circuits) and waveguide antennas is achieved through waveguides inside the PCB. Compared with the current board-level microstrip antennas designed on printed circuit boards (PCBs), waveguide antennas can further reduce feeder losses, improve channel consistency, and enhance the performance of millimeter-wave radar modules.

[0004] Since the routing method of waveguide antennas is an internal cavity, it usually needs to be divided into several parts for processing and then assembled and installed later. The current mainstream low-cost solution is to splice double-layer waveguide plates and then combine them with the PCB. As Figure 1 shown, the multi-layer waveguide plate structure is complex, and processing and the splicing process between layers mean an increase in radar cost.

[0005] How to implement a single-layer waveguide antenna in an easy-to-process manner and solve the electrical connection problem between the waveguide plate and the PCB is the difficulty of the design. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art and provide a single-layer waveguide antenna structure.

[0007] To achieve the above purpose, the single-layer waveguide antenna structure of the present invention is as follows:

[0008] The single-layer waveguide antenna structure is mainly characterized in that it is composed of a splicing of a PCB main board and a waveguide plate, and a post-mushroom pin composite structure is provided therein. Among them, the mushroom pin is arranged in the PCB main board, the post is arranged in the waveguide plate, and a transmission waveguide wall, a radiation waveguide wall, and a grounding layer are also arranged in the PCB main board; a transmission waveguide cavity and a radiation cavity are also arranged in the waveguide plate; the transmission waveguide wall, the mushroom pin, the transmission waveguide cavity, and the post form a closed waveguide cavity, and the transmission waveguide wall serves as the bottom H-plane of the waveguide cavity, thereby realizing the single-layer waveguide antenna structure.

[0009] Preferably, the mushroom pins are distributed below the column, and periodically surround the edge of the radiation waveguide wall, and the coverage range of the mushroom pins is greater than or equal to the projection coverage range of the column on the PCB main board.

[0010] Preferably, at least one row of columns is disposed around the side wall at one end of the transmission waveguide cavity, the distance between adjacent columns along the signal transmission direction is not greater than one-quarter wavelength, and the sizes and shapes of the columns are the same / different.

[0011] Preferably, the mushroom pin includes a metal patch and a metal through hole. Among them, the upper end of the metal through hole is connected to the metal patch, the lower end is connected to the ground layer, the axis of the metal through hole is located at the geometric center of the metal patch, and the transmission waveguide wall and the metal patch are both printed on the upper surface of the PCB main board.

[0012] Preferably, the mushroom pins are equally spaced around both ends of the transmission waveguide wall, and the metal patch is connected or partially overlapped with the transmission waveguide wall. At one end of the transmission waveguide wall, at least two rows of the mushroom pins are disposed around, and the coverage range of the transmission waveguide wall is greater than or equal to the projection coverage range of the transmission waveguide cavity on the PCB main board.

[0013] Preferably, the metal patch is connected or partially overlapped with the radiation waveguide wall. At one end of the radiation waveguide wall, at least two rows of mushroom pins are disposed around, and the radiation cavity, the column, the radiation waveguide wall and the mushroom pins form a complete radiator.

[0014] Preferably, the radiation cavity is symmetric about the center line BB`, and includes a waveguide cavity, a waveguide port, a first boss, a second boss, radiation slits, transition slits and choke grooves. Among them, the first boss and the second boss are located in the waveguide cavity, and the two are between adjacent radiation slits. The radiation slits are alternately distributed at both ends of the center line AA`; the transmission waveguide cavity is connected to the waveguide port and feeds the electromagnetic wave signal into the radiation cavity from the center; the transition slit is in a horn shape and is used to connect the radiation slit and the choke groove.

[0015] Preferably, columns are disposed below both the first boss and the second boss, and at least one row of columns is distributed around the side wall at one end of the waveguide cavity. The distance between adjacent columns along the signal transmission direction is not greater than one-quarter wavelength, and the sizes and shapes of the columns are the same / different.

[0016] Preferably, the coverage range of the radiation waveguide wall is greater than or equal to the projection coverage range of the waveguide cavity on the PCB main board.

[0017] Preferably, the PCB main board and the waveguide board are fixed by screwing.

[0018] With the single-layer waveguide antenna structure of the present invention, by designing an original column-mushroom pin composite structure, bottleneck problems such as high-frequency signal reflection loss and adjacent channel coupling crosstalk caused by the heterogeneous material interface and assembly tolerance sensitivity between the traditional waveguide system and the PCB are overcome, a single-layer structure of the waveguide antenna is realized, the reliability is improved, the production and manufacturing process is simplified, and the production cost is reduced. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of a double-layer waveguide antenna in the prior art.

[0020] Figure 2 It is a three-dimensional perspective view of the single-layer waveguide antenna structure of the present invention.

[0021] Figure 3 It is a partial three-dimensional perspective view of the single-layer waveguide antenna structure of the present invention.

[0022] Figure 4 It is a schematic cross-sectional view of the single-layer waveguide antenna structure of the present invention.

[0023] Figure 5 It is a three-dimensional perspective view of the radiator of the single-layer waveguide antenna structure of the present invention.

[0024] Figure 6 It is a combined top view and side view of the radiator of the single-layer waveguide antenna structure of the present invention.

[0025] Figure 7 It is a sectional view of the radiator of the single-layer waveguide antenna structure of the present invention.

[0026] Figure 8 It is a schematic diagram of the S11 simulation result of the single-layer waveguide antenna structure of the present invention in Embodiment 1.

[0027] Figure 9 It is the pattern simulation result of the single-layer waveguide antenna structure of the present invention in Embodiment 1.

[0028] Figure 10 It is a schematic structural diagram of the single-layer waveguide antenna structure of the present invention in Embodiment 2.

[0029] Figure 11 It is a schematic diagram of the transmission coefficient simulation result of the single-layer waveguide antenna structure of the present invention in Embodiment 2.

[0030] Figure 12 It is a schematic structural diagram of the single-layer waveguide antenna structure of the present invention in Embodiment 3.

[0031] Figure 13 This is a schematic diagram of the simulation result of the transmission coefficient of the single-layer waveguide antenna structure of the present invention in Embodiment 3.

[0032] Reference numerals

[0033] 1: PCB main board; 11: Transmission waveguide wall; 12: Radiation waveguide wall; 13: Mushroom pin; 131: Metal patch;

[0034] 132: Metal through-hole; 14: Ground layer: 2: Waveguide plate; 21: Transmission waveguide cavity; 22: Radiation cavity;

[0035] 221: Waveguide cavity; 222: Waveguide port; 223: First boss; 224: Second boss; 225: Radiation slot;

[0036] 226: Transition slot; 227: Choke groove; 23: Column Detailed implementation manners

[0037] In order to be able to more clearly describe the technical content of the present invention, the following will be further described in conjunction with specific embodiments.

[0038] Before detailing the embodiments according to the present invention, it should be noted that, hereinafter, the terms "comprising", "including" or any other variant are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0039] Please refer to Figure 2 As shown, the single-layer waveguide antenna structure is composed of a spliced PCB main board 1 and waveguide plate 2. The PCB main board 1 is provided with a transmission waveguide wall 11, a radiation waveguide wall 12, a mushroom pin 13 and a ground layer 14. The waveguide plate 2 is provided with a transmission waveguide cavity 21, a radiation cavity 22 and a column 23.

[0040] The transmission waveguide wall 11 serves as the bottom H-plane of the waveguide cavity. The transmission waveguide wall 11, the mushroom pin 13, the transmission waveguide cavity 21 and the column 23 form a closed waveguide cavity, realizing a single-layer structure of the transmission line waveguide.

[0041] The mushroom pin 13 is composed of a metal patch 131 and a metal through-hole 132. The metal through-hole 132 connects the metal patch 131 to the ground layer 14. The transmission waveguide wall 11 and the metal patch 131 are printed on the upper surface of the PCB main board 1.

[0042] The upright columns 23 are distributed along the side walls of the transmission waveguide cavity 21, and the distribution density along the signal transmission direction is greater than 40%. The distance between adjacent upright columns 23 along the signal transmission direction is not greater than one-quarter wavelength, and the sizes and shapes of the upright columns 23 do not have to be uniform. At one end of the transmission waveguide cavity 21, at least one row of upright columns 23 is surrounded. The coverage range of the transmission waveguide wall 11 is greater than or equal to the projection coverage range of the transmission waveguide cavity 21 on the PCB main board 1. The mushroom pins 13 are evenly surrounded at both ends of the transmission waveguide wall 11. The metal patches 131 are connected to or partially overlap with the transmission waveguide wall 11. At one end of the transmission waveguide wall 11, at least two rows of mushroom pins 13 are surrounded.

[0043] The mushroom pins 13 are distributed below the upright columns 23, and the coverage range of the mushroom pins 13 is greater than or equal to the projection coverage range of the upright columns 23 on the PCB main board 1.

[0044] The radiation cavity 22 is composed of a waveguide cavity 221, a waveguide port 222, a first boss 223, a second boss 224, a radiation slot 225, a transition slot 226, and a choke groove 227.

[0045] The transmission waveguide cavity 21 is connected to the waveguide port 222, and the electromagnetic wave signal is fed into the radiation cavity 22 from the center. Central feeding can increase the pattern bandwidth, and the maximum pointing direction of the pattern gain will not shift due to frequency changes.

[0046] The structure of the radiation cavity 22 is symmetric about the center line BB`. The radiation slots 225 are alternately distributed at both ends of the center line AA`. The number of radiation slots 225 can be changed according to design requirements. If it is necessary to increase the gain, the number of radiation slots 225 is increased.

[0047] The first boss 223 and the second boss 224 are located inside the waveguide cavity 221 and between adjacent radiation slots 225. Controlling the sizes of the first boss 223 and the second boss 224 can play a role in adjusting impedance matching.

[0048] The transition slot 226 is in a horn shape and connects the radiation slot 225 and the choke groove 227; the choke groove 227 can improve the cross-polarization isolation and increase the gain.

[0049] By jointly adjusting the width of the radiation slot 225 and the angle of the horn-shaped opening of the transition slot 226, the radiation intensity of each slot can be controlled, and the main lobe and side lobes of the radiation pattern can be adjusted.

[0050] A column 23 is provided below the first boss 223 and the second boss 224. The column 23 is distributed along the side wall of the waveguide cavity 221, and the distribution density along the signal transmission direction is greater than 40%. The distance between adjacent columns 23 along the signal transmission direction is not greater than one-quarter wavelength. The size and shape of the column 23 do not have to be uniform. At one end of the waveguide cavity 221, at least one row of columns 23 is surrounded. The coverage range of the radiation waveguide wall 12 is greater than or equal to the projection coverage range of the waveguide cavity 221 on the PCB main board 1; the mushroom pins 13 are periodically surrounded by the edge of the radiation waveguide wall 12, and the metal patch 131 is connected or partially overlapped with the radiation waveguide wall 12. At one end of the radiation waveguide wall 12, at least two rows of mushroom pins 13 are surrounded. The radiation cavity 22, the column 23, the radiation waveguide wall 12, and the mushroom pin 13 form a complete radiator.

[0051] The column 23 and the mushroom pin 13 are used in combination to form a column-mushroom pin composite structure. One of the structures in the column-mushroom pin composite structure can be used only in a local area as needed, which can reduce the use of the column 23.

[0052] Next, the single-layer waveguide antenna structure of the present invention will be further described in conjunction with specific embodiments: Embodiment 1

[0053] As Figure 2 shown, it is composed of the splicing of the PCB main board 1 and the waveguide board 2. The material of the PCB main board 1 is low-cost FR4, and the material of the waveguide board 2 can be a metal material or a plastic part with surface metallization. The PCB main board 1 is composed of a transmission waveguide wall 11, a radiation waveguide wall 12, mushroom pins 13, and a ground layer 14. The waveguide board 2 is provided with a transmission waveguide cavity 21, a radiation cavity 22, and a column 23.

[0054] As Figure 3 is a partial three-dimensional view of the combination of the PCB main board 1 and the waveguide board 2 with respect to the waveguide transmission cavity. The transmission waveguide wall 11 serves as the bottom H plane of the waveguide cavity. The transmission waveguide wall 11, the mushroom pins 13, the transmission waveguide cavity 21, and the column 23 form a closed waveguide cavity, realizing a single-layer structure of the transmission line waveguide. The transmission line waveguide in this embodiment is a ridge waveguide. The mushroom pin 13 is composed of a metal patch 131 and a metal through hole 132. The shape of the metal patch 131 is a square, and it can also be a circle or other regular polygons. The axis of the metal through hole 132 is located at the geometric center of the metal patch 131, and the metal through hole 132 connects the metal patch 131 and the ground layer 14. The transmission waveguide wall 11 and the metal patch 131 are printed on the upper surface of the PCB main board 1.

[0055] As Figure 4is the cross-section of the transmission waveguide cavity. The columns 23 are distributed along the side wall of the transmission waveguide cavity 21, and the distribution density along the signal transmission direction is greater than 40%. The spacing between adjacent columns 23 along the signal transmission direction is not greater than one-quarter wavelength, and the sizes and shapes of the columns 23 do not have to be uniform. At one end of the transmission waveguide cavity 21, two rows of columns 23 are surrounded. The coverage range of the transmission waveguide wall 11 is greater than the projection coverage range of the transmission waveguide cavity 21 on the PCB main board 1. The mushroom pins 13 are evenly distributed along both ends of the transmission waveguide wall 11. The metal patches 131 are connected to the transmission waveguide wall 11. At one end of the transmission waveguide wall 11, three rows of mushroom pins 13 are surrounded. The mushroom pins 13 are distributed below the columns 23, and the coverage range of the mushroom pins 13 is greater than the projection coverage range of the columns 23 on the PCB main board 1.

[0056] As Figures 5 to 7 shown, the radiation cavity 22 is composed of a waveguide cavity 221, a waveguide port 222, a first boss 223, a second boss 224, a radiation slot 225, a transition slot 226, and a choke groove 227. The transmission waveguide cavity 21 is connected to the waveguide port 222 to feed the electromagnetic wave signal into the radiation cavity 22 from the center. Central feeding can increase the pattern bandwidth, and the maximum pointing of the pattern gain will not shift due to frequency changes. The structure of the radiation cavity 22 is symmetric about the center line BB`. The radiation slots 225 are alternately distributed at both ends of the center line AA`, and the center spacing between adjacent radiation slots 225 is about one-half waveguide wavelength.

[0057] In this embodiment, there are a total of 4 radiation slots 225; the first boss 223 and the second boss 224 are located inside the waveguide cavity 221, between adjacent radiation slots 225. Controlling the sizes of the first boss 223 and the second boss 224 can play a role in adjusting impedance matching. The transition slot 226 opens upward in a horn shape, connecting the radiation slot 225 and the choke groove 227; the shape of the choke groove 227 is square, and the choke groove 227 can improve the cross-polarization isolation and increase the gain. By jointly adjusting the width of the radiation slot 225 and the angle of the horn-shaped opening of the transition slot 226, the radiation intensity of each slot can be controlled, and the main lobe and side lobes of the radiation pattern can be adjusted. Columns 23 are provided below the first boss 223 and the second boss 224. The columns 23 are distributed along the side wall of the waveguide cavity 221, and the distribution density along the signal transmission direction is greater than 40%. The distance between adjacent columns 23 along the signal transmission direction is not greater than one-quarter wavelength, and the sizes and shapes of the columns 23 do not have to be unified. At one end of the waveguide cavity 221, two rows of columns 23 are surrounded. The coverage range of the radiation waveguide wall 12 is greater than the projection coverage range of the waveguide cavity 221 on the PCB main board 1; the mushroom pins 13 are periodically surrounded along the edge of the radiation waveguide wall 12, and the metal patches 131 are connected to or partially overlap with the radiation waveguide wall 12. At one end of the radiation waveguide wall 12, three rows of mushroom pins 13 are surrounded. The radiation cavity 22, the columns 23, the radiation waveguide wall 12, and the mushroom pins 13 form a complete radiator.

[0058] The PCB main board 1 and the waveguide board 2 are fixed together by screwing. The composite structure of the columns - mushroom pins can improve the assembly tolerance ability between the PCB main board 1 and the waveguide board 2.

[0059] As Figure 8 shown is the S11 simulation result of this embodiment. It can be seen from it that the frequency band range with S11 < -14 dB covers 76 - 80 GHz. The radiation pattern is as Figure 9 shown, the antenna gain reaches 16 dB, and the side lobe level reaches -20 dB. Embodiment Two

[0060] As Figure 10 is a single-layer waveguide transmission line structure, composed of a PCB main board 1 and a waveguide board 2. Among them, a transmission waveguide wall 11, mushroom pins 13, and a ground layer 14 are provided on the PCB main board 1, and a transmission waveguide cavity 21 and columns 23 are provided in the waveguide board 2.

[0061] The length of the transmission waveguide cavity 21 is 20 mm. At both ends of half of the transmission waveguide cavity 21, no columns 23 are provided, that is, the columns 23 and the mushroom pins 13 are not used in combination in this area. As Figure 11As shown, its transmission loss S21 > -0.1 dB, and the unit transmission loss is less than 0.05 dB / cm, still having excellent transmission performance. The combined use of the column-mushroom pin composite structure can reduce the number of columns 23 in the waveguide plate 2, which is beneficial to simplifying the manufacturing difficulty of the waveguide plate.

[0062] In a further embodiment, the column-mushroom pin composite structure can be used in combination with waveguide conversion structures, transmission line structures, power divider structures, and radiation structures in single-layer waveguide antennas. Embodiment Three

[0063] Due to the limitations of the part forming process, the minimum features and spacing of the columns 23 can hardly be less than 0.7 mm. In actual applications, when the spacing between adjacent channels is too small or other narrow spaces result in only one row of columns 23 being able to be formed, if there is an assembly error between the waveguide plate and the PCB, the isolation between adjacent channels will deteriorate, crosstalk will occur, and the performance of the radar module will be reduced. With the existing bandgap formation technology, it is difficult to avoid the above problems. As Figure 13 shown, using the column-mushroom pin composite structure provided by this technical solution, a multi-row mushroom pin structure can be formed in a limited space, and the isolation can be improved from -20 dB to -40 dB.

[0064] In the existing bandgap technology, units such as cylinders and rectangular bodies are arranged periodically. By adopting the column-mushroom pin composite structure of this technical solution, the periodic distribution rule of the traditional structural units is broken. This structural design is a new type of bandgap structure, which is an improvement on the existing bandgap technology and has relatively prominent innovation.

[0065] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "embodiment" etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0066] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

[0067] Adopting the single-layer waveguide antenna structure of the present invention, by designing an original column-mushroom pin composite structure, the bottleneck problems such as high-frequency signal reflection loss and adjacent channel coupling crosstalk caused by the heterogeneous material interface and assembly tolerance sensitivity between the traditional waveguide system and the PCB are overcome, a single-layer structure of waveguide transmission and antenna is realized, the reliability is improved, the production and manufacturing difficulty and cost are reduced, and it is more conducive to mass production.

[0068] In this specification, the present invention has been described with reference to its specific embodiments. However, it is obvious that various modifications and transformations can still be made without departing from the spirit and scope of the present invention. Therefore, the specification and the drawings should be regarded as illustrative rather than restrictive.

Claims

1. A single-layer waveguide antenna structure, characterized in that, It is composed of a spliced PCB main board (1) and a waveguide board (2), and a column-mushroom pin composite structure is arranged therein. Among them, the mushroom pin (13) is arranged in the PCB main board (1), and the mushroom pin (13) includes a metal patch (131) and a metal through hole (132); the column (23) is arranged in the waveguide board (2), and the mushroom pins (13) are distributed below the column (23); a transmission waveguide wall (11), a radiation waveguide wall (12) and a ground layer (14) are also arranged in the PCB main board (1); a transmission waveguide cavity (21) and a radiation cavity (22) are also arranged in the waveguide board (2); the transmission waveguide wall (11), the mushroom pin (13), the transmission waveguide cavity (21), and the column (23) form a closed waveguide cavity, and the transmission waveguide wall (11) serves as the bottom H-plane of the waveguide cavity, thereby realizing a single-layer waveguide antenna structure.

2. The single-layer waveguide antenna structure according to claim 1, characterized in that, The mushroom pins (13) are periodically surrounded around the edge of the radiation waveguide wall (12), and the coverage range of the mushroom pins (13) is greater than or equal to the projection coverage range of the column (23) on the PCB main board (1).

3. The single-layer waveguide antenna structure according to claim 1, characterized in that, On the side wall at one end of the transmission waveguide cavity (21), at least one row of columns (23) is arranged in a surrounding manner, and the spacing between adjacent columns (23) in the signal transmission direction is not greater than one-quarter wavelength, and the sizes and shapes of the columns (23) are the same / different.

4. The single-layer waveguide antenna structure according to claim 1, characterized in that, The upper end of the metal through hole (132) is connected to the metal patch (131), and the lower end is connected to the ground layer (14). The axis of the metal through hole (132) is located at the geometric center of the metal patch (131), and both the transmission waveguide wall (11) and the metal patch (131) are printed on the upper surface of the PCB main board (1).

5. The single-layer waveguide antenna structure according to claim 4, characterized in that, The mushroom pins (13) are equally spaced around both ends of the transmission waveguide wall (11), and the metal patch (131) is connected or partially overlapped with the transmission waveguide wall (11). At one end of the transmission waveguide wall (11), at least two rows of the mushroom pins (13) are arranged in a surrounding manner, and the coverage range of the transmission waveguide wall (11) is greater than or equal to the projection coverage range of the transmission waveguide cavity (21) on the PCB main board (1).

6. The single-layer waveguide antenna structure according to claim 4, wherein The metal patch (131) is connected or partially overlapped with the radiation waveguide wall (12). At one end of the radiation waveguide wall (12), at least two rows of mushroom pins (13) are arranged in a surrounding manner, and the radiation cavity (22), the column (23), the radiation waveguide wall (12) and the mushroom pins (13) form a complete radiator.

7. The single-layer waveguide antenna structure according to claim 1, characterized in that The described radiation cavity (22) is symmetric about the center line BB`, and includes a waveguide cavity (221), a waveguide port (222), a first boss (223), a second boss (224), a radiation slot (225), a transition slot (226), and a choke groove (227). Among them, the first boss (223) and the second boss (224) are located inside the waveguide cavity (221), and the two are between adjacent radiation slots (225). The radiation slots (225) are alternately distributed at both ends of the center line AA`. The transmission waveguide cavity (21) is connected to the waveguide port (222) and feeds the electromagnetic wave signal into the radiation cavity (22) from the center. The transition slot (226) is in a horn shape and is used to connect the radiation slot (225) and the choke groove (227).

8. The single-layer waveguide antenna structure according to claim 7, wherein, Posts (23) are provided below both the first boss (223) and the second boss (224). At least one row of the posts (23) is distributed around the side wall at one end of the waveguide cavity (221). The distance between adjacent posts (23) in the signal transmission direction is not greater than one-quarter wavelength, and the sizes and shapes of the posts (23) are the same / different.

9. The single-layer waveguide antenna structure according to claim 7, characterized in that The coverage range of the radiation waveguide wall (12) is greater than or equal to the projection coverage range of the waveguide cavity (221) on the PCB main board (1).

10. The single-layer waveguide antenna structure according to claim 1, wherein, The PCB main board (1) and the waveguide board (2) are fixed by screwing.

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