Millimeter wave waveguide antenna

Abstract

The utility model discloses a millimeter wave waveguide antenna, comprising a first metal layer; the second metal layer is arranged on one side of the first metal layer and attached to the first metal layer, and the antenna is characterized in that a waveguide transmission groove and beam width limiting grooves formed in the two sides of the waveguide transmission groove are formed in the side, facing the first metal layer, of the second metal layer; a plurality of radiation slots are formed in the positions, corresponding to the waveguide transmission grooves, of the first metal layer, and limiting slots corresponding to the beam width limiting grooves are formed in the positions, located on the two sides of the radiation slots, of the first metal layer; a waveguide blocking groove is further arranged between the second metal layer and the first metal layer, the wave beam width limiting groove and the waveguide transmission groove are surrounded by the waveguide blocking groove, and the waveguide blocking groove and the first metal layer form a waveguide blocking cavity used for preventing electromagnetic waves from leaking from a gap between the first metal layer and the second metal layer. According to the utility model, the problem that the existing waveguide antenna which is assembled in a layered manner and has a simple structure is poor in gap tolerance can be solved.

Description

Technical Field

[0001] This utility model relates to the field of millimeter-wave radar technology, specifically to a millimeter-wave waveguide antenna. Background Technology

[0002] With the rapid development of ADAS technology, as its functions and performance become increasingly powerful, the performance requirements for the sensors used are also becoming higher. As a very important sensor in ADAS systems, millimeter-wave radar inevitably faces new and higher performance requirements. Microstrip lines are widely used in millimeter-wave radar due to their advantages such as low cost and simple processing. However, microstrip lines have high loss and narrow bandwidth. Replacing the original microstrip antenna with a waveguide antenna with low loss and high bandwidth has naturally become an important direction for the performance breakthrough of 77GHz millimeter-wave radar. Existing waveguide antennas are either simple in structure but have poor tolerance for gaps caused by production and assembly processes, and even a slight gap will cause serious degradation of antenna performance. Or, although they can tolerate gaps caused by production and assembly, their structures are relatively complex, which is not conducive to production and mass production. Therefore, there is an urgent need for a waveguide antenna with a simple structure that can still maintain stable performance even when there are certain gaps in the assembly process. Utility Model Content

[0003] This invention provides a millimeter-wave waveguide antenna that can solve the problem of poor gap tolerance in current layered, simple waveguide antennas.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a millimeter-wave waveguide antenna, comprising: a first metal layer; and a second metal layer disposed on one side of the first metal layer and attached to the first metal layer, characterized in that a waveguide transmission groove and a beamwidth limiting groove disposed on both sides of the waveguide transmission groove are provided on the side of the second metal layer facing the first metal layer, a plurality of radiation slots are provided on the first metal layer at positions corresponding to the waveguide transmission grooves, and limiting slots corresponding to the beamwidth limiting grooves are provided on both sides of the radiation slots on the first metal layer, the beamwidth limiting grooves and the limiting slots forming a beamwidth limiting cavity for adjusting the beamwidth of the waveguide antenna in the horizontal direction;

[0005] A waveguide blocking groove is also provided between the second metal layer and the first metal layer. The waveguide blocking groove surrounds the beamwidth limiting groove and the waveguide transmission groove. The waveguide blocking groove and the first metal layer form a waveguide blocking cavity to prevent electromagnetic waves from leaking from the gap between the first metal layer and the second metal layer. The beamwidth of the waveguide antenna in the horizontal direction can be adjusted by setting the position of the beamwidth limiting cavity, and it is relatively flexible.

[0006] By setting several radiating slots, the resonant frequency of the waveguide antenna can be adjusted to the required operating frequency band. By reasonably adjusting the distance between the radiating slots and the longitudinal centerline of the waveguide transmission groove, the sidelobes of the waveguide antenna pattern can meet the preset conditions.

[0007] By incorporating waveguide blocking cavities, waveguide antennas can tolerate installation gaps to a certain extent, facilitating production and assembly, thereby ensuring the stability and consistency of antenna performance.

[0008] Preferably, the radiating slots are rectangular through slots, and the radiating slots are arranged in an alternating pattern along the longitudinal centerline of the waveguide transmission slot. By reasonably adjusting the spacing between the radiating slots, the beam of the waveguide antenna elevation pattern is made to point in a preset direction.

[0009] Preferably, the radiating slot is set parallel to or at an angle to the longitudinal centerline of the waveguide transmission groove. By adjusting the direction of the radiating slot, the resonant frequency of the waveguide antenna can be made to be in the required operating frequency band.

[0010] Preferably, the length of the beamwidth limiting slot is less than the length of the waveguide transmission slot.

[0011] Preferably, the beamwidth limiting slot on the left and the waveguide transmission slot share the first left side wall of the waveguide transmission slot, and the beamwidth limiting slot on the right and the waveguide transmission slot share the first right side wall of the waveguide transmission slot. The first left side wall and the first right side wall have the same width. The beamwidth limiting slot on the left and the waveguide blocking slot on the left share the second left side wall of the beamwidth limiting slot, and the beamwidth limiting slot on the right and the waveguide blocking slot on the right share the second right side wall of the beamwidth limiting slot. The second left side wall and the second right side wall have the same width. This structure is compact, facilitates the processing of the waveguide transmission slot, the beamwidth limiting slot, and the waveguide blocking slot, and ensures that the spacing between the waveguide transmission slot and the beamwidth limiting slots and waveguide blocking slots on both sides is equal.

[0012] Preferably, the waveguide blocking slot includes two longitudinal blocking slots located outside the beamwidth limiting slot and a transverse blocking slot located outside the end of the waveguide transmission slot. The longitudinal and transverse blocking slots can surround the beamwidth limiting slot and the waveguide transmission slot, preventing electromagnetic waves from leaking from the gap between the first metal layer and the second metal layer, thereby ensuring the stable performance of the waveguide antenna.

[0013] Preferably, the end of the beamwidth limiting groove is connected to the transverse blocking groove, which can reduce the processing difficulty and facilitate integral molding.

[0014] Preferably, the mating surfaces of the first and second metal layers are both smooth metal surfaces, which can reduce the loss during electromagnetic wave transmission.

[0015] Preferably, a rectangular ridge is provided in the middle of the bottom of the waveguide transmission groove, which can meet the needs of different forms of high-frequency signal transmission.

[0016] Preferably, the cross-sections of the waveguide transmission groove, the beamwidth limiting groove, and the waveguide blocking groove are rectangular, which is beneficial for the transmission of electromagnetic waves.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] The horizontal beamwidth of the waveguide antenna can be adjusted flexibly by setting the position of the beamwidth limiting cavity. The resonant frequency of the waveguide antenna can be adjusted to the desired operating frequency band by setting several radiation slots. By reasonably adjusting the distance between the radiation slots and the longitudinal centerline of the waveguide transmission slot, the sidelobes of the waveguide antenna pattern can meet preset conditions. The waveguide blocking cavity provides tolerance to installation gaps, facilitating production and assembly, thus ensuring the stability and consistency of antenna performance. The structure is simple, with few components and no separately processed parts, greatly reducing mold complexity and production difficulty, thereby lowering production costs. Attached Figure Description

[0019] Figure 1 A schematic diagram of a millimeter-wave antenna structure according to an embodiment of the present invention is shown.

[0020] Figure 2 A cross-sectional view of a millimeter-wave waveguide antenna according to an embodiment of the present invention is shown.

[0021] Figure 3 This diagram shows a top view of the first metal layer of a millimeter-wave waveguide antenna according to an embodiment of the present invention.

[0022] Figure 4 A cross-sectional view of the second metal layer of a millimeter-wave waveguide antenna according to an embodiment of the present invention is shown.

[0023] Figure 5 This diagram shows a perspective view of the second metal layer of a millimeter-wave waveguide antenna according to an embodiment of the present invention.

[0024] Figure 6 This diagram shows a top view of the second metal layer of a millimeter-wave waveguide antenna according to an embodiment of the present invention.

[0025] Figure 7 The S-parameter curves of the millimeter-wave waveguide antenna according to an embodiment of the present invention are shown.

[0026] Figure 8 The radiation pattern of the millimeter-wave waveguide antenna according to an embodiment of the present invention is shown.

[0027] Figure label:

[0028] 1. First metal layer; 11. Radiation slit; 12. Limiting slit; 2. Second metal layer; 21. Waveguide transmission groove; 211. Rectangular ridge; 213. First left side wall; 214. First right side wall; 22. Beamwidth limiting groove; 221. Beamwidth limiting cavity; 222. Second left side wall; 223. Second right side wall; 23. Waveguide blocking groove; 231. Waveguide blocking cavity; 232. Longitudinal blocking groove; 233. Transverse blocking groove. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0030] This invention addresses the problem of poor gap tolerance in current layered, simple waveguide antennas. For example... Figure 1-8 As shown, the following technical solution is provided: a millimeter-wave waveguide antenna, comprising: a first metal layer 1; a second metal layer 2, disposed on one side of the first metal layer 1 and attached to the first metal layer 1, wherein the second metal layer 2 has a waveguide transmission groove 21 and beamwidth limiting grooves 22 disposed on both sides of the waveguide transmission groove 21 facing the first metal layer 1, wherein the first metal layer 1 has a plurality of radiation slots 11 at positions corresponding to the waveguide transmission grooves 21, and wherein the first metal layer 1 has limiting slots 12 on both sides of the radiation slots 11 corresponding to the beamwidth limiting grooves 22, wherein the beamwidth limiting grooves 22 and the limiting slots 12 constitute a beamwidth limiting cavity 221 for adjusting the beamwidth of the waveguide antenna in the horizontal direction;

[0031] A waveguide blocking groove 23 is also provided between the second metal layer 2 and the first metal layer 1. The waveguide blocking groove 23 surrounds the beamwidth limiting groove 22 and the waveguide transmission groove 21. The waveguide blocking groove 23 and the first metal layer 1 form a waveguide blocking cavity 231 for preventing electromagnetic waves from leaking from the gap between the first metal layer 1 and the second metal layer 2. The beamwidth of the waveguide antenna in the horizontal direction can be adjusted by setting the position of the beamwidth limiting cavity 221, which is relatively flexible.

[0032] By setting several radiation slots 11, the resonant frequency of the waveguide antenna can be adjusted to the required operating frequency band. By reasonably adjusting the distance of the radiation slots 11 from the longitudinal centerline of the waveguide transmission groove 21, the sidelobes of the waveguide antenna pattern can meet the preset conditions.

[0033] By setting the waveguide blocking cavity 231, the waveguide antenna has a certain tolerance for installation gaps, which facilitates production and assembly, thereby ensuring the stability and consistency of antenna performance.

[0034] Specifically, the first metal layer 1 and the second metal layer 2 are processed separately, either by stamping from metal sheets. However, since the upper side of the second metal layer 2 requires multiple grooves, it can be machined using CNC machining. Alternatively, the second metal layer 2 can be made by laminating a metal layer onto the surface of a plastic base layer. The choice can be made according to needs, as long as the mating surfaces of the first metal layer 1 and the second metal layer 2 are smooth metal surfaces to reduce electromagnetic wave transmission loss. The gap between the first metal layer 1 and the second metal layer 2 should be as small as possible.

[0035] In this embodiment, after the electromagnetic wave is transmitted to the waveguide transmission slot 21, it is radiated out through the radiation slot 11, thus functioning as a waveguide antenna. For example, Figure 1 and 3 As shown, the radiating slots 11 are rectangular through slots. The dimensions of each radiating slot 11 can be the same or different. The radiating slots 11 are arranged in a staggered pattern along the longitudinal centerline of the waveguide transmission slot 21. By reasonably adjusting the spacing between the radiating slots 11, the beam of the waveguide antenna's elevation pattern can be directed in a preset direction. The cross-sections of the waveguide transmission slot 21, the beamwidth limiting slot 22, and the waveguide blocking slot 23 are rectangular, which is beneficial for the transmission of electromagnetic waves.

[0036] like Figure 7 As shown, Figure 7 The S-parameter curve of the waveguide antenna designed according to this embodiment is shown. The antenna operates in the frequency band of 75.4GHz to 82.3GHz and has a bandwidth of 6.9GHz@-10dB. It can be clearly seen from the figure that the bandwidth of the S-parameter curve is relatively wide after adopting the technical solution in this embodiment.

[0037] like Figure 8 The image shows the radiation pattern of the waveguide antenna. Figure 8 There are four curves. The first curve at the top represents a waveguide antenna with a working frequency of 77GHz, phi = 0deg, and a gap of 0mm between the first metal layer 1 and the second metal layer 2. The second curve below it represents a waveguide antenna with a working frequency of 77GHz, phi = 0deg, and a gap of 0.2mm.

[0038] Located in Figure 8 The third curve at the bottom represents a waveguide antenna with an operating frequency of 77GHz, phi = 90deg, and a gap of 0mm between the first metal layer 1 and the second metal layer 2. The fourth curve on one side of the third curve represents a waveguide antenna with an operating frequency of 77GHz, phi = 90deg, and a gap of 0.2mm between the first metal layer 1 and the second metal layer 2.

[0039] from Figure 8As can be seen, the waveguide antennas of the second and fourth curves have a gap of 0.2mm, but the first and third curves with a gap of 0 in their radiation patterns have roughly the same shape, indicating that when there is a 0.2mm gap between the first metal layer 1 and the second metal layer 2, the radiation pattern of the waveguide antenna is minimally affected.

[0040] In this embodiment, the radiating slot 11 is parallel to or at an angle to the longitudinal centerline of the waveguide transmission groove 21. By adjusting the direction of the radiating slot 11, the resonant frequency of the waveguide antenna can be made to be in the required operating frequency band. For example, if the radiating slot 11 and the longitudinal centerline of the waveguide transmission groove 21 are at an angle of 5-10°, the direction and resonant frequency of the electromagnetic waves emitted from the radiating slot 11 can be adjusted.

[0041] In this embodiment, the waveguide transmission slot 21 is usually connected to the waveguide feed line of the waveguide antenna. The waveguide feed line will be routed according to actual needs. Therefore, the length of the waveguide transmission slot 21 is generally longer than the total length of the radiation slot 11. However, the length of the beamwidth limiting slot 22 has no requirements for the routing. Its length is less than the length of the waveguide transmission slot 21, which can reduce the structural size and reduce the manufacturing difficulty.

[0042] To facilitate the processing of the second metal layer 2, such as Figure 4 As shown, the beamwidth limiting slot 22 on the left and the waveguide transmission slot 21 share the first left side wall 213 of the waveguide transmission slot 21, and the beamwidth limiting slot 22 on the right and the waveguide transmission slot 21 share the first right side wall 214 of the waveguide transmission slot 21. The first left side wall 213 and the first right side wall 214 have the same width. The beamwidth limiting slot 22 on the left and the waveguide blocking slot 23 on the left share the second left side wall 222 of the beamwidth limiting slot 22, and the beamwidth limiting slot 22 on the right and the waveguide blocking slot 23 on the right share the second right side wall 223 of the beamwidth limiting slot 22. The second left side wall 222 and the second right side wall 223 have the same width. The structure is compact, which facilitates the processing of the waveguide transmission slot 21, the beamwidth limiting slot 22 and the waveguide blocking slot 23, and ensures that the spacing between the waveguide transmission slot 21 and the beamwidth limiting slots 22 and the waveguide blocking slots 23 on the left and right sides is equal.

[0043] The beamwidth limiting slot 22 and the waveguide transmission slot 21 have the same width, are aligned at the ends, and have the same or different lengths, which are used to adjust the beamwidth of the waveguide antenna in the horizontal direction.

[0044] like Figure 5As shown, the waveguide blocking groove 23 includes two longitudinal blocking grooves 232 located outside the beamwidth limiting groove 22 and a transverse blocking groove 233 located outside the end of the waveguide transmission groove 21. The longitudinal blocking grooves 232 and the transverse blocking groove 233 surround the beamwidth limiting groove 22 and the waveguide transmission groove 21, preventing electromagnetic waves from leaking from the gap between the first metal layer 1 and the second metal layer 2, thereby ensuring the stable performance of the waveguide antenna. The end of the beamwidth limiting groove 22 is connected to the transverse blocking groove 233, which reduces processing difficulty and facilitates integral molding. The width and depth of the longitudinal blocking groove 232 and the transverse blocking groove 233 are consistent.

[0045] In this embodiment, as Figure 4-6 As shown, a rectangular ridge 211 is provided in the middle of the bottom of the waveguide transmission groove 21, which can meet the needs of different forms of high-frequency signal transmission.

[0046] Therefore, by adopting the technical solution in this embodiment, not only is the structure of the waveguide antenna reduced, but the horizontal beamwidth of the waveguide antenna can also be adjusted by setting the position of the beamwidth limiting cavity, which is more flexible. By setting several radiation slots, the resonant frequency of the waveguide antenna can be adjusted to the required operating frequency band. By reasonably adjusting the distance of the radiation slots from the longitudinal centerline of the waveguide transmission slot, the sidelobes of the waveguide antenna pattern can meet the preset conditions. By setting the waveguide blocking cavity, the waveguide antenna has a certain tolerance for installation gaps, which is convenient for production and assembly, thereby ensuring the stability and consistency of antenna performance.

[0047] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0048] Furthermore, in this utility model, descriptions involving terms such as "primary," "secondary," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "primary" or "secondary" may explicitly or implicitly include at least one of those features. In the description of this utility model, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly and specifically defined.

[0049] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0050] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

Claims

1. A millimeter-wave waveguide antenna, characterized in that, include: First metal layer (1); The second metal layer (2) is disposed on one side of the first metal layer (1) and is attached to the first metal layer (1). The second metal layer (2) is characterized by having a waveguide transmission groove (21) and a beamwidth limiting groove (22) disposed on both sides of the waveguide transmission groove (21) on the side facing the first metal layer (1). The first metal layer (1) is provided with a plurality of radiation slots (11) at positions corresponding to the waveguide transmission groove (21). The first metal layer (1) is provided with limiting slots (12) corresponding to the beamwidth limiting grooves (22) on both sides of the radiation slots (11). The beamwidth limiting grooves (22) and the limiting slots (12) together form a beamwidth limiting cavity (221) for adjusting the beamwidth of the waveguide antenna in the horizontal direction. A waveguide blocking groove (23) is also provided between the second metal layer (2) and the first metal layer (1). The waveguide blocking groove (23) surrounds the beamwidth limiting groove (22) and the waveguide transmission groove (21). The waveguide blocking groove (23) and the first metal layer (1) form a waveguide blocking cavity (231) for preventing electromagnetic waves from leaking from the gap between the first metal layer (1) and the second metal layer (2).

2. The millimeter-wave waveguide antenna according to claim 1, characterized in that: The radiation slot (11) is a rectangular through slot, and the radiation slots (11) are arranged in an alternating pattern along the longitudinal centerline of the waveguide transmission slot (21).

3. The millimeter-wave waveguide antenna according to claim 2, characterized in that: The radiation slit (11) is parallel to or at an angle to the longitudinal centerline of the waveguide transmission groove (21).

4. The millimeter-wave waveguide antenna according to claim 1, characterized in that: The length of the beamwidth limiting slot (22) is less than the length of the waveguide transmission slot (21).

5. The millimeter-wave waveguide antenna according to claim 1, characterized in that: The beamwidth limiting slot (22) on the left and the waveguide transmission slot (21) share the first left side wall (213) of the waveguide transmission slot (21), and the beamwidth limiting slot (22) on the right and the waveguide transmission slot (21) share the first right side wall (214) of the waveguide transmission slot (21). The first left side wall (213) and the first right side wall (214) have the same width. The beamwidth limiting slot (22) on the left and the waveguide blocking slot (23) on the left share the second left side wall (222) of the beamwidth limiting slot (22), and the beamwidth limiting slot (22) on the right and the waveguide blocking slot (23) on the right share the second right side wall (223) of the beamwidth limiting slot (22). The second left side wall (222) and the second right side wall (223) have the same width.

6. The millimeter-wave waveguide antenna according to claim 1, characterized in that: The waveguide blocking groove (23) includes two longitudinal blocking grooves (232) located outside the beamwidth limiting groove (22) and a transverse blocking groove (233) located outside the end of the waveguide transmission groove (21).

7. The millimeter-wave waveguide antenna according to claim 6, characterized in that: The end of the beamwidth limiting groove (22) is connected to the transverse blocking groove (233).

8. The millimeter-wave waveguide antenna according to claim 1, characterized in that: The surfaces of the first metal layer (1) and the second metal layer (2) that are in contact with each other are smooth metal surfaces.

9. The millimeter-wave waveguide antenna according to claim 1, characterized in that: A rectangular ridge (211) is provided in the middle of the bottom of the waveguide transmission groove (21).

10. The millimeter-wave waveguide antenna according to claim 1, characterized in that: The cross-sections of the waveguide transmission groove (21), the beamwidth limiting groove (22), and the waveguide blocking groove (23) are rectangular.

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