A waveguide cavity antenna and radar device

Abstract

The embodiment of the present application relates to the technical field of communication, and discloses a waveguide cavity antenna and a radar device.The waveguide cavity antenna comprises a metal base body provided with a radiation surface, a main transmission cavity, an auxiliary matching cavity, a radiation hole and a feed structure arranged on the metal base body;the first end of the auxiliary matching cavity is communicated with the main transmission cavity, the second end is communicated with the radiation hole, the radiation hole penetrates to the radiation surface, and the signal fed by the feed structure is transmitted to the auxiliary matching cavity through the main transmission cavity and radiated outward through the radiation hole.Through arranging the auxiliary matching cavity between the main transmission cavity and the radiation hole to match the impedance of the signal, the embodiment of the present application can reduce the impedance mismatch during electromagnetic wave propagation and radiation, reduce the reflection loss inside the cavity during high-frequency signal transmission, and improve the signal transmission efficiency of the antenna.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a waveguide cavity antenna and radar equipment. Background Technology

[0002] A waveguide cavity antenna is an antenna that uses a metallic cavity to guide electromagnetic waves to propagate and radiate outwards. It features low transmission loss, high radiation efficiency, and a compact and reliable structure, making it widely used in communication terminals, base station equipment, and radar systems—scenarios requiring efficient signal transmission and reception. In recent years, as communication and sensing equipment has continuously evolved towards higher frequencies, higher speeds, and miniaturization, the demand for signal transmission in the millimeter-wave band has been increasing. Compared to planar structures such as microstrip antennas, waveguide cavity antennas exhibit lower loss at higher frequencies, thus their application in high-frequency signal transmission and reception is becoming increasingly widespread, gradually becoming one of the important antenna types in this field.

[0003] In the process of implementing the embodiments of this application, the inventors discovered that: currently, in the process of high-frequency signal transmission, electromagnetic waves are prone to reflection when propagating inside the cavity in traditional waveguide cavity antennas, resulting in reflection loss, which leads to low signal transmission efficiency of the antenna and makes it difficult to meet the needs of high-frequency communication equipment for efficient signal transmission. Summary of the Invention

[0004] The main technical problem solved by the embodiments of this application is to provide a waveguide cavity antenna that can reduce the reflection loss inside the cavity during high-frequency signal transmission and improve the signal transmission efficiency of the antenna.

[0005] To solve the above-mentioned technical problems, one technical solution adopted in this application embodiment is: providing a waveguide cavity antenna, including a metal substrate, a radiating surface, a main transmission cavity disposed in the metal substrate, an auxiliary matching cavity disposed in the metal substrate, the auxiliary matching cavity having a first end and a second end opposite to each other, the first end of the auxiliary matching cavity communicating with the main transmission cavity, a radiating aperture, one end of the radiating aperture communicating with the second end of the auxiliary matching cavity, the other end of the radiating aperture penetrating to the radiating surface, and a feeding structure disposed in the metal substrate, wherein the signal fed into the feeding structure is transmitted through the main transmission cavity to the auxiliary matching cavity and radiated outward through the radiating aperture.

[0006] Optionally, there are multiple auxiliary matching cavities, which are spaced apart and located on the side of the main transmission cavity facing the radiation surface. The first end of each auxiliary matching cavity is connected to the main transmission cavity. There are multiple radiation holes, which correspond one-to-one with the multiple auxiliary matching cavities. One end of each radiation hole is connected to the second end of the corresponding auxiliary matching cavity, and the other end extends through to the radiation surface.

[0007] Optionally, along the signal transmission direction from the feed structure to the radiation aperture, the cross-sectional dimensions of the auxiliary matching cavity vary in stages, forming a stepped cavity structure.

[0008] Optionally, a waveguide channel is provided in the metal substrate. The waveguide channel is curved and extended. One end of the waveguide channel is connected to the feeding structure, and the other end of the waveguide channel is connected to the main transmission cavity.

[0009] Optionally, the power feeding structure includes a power feeding port, which is located on the side of the metal substrate away from the radiating surface.

[0010] Optionally, the radiating surface is provided with parallel choke grooves, which include multiple parallel grooves spaced apart from each other.

[0011] Optionally, the radiating surface is further provided with an annular choke groove, which surrounds the radiating hole.

[0012] Optionally, the main transmission cavity, the auxiliary matching cavity, and the radiation aperture constitute a radiation unit, and multiple radiation units are provided on the metal substrate.

[0013] Optionally, the plurality of radiation units include at least one transmitting unit and at least one receiving unit.

[0014] To solve the above-mentioned technical problems, another technical solution adopted in the embodiments of this application is to provide a radar device, including any of the waveguide cavity units described above.

[0015] The waveguide cavity antenna provided in this application embodiment provides an auxiliary matching cavity between the main transmission cavity and the radiation aperture. The first end of the auxiliary matching cavity is connected to the main transmission cavity, and the second end is connected to the radiation aperture. This creates an impedance transition along the signal transmission path from the main transmission cavity to the radiation aperture. The signal fed by the feeding structure passes through the main transmission cavity and the auxiliary matching cavity in sequence before being radiated outward through the radiation aperture. The auxiliary matching cavity performs impedance matching on this signal, reducing the impedance mismatch during electromagnetic wave propagation and radiation within the cavity. This reduces the reflection loss inside the cavity during high-frequency signal transmission, improves the signal transmission efficiency of the antenna, and solves the problems of high reflection loss and low signal transmission efficiency in traditional waveguide cavity antennas at high frequencies. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0017] Figure 1 This is a schematic diagram of one side of the radiating surface of the waveguide cavity antenna provided in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the back (feed side) of the waveguide cavity antenna provided in the embodiments of this application; Figure 3 This is an exploded structural diagram of the waveguide cavity antenna provided in an embodiment of this application; Figure 4 This is a schematic diagram of the main transmission cavity, auxiliary matching cavity, and stepped cavity structure in the waveguide cavity antenna provided in the embodiments of this application; Figure 5 This is a graph showing the return loss S11 of the waveguide cavity antenna provided in this application as a function of frequency. Figure 6 This is a graph showing the overall efficiency of the waveguide cavity antenna provided in this application as a function of frequency.

[0018] The reference numerals in the detailed embodiments are as follows: 100, waveguide cavity antenna; 10, metal substrate; 11, radiating surface; 111, parallel choke slot; 101, groove; 112, annular choke slot; 12, waveguide channel; 20, main transmission cavity; 30, auxiliary matching cavity; 31, stepped cavity structure; 40, radiating aperture; 50, feeding structure; 51, feeding port; 60, radiating element. Detailed Implementation

[0019] To facilitate understanding of this application, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as "connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "inner," "outer," "vertical," "horizontal," etc., used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0020] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0021] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0022] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 This application provides a waveguide cavity antenna 100, which includes a metal substrate 10. The metal substrate 10 is provided with a radiating surface 11. The metal substrate 10 is provided with a main transmission cavity 20, an auxiliary matching cavity 30 and a radiating aperture 40. The metal substrate 10 is also provided with a feeding structure 50.

[0023] Please see Figure 2 The feeding structure 50 is used to feed in signals. In some embodiments, the feeding structure 50 includes a feeding port 51, which is opened on the side of the metal substrate 10 away from the radiating surface 11, that is, on the back side of the metal substrate 10, so as to facilitate the connection of the waveguide cavity antenna 100 with the external radio frequency circuit.

[0024] Please see Figure 3 and Figure 4 The main transmission cavity 20 is disposed within the metal substrate 10 and is connected to the feeding structure 50. In some embodiments, a waveguide channel 12 is also disposed within the metal substrate 10. The waveguide channel 12 is curved and extended. One end of the waveguide channel 12 is connected to the feed port 51 of the feeding structure 50, and the other end of the waveguide channel 12 is connected to the main transmission cavity 20, thereby guiding the signal fed into the feed port 51 to the main transmission cavity 20.

[0025] The auxiliary matching cavity 30 is disposed within the metal substrate 10. The auxiliary matching cavity 30 has a first end and a second end opposite to each other. The first end of the auxiliary matching cavity 30 communicates with the main transmission cavity 20, and the second end of the auxiliary matching cavity 30 communicates with the radiation aperture 40. In some embodiments, along the signal transmission direction from the feed structure 50 to the radiation aperture 40, the cross-sectional dimensions of the auxiliary matching cavity 30 vary in stages, forming a stepped cavity structure 31. Figure 4 To form an impedance transition between the main transmission cavity 20 and the radiation aperture 40.

[0026] In some embodiments, the inner wall of at least one of the main transmission cavity 20, the auxiliary matching cavity 30, and the waveguide channel 12 is a smooth surface. For example, the inner walls of the main transmission cavity 20, the auxiliary matching cavity 30, and the waveguide channel 12 can be polished or otherwise surface-treated to reduce the surface roughness of each inner wall to less than a preset threshold. This reduces scattering and reflection of electromagnetic waves caused by unevenness of the inner walls during propagation within the cavity and channel, further reducing signal reflection loss within the cavity and improving the signal transmission efficiency of the waveguide cavity antenna 100. Furthermore, the cavity dimensions of the main transmission cavity 20 and the auxiliary matching cavity 30 can be set according to the operating frequency band of the waveguide cavity antenna 100 to match the propagation of electromagnetic waves within the cavity to the corresponding frequency band.

[0027] One end of the radiation hole 40 is connected to the second end of the auxiliary matching cavity 30, and the other end of the radiation hole 40 extends to the radiation surface 11 of the metal substrate 10.

[0028] In some embodiments, the power supply port 51 and the waveguide channel 12, and / or the waveguide channel 12 and the main transmission cavity 20 are connected in a smooth transition manner to reduce signal leakage at the connection interface and reduce signal transmission loss on the power supply path.

[0029] Therefore, the signal fed into the feed port 51 of the feed structure 50 is transmitted sequentially through the waveguide channel 12 and the main transmission cavity 20 to the auxiliary matching cavity 30. After impedance matching by the auxiliary matching cavity 30, the signal is radiated outward from the radiating surface 11 through the radiation aperture 40; the signal path is reversed during reception. By setting the auxiliary matching cavity 30 between the main transmission cavity 20 and the radiation aperture 40, the impedance mismatch during electromagnetic wave propagation and radiation within the cavity is reduced, the reflection loss inside the cavity during high-frequency signal transmission is reduced, and the signal transmission efficiency of the waveguide cavity antenna 100 is improved.

[0030] Simulation results show that the return loss S11 of the waveguide cavity antenna 100 in this embodiment is lower than that in the 62GHz to 72GHz frequency band. 10dB, please refer to Figure 5 Its overall efficiency is approximately 0.6dB to 0.8dB, please refer to Figure 6 It can meet the needs of high-frequency communication and detection equipment for efficient signal transmission.

[0031] In some embodiments, the waveguide cavity antenna 100 operates in the frequency band of 62 GHz to 72 GHz.

[0032] Please see Figure 1and Figure 4 There are multiple auxiliary matching cavities 30, which are spaced apart and are all located on the side of the main transmission cavity 20 facing the radiation surface 11. The first end of each auxiliary matching cavity 30 is connected to the same main transmission cavity 20. Correspondingly, there are multiple radiation holes 40, which correspond one-to-one with the multiple auxiliary matching cavities 30. One end of each radiation hole 40 is connected to the second end of the corresponding auxiliary matching cavity 30, and the other end extends through to the radiation surface 11.

[0033] Optionally, each of the main transmission cavities 20 is provided with four auxiliary matching cavities 30 and four radiation holes 40, combined with Figure 1 In this way, the signal in the same main transmission cavity 20 can be radiated outward simultaneously through multiple auxiliary matching cavities 30 and multiple radiation holes 40, thereby improving the aperture utilization and radiation performance at that location.

[0034] Please see Figure 1 The radiating surface 11 is further provided with choke slots. In some embodiments, the radiating surface 11 is provided with parallel choke slots 111, which include multiple parallel and spaced grooves 101. In some embodiments, the radiating surface 11 is also provided with an annular choke slot 112, which surrounds the radiating aperture 40. The parallel choke slot 111 and the annular choke slot 112 can be selectively provided on the radiating surface 11, or both can be provided on the radiating surface 11. By providing the parallel choke slot 111 and / or the annular choke slot 112 on the radiating surface 11, surface wave propagation on the radiating surface 11 can be suppressed, the coupling between adjacent radiating apertures 40 and adjacent radiating elements 60 can be reduced, and the isolation and anti-interference capability of the antenna can be improved.

[0035] Please see Figure 1 and Figure 3 The main transmission cavity 20, the auxiliary matching cavity 30 and the radiation hole 40 constitute a radiation unit 60, and a plurality of radiation units 60 are disposed on the metal substrate 10.

[0036] In some embodiments, eight radiating units 60 are disposed on the metal substrate 10. Each radiating unit 60 includes at least one transmitting unit and at least one receiving unit. For example, four of the eight radiating units 60 serve as transmitting units, and the other four serve as receiving units, forming a four-transmitter, four-receiver multi-transmitter / multi-receiver structure. The main transmission cavity 20 of each radiating unit 60 is connected to the corresponding feed port 51 via its respective waveguide channel 12. The multiple waveguide channels 12 are distributed in a curved manner within the metal substrate 10 and extend to each radiating unit 60.

[0037] The waveguide cavity antenna 100 provided in this embodiment of the application provides an auxiliary matching cavity 30 between the main transmission cavity 20 and the radiation aperture 40. The first end of the auxiliary matching cavity 30 is connected to the main transmission cavity 20, and the second end is connected to the radiation aperture 40. This creates an impedance transition along the path of the signal transmission from the main transmission cavity 20 to the radiation aperture 40. The signal fed by the feeding structure 50 passes through the main transmission cavity 20 and the auxiliary matching cavity 30 in sequence before being radiated outward through the radiation aperture 40. The auxiliary matching cavity 30 performs impedance matching on this signal, reducing the impedance mismatch during the propagation and radiation of electromagnetic waves within the cavity. This reduces the reflection loss inside the cavity during high-frequency signal transmission, improves the signal transmission efficiency of the waveguide cavity antenna 100, and solves the problems of high reflection loss and low signal transmission efficiency in traditional waveguide cavity antennas at high frequencies.

[0038] Furthermore, the waveguide cavity antenna 100 of this application embodiment, through the partitioned cavity structure in which the main transmission cavity 20 and the auxiliary matching cavity 30 cooperate, and combined with the optimization of cavity size and inner wall, not only ensures efficient signal transmission, but also helps to reduce the overall size of the antenna, adapting to the miniaturization requirements of communication equipment and detection equipment; and the waveguide cavity antenna 100 can maintain good impedance matching in a wide frequency band from 62GHz to 72GHz and has good directivity.

[0039] This application also provides a radar device (not shown), including the waveguide cavity antenna 100 described in any of the above embodiments. In some embodiments, the radar device is a vehicle-mounted radar; in other embodiments, the radar device is applied to scenarios such as obstacle avoidance by unmanned aerial vehicles (UAVs) or unmanned vehicles, transmitting and receiving radar signals through the waveguide cavity antenna 100. Because this radar device uses the aforementioned waveguide cavity antenna 100, it also has the advantages of low reflection loss and high signal transmission efficiency.

[0040] In other embodiments, the waveguide cavity antenna 100 can also be applied to communication devices, such as communication terminals and base station equipment, for transmitting and receiving high-frequency signals. Accordingly, embodiments of this application can also provide a communication device, which includes the waveguide cavity antenna 100 described in any of the above embodiments.

[0041] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A waveguide cavity antenna, characterized in that, include: A metal substrate with a radiating surface; The main transmission cavity is disposed in the metal substrate; An auxiliary matching cavity is disposed in the metal substrate. The auxiliary matching cavity has a first end and a second end that are opposite to each other. The first end of the auxiliary matching cavity is connected to the main transmission cavity. A radiation aperture, one end of which is connected to the second end of the auxiliary matching cavity, and the other end of which extends through to the radiation surface; A power feeding structure is disposed on the metal substrate. The signal fed into the power feeding structure is transmitted to the auxiliary matching cavity through the main transmission cavity and radiated outward through the radiation hole.

2. The waveguide cavity antenna according to claim 1, characterized in that, The auxiliary matching cavity is a plurality of such cavities, which are spaced apart and located on the side of the main transmission cavity facing the radiation surface. The first end of each auxiliary matching cavity is connected to the main transmission cavity. There are multiple radiation holes, and each of the multiple radiation holes corresponds one-to-one with a multiple of the auxiliary matching cavities. One end of each radiation hole is connected to the second end of the corresponding auxiliary matching cavity, and the other end extends through to the radiation surface.

3. The waveguide cavity antenna according to claim 1, characterized in that, Along the signal transmission direction from the feed structure to the radiation aperture, the cross-sectional dimensions of the auxiliary matching cavity change in stages, forming a stepped cavity structure.

4. The waveguide cavity antenna according to claim 1, characterized in that, Waveguide channels are provided within the metal matrix. The waveguide channel is curved and extended, with one end of the waveguide channel connected to the feeding structure and the other end of the waveguide channel connected to the main transmission cavity.

5. The waveguide cavity antenna according to claim 1, characterized in that, The power feeding structure includes a power feeding port, which is located on the side of the metal substrate away from the radiating surface.

6. The waveguide cavity antenna according to claim 1, characterized in that, The radiating surface is provided with parallel choke grooves, which include multiple parallel grooves spaced apart from each other.

7. The waveguide cavity antenna according to claim 1, characterized in that, The radiating surface is also provided with an annular choke groove, which surrounds the radiating hole.

8. The waveguide cavity antenna according to claim 1, characterized in that, The main transmission cavity, the auxiliary matching cavity, and the radiation aperture constitute a radiation unit, and multiple radiation units are provided on the metal substrate.

9. The waveguide cavity antenna according to claim 8, characterized in that, The plurality of radiation units include at least one transmitting unit and at least one receiving unit.

10. A radar device, characterized in that, Includes the waveguide cavity unit as described in any one of claims 1-9.

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