Circularly polarized three-frequency-band anti-interference antenna

Abstract

A circular polarization three-frequency-band anti-interference antenna belongs to the technical field of antennas, and solves the problem of complex structure of a circular polarization anti-interference antenna in the prior art, a waveguide feed layer structure of the antenna is embedded in the middle position of the bottom of a resonance layer structure, and a polarization conversion layer structure is tightly stacked on the top of the resonance layer structure; a coupling slot of the waveguide feed layer structure is communicated with a rectangular mounting groove formed in the middle position of the bottom of the resonance layer structure; a plurality of radiation slots formed in the top of the resonance layer structure are communicated with lower end openings of a plurality of polarization conversion cavities of the polarization conversion layer structure in a one-to-one correspondence manner; the feed cavity of the waveguide feed layer structure and the resonant cavity of the resonant layer structure are internally provided with a plurality of groups of intermediate-frequency anti-interference rectangular blocks and high-frequency anti-interference rectangular blocks, the antenna has low-frequency, intermediate-frequency and high-frequency anti-interference capabilities, and compared with a traditional mode of cascading a filter at the tail end of the antenna, the antenna effectively avoids cascading loss and improves the antenna performance. And the size of the system can be reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of antennas and relates to a circularly polarized three-band anti-interference antenna. Background Art

[0002] Antennas are important devices for transmitting electromagnetic signals in communication systems. Antennas are divided into two types according to their polarization mode: linear polarization and circular polarization. Linear polarization includes horizontal polarization, vertical polarization and slant polarization, while circular polarization includes left-hand circular polarization and right-hand circular polarization. Circularly polarized antennas have the advantages of multipath resistance and easy polarization matching, and are widely used in communications. In addition, with the increase in the functions of communication systems, multiple antennas are often required to send and receive electromagnetic signals, and the mutual interference between multiple antennas is relatively serious. At the same time, the electromagnetic environment in the current space is becoming increasingly complex, and the communication system is very susceptible to interference from external electromagnetic clutter.

[0003] Traditional technology usually cascades filters at the end of the antenna to solve the electromagnetic interference problem. The antenna structure and the filter structure are independent of each other. Although this form has a certain filtering effect, the cascade design of the antenna and the filter will not only increase the additional insertion loss, but also increase the volume of the system and the difficulty of design. In the prior art, integrating the filter structure into the antenna is an effective way to solve the above problem. It can not only avoid the loss caused by the cascade of the two, but also reduce the volume of the antenna system to a certain extent. However, most of the circularly polarized anti-interference antennas in the prior art have complex structures and cannot meet the application requirements of miniaturization, low profile, and low cost. Summary of the invention

[0004] The technical solution of the present invention is used to solve the problem of complex structure of circular polarization anti-interference antenna in the prior art.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] A circularly polarized three-band anti-interference antenna comprises: a waveguide feeding layer structure (10), a resonance layer structure (20), and a polarization conversion layer structure (30), wherein the waveguide feeding layer structure (10) is embedded in the middle position of the bottom of the resonance layer structure (20), and the polarization conversion layer structure (30) is tightly stacked on the top of the resonance layer structure (20); a coupling slot (103) of the waveguide feeding layer structure (10) is connected to a rectangular mounting groove (203) provided at the middle position of the bottom of the resonance layer structure (20), and a plurality of radiation slots (202) provided at the top of the resonance layer structure (20) are connected to lower end openings of a plurality of polarization conversion cavities (301) of the polarization conversion layer structure (30) in a one-to-one correspondence; and a plurality of groups of periodic intermediate frequency anti-interference rectangular blocks and high frequency anti-interference rectangular blocks are arranged inside the feeding cavity (101) of the waveguide feeding layer structure (10) and the resonance cavity (201) of the resonance layer structure (20).

[0007] Furthermore, the front end of the feeding cavity (101) of the waveguide feeding layer structure (10) is arranged as an input opening (102) protruding from the feeding cavity (101) body, the rear end of the feeding cavity (101) is closed, and four coupling slits (103) are arranged at equal intervals along the central axis of the top long side of the feeding cavity (101).

[0008] Furthermore, 8 feed layer intermediate frequency anti-interference rectangular blocks (105), 32 feed layer high frequency anti-interference rectangular blocks (106) and 4 first support base rectangular blocks (107) are arranged on the inner bottom plate of the feed cavity (101), wherein the 8 feed layer intermediate frequency anti-interference rectangular blocks (105) are evenly divided into 4 groups, and the 32 feed layer high frequency anti-interference rectangular blocks (106) are evenly divided into 4 groups. The 4 groups of feed layer intermediate frequency anti-interference rectangular blocks (105) and the 4 first support base rectangular blocks (107) are arranged at equal intervals and staggered along the long side direction of the inner bottom plate of the feed cavity (101). The 4 groups of feed layer high frequency anti-interference rectangular blocks (106) are respectively arranged on the 4 first support base rectangular blocks (107), and the height of the feed layer high frequency anti-interference rectangular blocks (106) plus the height of the first support base rectangular blocks (107) is equal to the height of the feed layer intermediate frequency anti-interference rectangular blocks (105).

[0009] Furthermore, the lower edge of the input opening (102) is flush with the top of the intermediate frequency anti-interference rectangular block (105) of the feeding layer.

[0010] Furthermore, four coupling tuning metal blocks (104) are arranged at the inner top of the feeding cavity (101), one end of the coupling tuning metal block (104) is welded to the inner top of the feeding cavity (101), and the other end of the coupling tuning metal block (104) extends downward, and the four coupling tuning metal blocks (104) are correspondingly distributed on the same side below the four coupling slits (103).

[0011] Furthermore, the top of the resonant cavity (201) of the resonant layer structure (20) is provided with 16 radiation slots (202), the 16 radiation slots (202) are evenly arranged in a 4×4 array, and a rectangular mounting groove (203) is provided in the middle of the bottom of the resonant layer structure (20), and the rectangular mounting groove (203) is used to embed the waveguide feeding layer structure (10).

[0012] Furthermore, the resonant layer structure (20) is symmetrical about the central axis of the rectangular installation groove (203) in the vertical direction, and 12 resonant layer intermediate frequency anti-interference rectangular blocks (204), 48 resonant layer high frequency anti-interference rectangular blocks (205), and 4 second support base rectangular blocks (206) are arranged on the bottom plate of the left half of the resonant layer structure (20), wherein the 12 resonant layer intermediate frequency anti-interference rectangular blocks (204) are evenly divided into 4 groups, and the 48 resonant layer high frequency anti-interference rectangular blocks (205) are evenly divided into There are four groups, the four groups of resonance layer intermediate frequency anti-interference rectangular blocks (204) and the four second support base rectangular blocks (206) are arranged in an evenly spaced and staggered manner along the long side direction of the inner bottom plate of the left half of the resonance cavity (201), the four groups of resonance layer high frequency anti-interference rectangular blocks (205) are respectively arranged on the four second support base rectangular blocks (206), and the height of the resonance layer high frequency anti-interference rectangular blocks (205) plus the height of the second support base rectangular blocks (206) is equal to the height of the resonance layer intermediate frequency anti-interference rectangular blocks (204).

[0013] Furthermore, eight radiation tuning metal blocks (207) are arranged at the inner top of the left half of the resonant cavity (201), one end of the radiation tuning metal block (207) is welded to the inner top of the resonant cavity (201), and the other end of the radiation tuning metal block (207) extends downward, and the eight radiation tuning metal blocks (207) are correspondingly staggered and distributed on both sides below the eight radiation slits (202).

[0014] Furthermore, the polarization conversion layer structure (30) comprises: 16 polarization conversion cavities (301), and the 16 polarization conversion cavities (301) are closely combined to form a 4×4 array; the polarization conversion cavity (301) comprises: a polarization conversion cavity shell (3011), and two polarization conversion plates (3012), the polarization conversion cavity shell (3011) is a rectangular metal frame with upper and lower openings, and the two polarization conversion plates (3012) are respectively vertically arranged on two inner surfaces inside the rectangular metal frame, and the two polarization conversion plates (3012) are centrally symmetrically distributed about the center of the rectangular metal frame.

[0015] Furthermore, the polarization conversion plate (3012) is a trapezoidal structure, and the hypotenuse of the trapezoidal structure adopts a stepped structure.

[0016] The advantages of the present invention are:

[0017] The waveguide feeding layer structure of the antenna of the present invention is embedded in the middle position of the bottom of the resonance layer structure, and the polarization conversion layer structure is tightly stacked on the top of the resonance layer structure; the coupling slot of the waveguide feeding layer structure is connected to the middle position of the bottom of the resonance layer structure through a rectangular installation groove, and the multiple radiation slots opened on the top of the resonance layer structure are connected to the lower end openings of the multiple polarization conversion cavities of the polarization conversion layer structure in a one-to-one correspondence; the feeding cavity of the waveguide feeding layer structure and the resonant cavity of the resonance layer structure are both provided with multiple groups of intermediate frequency anti-interference rectangular blocks and high frequency anti-interference rectangular blocks; the antenna of the present invention has low frequency, intermediate frequency and high frequency anti-interference capabilities, and compared with the traditional form of cascade filters at the end of the antenna, the antenna of the present invention effectively avoids cascade losses and can reduce the volume of the system; the antenna of the present invention adopts milling processing technology for integrated processing, which ensures processing accuracy, high reliability, wide application range and low cost; the antenna has a flat structure, which is extremely convenient when used in arrays; the antenna is made of all-metal material and has the advantages of high radiation efficiency and large power capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a front view of the overall structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0019] Figure 2 This is a front perspective view of the overall structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0020] Figure 3 It is a side perspective view of the overall structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0021] Figure 4 It is a front view of a feeding layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0022] Figure 5 It is a front perspective view of a feeding layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0023] Figure 6 It is a side perspective view of a feeding layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0024] Figure 7 is a top perspective view of a feeding layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0025] Figure 8 It is a front view of a feeding layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0026] Fig. 9It is a front perspective view of a feeding layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0027] Fig.10 It is a front perspective view of the arrangement of the coupling tuning metal blocks of the feeding layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0028] Fig.11 It is a front perspective view of the arrangement of the intermediate frequency anti-interference rectangular blocks of the feeding layer, the high frequency anti-interference rectangular blocks of the feeding layer and the rectangular blocks of the supporting base of the feeding layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention on the inner bottom plate of the feeding cavity;

[0029] Fig.12 It is a top view of the arrangement of the intermediate frequency anti-interference rectangular blocks of the feeding layer and the high frequency anti-interference rectangular blocks of the feeding layer of the feeding layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention on the inner bottom plate of the feeding cavity;

[0030] Fig.13 It is a front view of a resonant layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0031] Fig.14 It is a front perspective view of a resonant layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0032] Fig.15 is a side perspective view of a resonant layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0033] Fig.16 is a top view of a resonant layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0034] Fig.17 is a top perspective view of a resonant layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0035] Fig.18 It is a front perspective view of a resonant layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0036] Fig.19 It is a front perspective view of an anti-interference structure of a resonant layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0037] Fig. 20 is a top view of an anti-interference structure of a resonant layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0038] Fig.21It is a front view of a polarization conversion layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0039] Fig. 22 It is a top view of a polarization conversion layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0040] Fig.23 It is a front perspective view of a polarization conversion cavity shell of a polarization conversion layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0041] Fig.24 It is a front perspective view of a polarization conversion sheet of a polarization conversion cavity housing of a polarization conversion layer structure of a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention;

[0042] Fig.25 It is the main perspective view and the front perspective view of the constructed anti-interference performance simulation model;

[0043] Fig.26 It is the anti-interference performance simulation curve of the anti-interference performance simulation model built. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments:

[0046] Embodiment 1

[0047] like Figures 1 to 3 As shown, a circularly polarized three-band anti-interference antenna according to an embodiment of the present invention is a three-layer structure, which includes, from bottom to top, a waveguide feeding layer structure 10, a resonance layer structure 20, and a polarization conversion layer structure 30. The three-layer structure is a metal structure. The waveguide feeding layer structure 10 is embedded in the middle of the bottom of the resonance layer structure 20, and the polarization conversion layer structure 30 is tightly stacked on the top of the resonance layer structure 20.

[0048] like Figures 4 to 12As shown, the waveguide feeding layer structure 10 adopts a waveguide structure, and the feeding cavity 101 of the waveguide feeding layer structure 10 is a rectangular metal shell structure. The front end of the feeding cavity 101 is set as an input opening 102 protruding from the body of the feeding cavity 101, and the rear end of the feeding cavity 101 is closed. Four coupling slits 103 are evenly spaced along the central axis of the top long side of the feeding cavity 101. The coupling slits 103 are one of straight slits, elliptical slits or H-shaped slits. Figures 5 to 7 , Fig. 9 , Figure 11 to Figure 12 As shown, 8 feed layer intermediate frequency anti-interference rectangular blocks 105, 32 feed layer high frequency anti-interference rectangular blocks 106 and 4 first support base rectangular blocks 107 are arranged on the inner bottom plate of the feed cavity 101, wherein the 8 feed layer intermediate frequency anti-interference rectangular blocks 105 are evenly divided into 4 groups, and the 32 feed layer high frequency anti-interference rectangular blocks 106 are evenly divided into 4 groups. The 4 groups of feed layer intermediate frequency anti-interference rectangular blocks 105 and the 4 first support base rectangular blocks 107 are arranged at equal intervals and staggered along the long side direction of the inner bottom plate of the feed cavity 101, and the 4 groups of feed layer high frequency anti-interference rectangular blocks 106 are respectively arranged at the 4 first support base rectangular blocks 107. On a supporting base rectangular block 107, the height of the feeding layer high frequency anti-interference rectangular block 106 plus the first supporting base rectangular block 107 is equal to the height of the feeding layer intermediate frequency anti-interference rectangular block 105; according to electromagnetic field theory, the higher the frequency, the smaller the size of the corresponding electromagnetic structure, so the height of the feeding layer high frequency anti-interference rectangular block 106 is smaller than the feeding layer intermediate frequency anti-interference rectangular block 105. In order to keep the feeding layer intermediate frequency anti-interference rectangular block 105 and the feeding layer high frequency anti-interference rectangular block 106 at the same height to achieve the effect of improving electromagnetic wave transmission and shielding, the first supporting base rectangular block 107 is specially set. Figure 6 As shown, the lower edge of the input opening 102 is flush with the top of the intermediate frequency anti-interference rectangular block 105 of the feed layer. Figures 5 to 10 As shown, four coupling tuning metal blocks 104 are arranged at the inner top of the feeding cavity 101, one end of the coupling tuning metal block 104 is welded to the inner top of the feeding cavity 101, and the other end of the coupling tuning metal block 104 extends downward, and the four coupling tuning metal blocks 104 are correspondingly distributed on the same side below the four coupling slits 103.

[0049] like Figures 13 to 20 As shown, the resonant cavity 201 of the resonant layer structure 20 is a rectangular metal shell structure, 16 radiation slots 202 are opened on the top of the resonant layer structure 20, and the 16 radiation slots 202 are evenly arranged in a 4×4 array, and the radiation slots 202 are one of straight slots, elliptical slots or H-shaped slots; a rectangular mounting groove 203 is opened in the middle of the bottom of the resonant layer structure 20, and the rectangular mounting groove 203 is used to embed the waveguide feeding layer structure 10.

[0050] The resonant layer structure 20 is bilaterally symmetrical about the central axis of the rectangular mounting groove 203 in the vertical direction. The left half of the resonant layer structure 20 is taken as an example for detailed description.

[0051] The bottom plate of the left half of the resonant layer structure 20 is provided with 12 resonant layer intermediate frequency anti-interference rectangular blocks 204, 48 resonant layer high frequency anti-interference rectangular blocks 205, and 4 second support base rectangular blocks 206, wherein the 12 resonant layer intermediate frequency anti-interference rectangular blocks 204 are divided into 4 groups, and the 48 resonant layer high frequency anti-interference rectangular blocks 205 are divided into 4 groups. The 4 groups of resonant layer intermediate frequency anti-interference rectangular blocks 204 and the 4 second support base rectangular blocks 206 are arranged in an evenly spaced staggered manner along the long side direction of the inner bottom plate of the left half of the resonant cavity 201, and the 4 groups of resonant layer high frequency anti-interference rectangular blocks 205 are arranged at 4 On the second supporting base rectangular block 206, the height of the resonance layer high frequency anti-interference rectangular block 205 plus the second supporting base rectangular block 206 is equal to the height of the resonance layer intermediate frequency anti-interference rectangular block 204; according to electromagnetic field theory, the higher the frequency, the smaller the corresponding electromagnetic structure size will be, so the height of the resonance layer high frequency anti-interference rectangular block 205 is smaller than the resonance layer intermediate frequency anti-interference rectangular block 204. In order to keep the resonance layer intermediate frequency anti-interference rectangular block 204 and the resonance layer high frequency anti-interference rectangular block 205 at the same height to achieve the effect of improving electromagnetic wave transmission and shielding, the second supporting base rectangular block 206 is specially set. Figure 14 to Figure 15 , Figure 17 to Figure 18 As shown, eight radiation tuning metal blocks 207 are arranged at the inner top of the left half of the resonant cavity 201, one end of the radiation tuning metal block 207 is welded to the inner top of the resonant cavity 201, and the other end of the radiation tuning metal block 207 extends downward, and the eight radiation tuning metal blocks 207 are correspondingly staggered and distributed on both sides below the eight radiation slots 202.

[0052] like Fig.21 and Fig. 22 As shown, the polarization conversion layer structure 30 includes 16 polarization conversion cavities 301, and the 16 polarization conversion cavities 301 are closely combined to form a 4×4 array.

[0053] like Fig.23 The polarization conversion cavity 301 comprises: a polarization conversion cavity shell 3011 and two polarization conversion plates 3012. The polarization conversion cavity shell 3011 is a rectangular metal frame with upper and lower openings. The two polarization conversion plates 3012 are respectively arranged vertically on two inner surfaces inside the rectangular metal frame. The two polarization conversion plates 3012 are centrally symmetrically distributed about the center of the rectangular metal frame. The polarization conversion cavity 301 is used to convert a linear polarization signal into a circular polarization signal.

[0054] like Fig.24As shown, the polarization conversion plate 3012 is a trapezoidal structure, and the hypotenuse of the trapezoidal structure adopts a stepped structure, which is beneficial to improving the bandwidth characteristics of the antenna; by adjusting the relative positions of the two polarization conversion plates 3012, the polarization conversion cavity 301 can achieve left-hand circular polarization or right-hand circular polarization.

[0055] The working principle of the circularly polarized three-band anti-interference antenna in the embodiment of the present invention is as follows:

[0056] A rectangular mounting groove 203 is provided at the middle position of the bottom of the waveguide feeding layer structure 10 and is connected to the coupling slot 103 of the resonant layer structure 20. A coupling tuning metal block 104 is provided at a position close to the coupling slot 103 on one side below the coupling slot 103 to adjust the electromagnetic coupling characteristics. Sixteen radiation slots 202 are provided at the top of the resonant layer structure 20 and are connected to the lower end openings of the 16 polarization conversion cavities 301 of the polarization conversion layer structure 30 in a one-to-one correspondence. Radiation tuning metal blocks 207 are staggered on both sides below the radiation slots 202 to adjust the electromagnetic radiation characteristics.

[0057] When the antenna is transmitting, the electromagnetic signal is input into the feeding cavity 101 through the input opening 102 of the waveguide feeding layer structure 10, enters the resonant cavity 201 of the resonant layer structure 20 through the coupling slot 103 opened at the top of the feeding cavity 101, and then enters the polarization conversion cavity 301 of the polarization conversion layer structure 30 through the radiation slot 202 opened at the top of the resonant layer structure 20, and finally radiates into space; when the antenna is receiving, the process of the electromagnetic signal is opposite to that of the transmission.

[0058] The antenna of the present invention has low-frequency, medium-frequency and high-frequency anti-interference capabilities. This is because: on the one hand, since the feeding cavity of the antenna of the present invention adopts a waveguide structure, and the waveguide structure has an inherent cut-off frequency property, electromagnetic waves below the corresponding frequency cannot be transmitted therein, so the antenna of the present invention has low-frequency anti-interference capabilities; on the other hand, since the high-frequency and medium-frequency anti-interference structures of the high-frequency anti-interference rectangular blocks of the resonant layer and the medium-frequency anti-interference rectangular blocks of the resonant layer can be regarded as ideal magnetic conductors, they have a significant inhibitory effect on the propagation of electromagnetic waves in the corresponding frequency band, and have no effect on electromagnetic waves in other frequency bands outside the corresponding frequency band, so the antenna of the present invention also has medium-frequency and high-frequency anti-interference capabilities.

[0059] Simulation test verification

[0060] To verify the anti-interference capability of the circularly polarized three-band anti-interference antenna of the embodiment of the present invention, Fig.25 As shown, a simple anti-interference performance simulation model is designed. The simulation model adopts a two-port waveguide transmission structure, in which the anti-interference structure of the present invention is placed, and the electromagnetic simulation software is used to simulate and calculate the relevant performance. Fig.26 The simulation curve of the anti-interference performance of the simulation model is given. Fig.26 From the curve shown, it can be seen that the simulation model structure has anti-interference capabilities in low, medium and high frequency bands.

[0061] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A circularly polarized three-band anti-interference antenna, characterized in that: include: A waveguide feeding layer structure (10), a resonance layer structure (20), and a polarization conversion layer structure (30), wherein the waveguide feeding layer structure (10) is embedded in the middle position of the bottom of the resonance layer structure (20), and the polarization conversion layer structure (30) is tightly stacked on the top of the resonance layer structure (20); a coupling slot (103) of the waveguide feeding layer structure (10) is connected to a rectangular mounting groove (203) at the middle position of the bottom of the resonance layer structure (20); a plurality of radiation slots (202) opened on the top of the resonance layer structure (20) are connected to the lower end openings of a plurality of polarization conversion cavities (301) of the polarization conversion layer structure (30) in a one-to-one correspondence; and a plurality of groups of periodic intermediate frequency anti-interference rectangular blocks and high frequency anti-interference rectangular blocks are arranged inside the feeding cavity (101) of the waveguide feeding layer structure (10) and the resonance cavity (201) of the resonance layer structure (20).

2. The circularly polarized three-band anti-interference antenna according to claim 1, characterized in that: The front end of the feeding cavity (101) of the waveguide feeding layer structure (10) is arranged as an input opening (102) protruding from the feeding cavity (101) body, the rear end of the feeding cavity (101) is closed, and four coupling slits (103) are arranged at equal intervals along the central axis direction of the top long side of the feeding cavity (101).

3. The circularly polarized three-band anti-interference antenna according to claim 2, characterized in that: The inner bottom plate of the feed cavity (101) is provided with 8 feed layer intermediate frequency anti-interference rectangular blocks (105), 32 feed layer high frequency anti-interference rectangular blocks (106) and 4 first support base rectangular blocks (107), wherein the 8 feed layer intermediate frequency anti-interference rectangular blocks (105) are evenly divided into 4 groups, the 32 feed layer high frequency anti-interference rectangular blocks (106) are evenly divided into 4 groups, the 4 groups of feed layer intermediate frequency anti-interference rectangular blocks (105) and the 4 first support base rectangular blocks (107) are arranged at equal intervals and staggered along the long side direction of the inner bottom plate of the feed cavity (101), the 4 groups of feed layer high frequency anti-interference rectangular blocks (106) are respectively arranged on the 4 first support base rectangular blocks (107), and the height of the feed layer high frequency anti-interference rectangular blocks (106) plus the first support base rectangular blocks (107) is equal to the height of the feed layer intermediate frequency anti-interference rectangular blocks (105).

4. The circularly polarized three-band anti-interference antenna according to claim 3, characterized in that: The lower edge of the input opening (102) is flush with the top of the intermediate frequency anti-interference rectangular block (105) of the feeding layer.

5. The circularly polarized three-band anti-interference antenna according to claim 4, characterized in that: Four coupling tuning metal blocks (104) are arranged at the inner top of the feeding cavity (101), one end of the coupling tuning metal block (104) is welded to the inner top of the feeding cavity (101), and the other end of the coupling tuning metal block (104) extends downward, and the four coupling tuning metal blocks (104) are correspondingly distributed on the same side below the four coupling slits (103).

6. The circularly polarized three-band anti-interference antenna according to claim 1, characterized in that: The top of the resonant cavity (201) of the resonant layer structure (20) is provided with 16 radiation slots (202), the 16 radiation slots (202) are evenly arranged in a 4×4 array, and a rectangular mounting groove (203) is provided in the middle of the bottom of the resonant layer structure (20), the rectangular mounting groove (203) being used for embedding the waveguide feeding layer structure (10).

7. The circularly polarized three-band anti-interference antenna according to claim 6, characterized in that: The resonant layer structure (20) is symmetrical about the central axis of the rectangular installation groove (203) in the vertical direction. The bottom plate of the left half of the resonant layer structure (20) is provided with 12 resonant layer intermediate frequency anti-interference rectangular blocks (204), 48 resonant layer high frequency anti-interference rectangular blocks (205), and 4 second support base rectangular blocks (206). The 12 resonant layer intermediate frequency anti-interference rectangular blocks (204) are evenly divided into 4 groups, and the 48 resonant layer high frequency anti-interference rectangular blocks (205) are evenly divided into 4 groups. The four groups of resonance layer intermediate frequency anti-interference rectangular blocks (204) and the four second support base rectangular blocks (206) are arranged in an evenly spaced and staggered manner along the long side direction of the inner bottom plate of the left half of the resonance cavity (201); the four groups of resonance layer high frequency anti-interference rectangular blocks (205) are respectively arranged on the four second support base rectangular blocks (206); the height of the resonance layer high frequency anti-interference rectangular blocks (205) plus the height of the second support base rectangular blocks (206) is equal to the height of the resonance layer intermediate frequency anti-interference rectangular blocks (204).

8. The circularly polarized three-band anti-interference antenna according to claim 7, characterized in that: Eight radiation tuning metal blocks (207) are arranged at the inner top of the left half of the resonant cavity (201); one end of the radiation tuning metal block (207) is welded to the inner top of the resonant cavity (201); the other end of the radiation tuning metal block (207) extends downward; and the eight radiation tuning metal blocks (207) are correspondingly staggered and distributed on both sides below the eight radiation slits (202).

9. The circularly polarized three-band anti-interference antenna according to claim 1, characterized in that: The polarization conversion layer structure (30) comprises: 16 polarization conversion cavities (301), the 16 polarization conversion cavities (301) are closely combined to form a 4×4 array; the polarization conversion cavity (301) comprises: a polarization conversion cavity shell (3011), and two polarization conversion plates (3012), the polarization conversion cavity shell (3011) is a rectangular metal frame with upper and lower openings, the two polarization conversion plates (3012) are respectively vertically arranged on two inner surfaces inside the rectangular metal frame, and the two polarization conversion plates (3012) are centrally symmetrically distributed about the center of the rectangular metal frame.

10. The circularly polarized three-band anti-interference antenna according to claim 9, characterized in that: The polarization conversion plate (3012) is a trapezoidal structure, and the hypotenuse of the trapezoidal structure adopts a stepped structure.

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