Circularly polarized array antenna

Abstract

The application provides a circularly polarized array antenna, which comprises a first metal layer, a first substrate, a second metal layer, a second substrate, a third metal layer, a third substrate and a fourth metal layer which are sequentially stacked, the first metal layer is provided with a plurality of arrayed radiation patches for realizing circularly polarized radiation characteristics, a plurality of coupling slots are formed in the second substrate and penetrate the second metal layer and the third metal layer, the inner wall of the coupling slot is metallized and is in conduction with the second metal layer and the third metal layer, the coupling slot is arranged in one-to-one correspondence with the radiation patch, the third substrate is provided with a first resonant cavity which is in communication with the coupling slot, the inner wall of the first resonant cavity is metallized, and the fourth metal layer is provided with a first feeding port which is in communication with the first resonant cavity. The circularly polarized array antenna provided by the application can greatly reduce the dielectric loss caused by the medium, thereby improving the efficiency and gain of the antenna. High-order mode resonance is also realized, so that more radiation patches can be designed in a limited size, and the design of an array antenna with a larger number of antenna units is met.

Description

Technical Field

[0001] This invention belongs to the field of microwave and electromagnetic wave technology, and more specifically, relates to a circularly polarized array antenna. Background Technology

[0002] When the angle between the polarization plane of a radio wave and the normal plane of the earth changes periodically from 0 to 360°, meaning the magnitude of the electric field remains constant while its direction changes over time, and the trajectory of the end of the electric field vector projects as a circle on a plane perpendicular to the propagation direction, this is called circular polarization, and an antenna with this property is called a circularly polarized antenna. An array antenna, on the other hand, is composed of multiple identical individual antennas arranged according to a certain pattern.

[0003] Circularly polarized array antennas can be fed in two ways: The first is using a Substrate Integrated Waveguide (SIW) and aperture coupling to feed the array elements. However, as a novel form of microwave transmission line, SIW technology inevitably suffers from dielectric loss during electromagnetic wave propagation, impacting antenna radiation efficiency and gain. Furthermore, the high cost of using low-loss dielectric substrates is a significant concern. The second method uses a SIW power divider feed network, which also suffers from substantial electromagnetic wave loss during propagation. Additionally, this feeding method increases antenna size and substrate consumption, hindering antenna integration. Summary of the Invention

[0004] The purpose of this invention is to provide a circularly polarized array antenna to solve the technical problems of the large impact of dielectric loss on antenna efficiency and gain and the large size of the antenna array in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A circularly polarized array antenna is provided, comprising a first substrate, a second substrate, and a third substrate stacked sequentially. The first substrate has a first metal layer on the side facing away from the second substrate. A second metal layer is located between the first substrate and the second substrate. A third metal layer is located between the second substrate and the third substrate. The third substrate has a fourth metal layer on the side facing away from the second substrate. The first metal layer has a plurality of radiating patches arranged in an array to achieve circularly polarized radiation characteristics. The second substrate has a plurality of coupling slots, which penetrate the second metal layer and the third metal layer. The inner wall of the coupling slot is metallized and connected to the second metal layer and the third metal layer. The coupling slots and the radiating patches are arranged opposite each other. The third substrate has a first resonant cavity communicating with the coupling slots. The inner wall of the first resonant cavity is metallized. The fourth metal layer has a first feed port communicating with the first resonant cavity.

[0006] Optionally, the resonant mode TE of the first resonant cavity mn conform to Wherein, the first resonant cavity is rectangular, and its length in the x-direction is a, its length in the y-direction is b, c is the speed of light in a vacuum, and ε r f is the dielectric constant of the third substrate. c The center resonant frequency of the first resonant cavity is given, and the x and y directions are parallel to each other.

[0007] Optionally, the number of coupling slots and the number of radiating patches are both 4, and the radiating patches are arranged in a 2×2 array.

[0008] Optionally, the first resonant cavity is square, with a side length of 14.4 ± 0.5 mm, where m is 3 and n is 4.

[0009] Optionally, the center point of the first feed port is located on the center line of the first resonant cavity.

[0010] Optionally, the distance between the centers of two adjacent radiating patches is λ, where λ is the wavelength corresponding to the center resonant frequency.

[0011] Optionally, the radiating patch is circular, and slit structures are provided at both ends of the radiating patch in a first direction. The first direction is parallel to the length direction of the slit structures. The coupling groove is elongated, and the first direction is set at an angle to the length direction of the coupling groove.

[0012] Optionally, the angle between the first direction and the length direction of the coupling groove is 75±5°.

[0013] Optionally, the diameter of the radiating patch is 0.54λ, and the width of the slit structure is 0.08λ*0.23λ, where λ is the wavelength corresponding to the center frequency.

[0014] Optionally, the circularly polarized array antenna further includes a fourth substrate, a fifth substrate, and a sixth substrate stacked sequentially. The fourth metal layer is disposed on the side of the fourth substrate facing away from the fifth substrate. A fifth metal layer is also disposed between the fourth substrate and the fifth substrate. A sixth metal layer is also disposed between the fifth substrate and the sixth substrate. A seventh metal layer is also disposed on the side of the sixth substrate facing away from the fifth substrate. A second feed port is formed on the fourth substrate, penetrating the fifth metal layer and facing the first feed port. The inner wall of the second feed port is metallized. The fifth substrate has a second resonant cavity communicating with the second feed port. A waveguide input port communicating with the second resonant cavity is formed on the sixth substrate. The inner wall of the waveguide input port is metallized. The circularly polarized array antenna has a flange mounting hole penetrating the fourth substrate, the fifth substrate, and the sixth substrate.

[0015] The beneficial effects of the circularly polarized array antenna provided by this invention are as follows: Compared with the prior art, the circularly polarized array antenna of this invention includes a first substrate, a second substrate, and a third substrate stacked sequentially. The first substrate has a first metal layer and a second metal layer on opposite sides, respectively. The first metal layer has multiple radiating patches for realizing circularly polarized radiation characteristics. The second substrate has coupling slots corresponding to each radiating patch. The third substrate has a first resonant cavity. Feeding is achieved through a first feed port connected to the first resonant cavity, generating resonance within the cavity. Electromagnetic waves are then transmitted to the radiating patches through the coupling slots, thus feeding the radiating patches. Since the first resonant cavity is filled with air, dielectric loss due to the medium can be significantly reduced, thereby improving the antenna's efficiency and gain. Furthermore, by designing the first resonant cavity, higher-order mode resonance can be achieved, generating more current zeros within a smaller size range. This allows for the design of more radiating patches within a limited size, enabling the feeding of more radiating patches and satisfying the design of array antennas with a larger number of antenna elements. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1This is a schematic diagram of the exploded structure of the first type of circularly polarized array antenna provided in an embodiment of the present invention;

[0018] Figure 2 A front view of the first metal layer provided in an embodiment of the present invention;

[0019] Figure 3 A front view of the second substrate provided in an embodiment of the present invention;

[0020] Figure 4 This is an exploded view of the second type of circularly polarized array antenna provided in an embodiment of the present invention;

[0021] Figure 5 This is a cross-sectional view of a second type of circularly polarized array antenna provided in an embodiment of the present invention;

[0022] Figure 6 This is a diagram showing the electric field distribution within the first resonant cavity in an embodiment of the present invention.

[0023] Figure 7 for Figure 4 S of the middle antenna 11 Comparison graphs of parameter simulation and experiments;

[0024] Figure 8 for Figure 4 Simulation and experimental comparison curves of antenna gain and radiation efficiency;

[0025] Figure 9 for Figure 4 Normalized radiation pattern of antenna simulation and experiment.

[0026] The following are the labeling elements in the figure:

[0027] 11-First substrate; 12-Second substrate; 121-Coupled groove; 13-Third substrate; 131-First resonant cavity; 14-Fourth substrate; 141-Second feed port; 15-Fifth substrate; 151-Second resonant cavity; 16-Sixth substrate; 161-Waveguide input port; 21-First metal layer; 211-Blank area; 212-Radiating patch; 213-Slit structure; 22-Second metal layer; 23-Third metal layer; 24-Fourth metal layer; 241-First feed port; 25-Fifth metal layer; 26-Sixth metal layer; 27-Seventh metal layer; 3-Flange mounting hole. Detailed Implementation

[0028] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0029] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0030] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] The circularly polarized array antenna provided in the embodiments of the present invention will now be described.

[0033] Please refer to the following: Figures 1 to 3 The circularly polarized array antenna includes a first substrate 11, a second substrate 12, and a third substrate 13 stacked sequentially. The first substrate 11 has a first metal layer 21 on the side facing away from the second substrate 12, a second metal layer 22 is located between the first substrate 11 and the second substrate 12, a third metal layer 23 is located between the second substrate 12 and the third substrate 13, and a fourth metal layer 24 is located on the side of the third substrate 13 facing away from the second substrate 12. That is, the first metal layer 21, the first substrate 11, the second metal layer 22, the second substrate 12, the third metal layer 23, the third substrate 13, and the fourth metal layer 24 are stacked sequentially.

[0034] The first metal layer 21 has multiple radiating patches 212, which are arranged in an array, such as a 1×4 array, a 2×2 array, or a 2×3 array. The radiating patches 212 are used to achieve circularly polarized radiation characteristics, giving the antenna circular polarization.

[0035] The second substrate 12 has multiple coupling slots 121, the number of which is the same as the number of radiating patches 212. Each coupling slot 121 is positioned directly opposite the corresponding radiating patch 212 and is used to power the radiating patch 212. The coupling slots 121 penetrate the second metal layer 22 and the third metal layer 23, and the second metal layer 22 and the third metal layer 23 have openings with the same shape as the coupling slots 121. Simultaneously, the inner walls of the coupling slots 121 are metallized and are electrically connected to both the second metal layer 22 and the third metal layer 23.

[0036] The third substrate 13 has a first resonant cavity 131, which is connected to the coupling slot 121. The inner wall of the first resonant cavity 131 is metallized and connected to the third metal layer 23. Furthermore, a first feed port 241 is formed on the fourth metal layer 24, which is connected to the first resonant cavity 131. In this embodiment, the antenna is fed at the first feed port 241 and achieves high-order mode resonance in the first resonant cavity 131. The coupling slot 121 is located near or at the current zero point, thereby feeding the radiating patch 212 through the coupling slot 121, achieving circular polarization of the array antenna.

[0037] The circularly polarized array antenna in the above embodiment includes a first substrate 11, a second substrate 12, and a third substrate 13 stacked sequentially. The first substrate 11 has a first metal layer 21 and a second metal layer 22 on opposite sides. The first metal layer 21 has multiple radiating patches 212 for achieving circularly polarized radiation characteristics. The second substrate 12 has coupling slots 121 corresponding to each radiating patch 212. The third substrate 13 has a first resonant cavity 131. The antenna is fed through a first feed port 241 connected to the first resonant cavity 131, generating resonance within the cavity. Electromagnetic waves are then transmitted to the radiating patches 212 through the coupling slots 121, thus feeding the patches. Since the first resonant cavity 131 is filled with air, dielectric loss due to the dielectric material is significantly reduced, thereby improving the antenna's efficiency and gain. In addition, by designing the first resonant cavity 131, higher-order mode resonance can be achieved, generating more current zeros within a smaller size range. This allows for the design of more radiating patches 212 within a limited size, enabling the feeding of more radiating patches 212 and satisfying the design of array antennas with a larger number of antenna elements.

[0038] Optionally, a plurality of blank regions 211 are formed on the first metal layer 21, and each blank region 211 contains the aforementioned radiating patch 212. The first metal layer 21 is deposited on the first substrate 11. In this way, by setting blank regions 211, less metal needs to be etched; only the metal around the radiating patch 212 needs to be etched to form the blank regions 211.

[0039] In one embodiment of the present invention, please refer to Figure 1 The first resonant cavity 131 is rectangular, with a length of 'a' in the x-direction and 'b' in the y-direction. The x-direction and y-direction are parallel to each other. The resonant mode of the first resonant cavity 131 is TE. mn It conforms to the following formula:

[0040]

[0041] Where c is the speed of light in a vacuum, ε r f is the dielectric constant of the third substrate 13. c The center resonant frequency of the first resonant cavity 131 is 131.

[0042] Therefore, the mode distribution satisfied by the resonant cavity can be designed according to the number and arrangement of the array elements (radiating patches 212), and the initial parameters of the resonant cavity can be calculated accordingly. Before designing the array arrangement of the radiating patches 212, the cavity mode of the first resonant cavity 131 is simulated and verified, and the distribution mode of its internal field is used to determine whether it supports the required array (two-dimensional planar array or linear array). At the same time, the specific a and b corresponding to different field distribution modes of the first resonant cavity 131 proposed in this invention can also be calculated using the above formula, and realized through a reasonable excitation method (e.g., using the above-mentioned coupling slot 121 experiment). For example, TE 41 The pattern is applicable to 4×1 linear arrays. Therefore, TE mn The first resonant cavity 131 of the mode can complete the feeding of the m×n antenna array element (radiating patch 212).

[0043] In one embodiment of the present invention, please refer to Figure 1 and Figure 2 There are four radiating patches 212 and four corresponding coupling slots 121. The four radiating patches 212 form a 2×2 array antenna, and the four coupling slots 121 are also arranged in a 2×2 array.

[0044] In order to make the size of the array antenna smaller, it is necessary to excite higher-order modes in the first resonant cavity 131 to form a sufficient number of current zeros to facilitate the arrangement of the corresponding radiating patches 212.

[0045] For example, Figure 2 The proposed 2×2 antenna array, through TE excitation 34 The field distribution of the mode is used to feed the antenna array, such as Figure 6The diagram shows the electric field distribution in the first resonant cavity 131. Based on this, the first resonant cavity 131 is configured as a square, with a side length of 14.4 ± 0.5 mm, such as 14.1 mm, 14.4 mm, or 14.5 mm, to excite a TE signal within the first resonant cavity 131. 34 In this embodiment, the electric field distribution within the first resonant cavity 131 is as follows: Figure 6 As shown. Figure 6 The box in the figure represents the projection of the coupling slot 121 onto the viewpoint of this figure, that is, the coupling slot 121 is positioned directly opposite the zero current point. The diameter of the radiating patch 212 can be 3.95 mm, and the distance between two adjacent radiating patches 212 can be 0.1 mm to 0.4 mm.

[0046] Optionally, the center point of the first feed port 241 is located on the center line of the first resonant cavity 131, so that a centrally symmetrical electric field can be excited inside the first resonant cavity 131, which facilitates feeding the array antenna.

[0047] It should be noted that in the above embodiment, the 2×2 antenna array uses the TE of the first resonant cavity 131. 34 Feeding the mode to it presents the following challenges: First, a suitable location needs to be selected as the feed port to feed the first resonant cavity 131; second, a suitable size for the first resonant cavity 131 needs to be selected so that a TE can be excited within the first resonant cavity 131. 34 Mode, TE 34 The mode needs to have enough current zero points, the number of current zero points should be greater than or equal to the number of radiating elements, and a suitable current zero point should be selected to design the coupling slot 121, which can accommodate the radiating elements without causing the antenna array to be too large.

[0048] In one embodiment of the present invention, please refer to Figure 2 and Figure 3 The distance between the centers of two adjacent radiating patches 212 is λ, where λ is the wavelength corresponding to the center resonant frequency. This allows the array antenna composed of multiple radiating patches 212 to have high efficiency and gain. Correspondingly, the distance between the centers of two adjacent coupling slots 121 is also λ.

[0049] The first power supply port 241 is rectangular, and the coupling slot 121 is also rectangular. The length direction of the first power supply port 241 and the length direction of the coupling slot 121 are parallel to each other.

[0050] In one embodiment of the present invention, please refer to Figure 2The radiating patch 212 is circular, and each end of the radiating patch 212 has a slit structure 213, which is parallel to the length direction of the slit structure 213 in the first direction. That is, each radiating patch 212 has two slit structures 213, and the center line of each slit structure 213 passes through the center of the radiating patch 212.

[0051] Optionally, the coupling groove 121 is elongated, with its length direction parallel to the x-direction, and a first direction forming an angle with the length direction of the coupling groove 121, such that the first direction forms an angle with the x-direction. In this way, the magnetic components generated by the radiating patch 212 can be decomposed into magnetic components along the x-direction and magnetic components along the y-direction, thus achieving circular polarization.

[0052] Optionally, the angle between the first direction and the length direction of the coupling slot 121 is 75±5°, that is, the angle between the first direction and the x-direction is 75±5°, such as 70°, 73°, 75°, 77°, etc. In this way, the magnitude and phase of the magnetic components in the x-direction and y-direction are close to the same, and the circular polarization effect of the antenna is better. Specifically, since the length direction of the coupling slot 121 is parallel to the x-direction, it already has a certain initial magnetic component in the x-direction. By setting the angle between the first direction and the x-direction to 75±5°, the magnetic component generated by the radiating patch 212 can have a smaller magnetic component in the x-direction and a larger magnetic component in the y-direction. In this way, the magnetic component in the x-direction, when added to the initial magnetic component, will be equivalent to the magnetic component in the y-direction, resulting in a better circular polarization effect.

[0053] Optionally, please refer to Figure 2 The radiating patch 212 has a diameter of 0.54λ, and the slit structure 213 has a width of 0.08λ * 0.23λ, where λ is the wavelength corresponding to the center frequency. This allows the circularly polarized array antenna to have high efficiency and gain.

[0054] In other embodiments of the present invention, the circular polarization radiation characteristics can also be achieved using radiation patches 212 with other structures. For example, a rectangular patch can be used as the radiation structure, at a 45° angle to the coupling groove 121 to achieve circular polarization characteristics. The rectangular patch can also be replaced with a dipole, a semi-circular, or a trapezoidal radiation patch as the radiation structure.

[0055] In one embodiment of the present invention, please refer to Figure 4 and Figure 5The circularly polarized array antenna also includes a fourth substrate 14, a fifth substrate 15, and a sixth substrate 16 stacked sequentially. A fourth metal layer 24 is disposed on the side of the fourth substrate 14 facing away from the fifth substrate 15. A fifth metal layer 25 is disposed between the fourth substrate 14 and the fifth substrate 15. A sixth metal layer 26 is disposed between the fifth substrate 15 and the sixth substrate 16. A seventh metal layer 27 is disposed on the side of the sixth substrate 16 facing away from the fifth substrate 15. That is, the fourth metal layer 24, the fourth substrate 14, the fifth metal layer 25, the fifth substrate 15, the sixth metal layer 26, the sixth substrate 16, and the seventh metal layer 27 are arranged sequentially at intervals.

[0056] A second power supply port 141 is formed on the fourth substrate 14. The second power supply port 141 is the same size as the first power supply port 241 and is positioned opposite each other. One end of the second power supply port 141 is connected to the first resonant cavity 131, and the other end is connected to the second resonant cavity 151 on the fifth substrate 15. The second power supply port 141 penetrates the fourth metal layer 24, that is, the fourth metal layer 24 has an opening of the same size and facing the second power supply port 141. The inner wall of the second power supply port 141 is metallized, so that the fourth metal layer 24 and the fifth metal layer 25 are connected through the inner metal wall of the second power supply port 141.

[0057] The second resonant cavity 151, as described above, is formed on the fifth substrate 15. The second resonant cavity 151 penetrates the fifth metal layer 25 and communicates with the second feed port 141. The inner wall of the second resonant cavity 151 is metallized. The arrangement of the second resonant cavity 151 can significantly reduce the loss caused by the dielectric, thereby improving the efficiency and gain of the antenna.

[0058] A waveguide input port 161 communicating with the second resonant cavity 151 is provided on the sixth substrate 16. The waveguide input port 161 penetrates the sixth metal layer 26 and the seventh metal layer 27, and the inner wall of the waveguide input port 161 is metallized.

[0059] In this way, a converter from the waveguide to the first resonant cavity 131 can be formed. The waveguide is connected to the waveguide input port 161, which facilitates feeding the circularly polarized array antenna through the waveguide.

[0060] Optionally, flange mounting holes 3 are provided on the fourth substrate 14, the fifth substrate 15 and the sixth substrate 16 to facilitate the positioning of the fourth substrate 14, the fifth substrate 15 and the sixth substrate 16.

[0061] Optionally, the circularly polarized array antenna is used to connect to the WR-22 waveguide. The position and size of the flange mounting holes 3 in the fourth substrate 14, the fifth substrate 15, and the sixth substrate 16 refer to the flange standard within the operating frequency range, which is 33-50.1 GHz, according to the UG-383 / U standard.

[0062] Optionally, the fourth substrate 14, the fifth substrate 15, and the sixth substrate 16 can be fixed by screws or the like. The first substrate 11, the second substrate 12, the third substrate 13, and the fourth substrate 14 can also be fixed by screws. Screw fixing minimizes the impact of air gaps between substrates on antenna power transmission.

[0063] Optionally, during the forming process, the first metal layer 21 is attached to the surface of the first substrate 11, the second metal layer 22 and the third metal layer 23 are respectively attached to opposite sides of the second substrate 12, the fourth metal layer 24 and the fifth metal layer 25 are respectively attached to opposite sides of the fourth substrate 14, and the sixth metal layer 26 and the seventh metal layer 27 are respectively attached to opposite sides of the sixth substrate 16.

[0064] To verify this invention, the applicant conducted [the following investigations / tests]. Figure 4 The provided embodiments were tested and simulated. The main dimensional parameters corresponding to the tests and simulations are as follows:

[0065] The first metal layer 21 has a length of 30 mm in the x-direction and a length of 20 mm in the y-direction. The blank area 211 has a length of 6.7 mm in the x-direction and a length of 5.8 mm in the y-direction. The spacing between the two blank areas 211 in the x-direction is 0.3 mm, and the spacing between the two blank areas 211 in the y-direction is 0.2 mm. The diameter of the radiating patch 212 is 3.95 mm. The width of the slit structure 213 is 0.6 mm, and the length of the slit structure 213 is 1.68 mm.

[0066] The coupling groove 121 has a length of 4.7 mm and a width of 1 mm, and the distance between the centers of the two coupling grooves 121 in the x direction is 5.85 mm.

[0067] The first resonant cavity 131 is square with a side length of 14.4 mm. The first feed port 241 has a length of 4 mm and a width of 1.2 mm. The second resonant cavity 151 has a length of 39.2 mm and a width of 9.6 mm.

[0068] The first substrate is made of Rogers RT 5880, with a relative permittivity of 2.2 and a loss tangent of 0.0009. The remaining five substrates are all made of FR4.

[0069] Regarding its operating bandwidth, 3-dB axial ratio, and gain, [the following information is provided]. Figure 7 and Figure 8 The measurements are given separately. The measured -10dB impedance bandwidth is 19.58%, from 36.85 to 44.85 GHz. The measured 3-dB axial ratio bandwidth is 5.74% (42-44.5 GHz). The measured peak gain is 14.02 dBic. Figure 9 The normalized radiation patterns of the array antenna in the E-plane and H-plane at 42 GHz are given.

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A circularly polarized array antenna, characterized in that: The system includes a first substrate, a second substrate, and a third substrate stacked sequentially. The first substrate has a first metal layer on the side facing away from the second substrate. A second metal layer is located between the first substrate and the second substrate. A third metal layer is located between the second substrate and the third substrate. The third substrate has a fourth metal layer on the side facing away from the second substrate. The first metal layer has a plurality of arrayed radiating patches for realizing circularly polarized radiation characteristics. The second substrate has a plurality of coupling grooves that penetrate the second metal layer and the third metal layer. The inner wall of the coupling groove is metallized and connected to the second metal layer and the third metal layer. The coupling grooves and the radiating patches are arranged opposite each other. The third substrate has a first resonant cavity that communicates with the coupling grooves. The inner wall of the first resonant cavity is metallized. The fourth metal layer has a first feed port that communicates with the first resonant cavity. The circularly polarized array antenna further includes a fourth substrate, a fifth substrate, and a sixth substrate stacked sequentially. A fourth metal layer is disposed on the side of the fourth substrate facing away from the fifth substrate. A fifth metal layer is disposed between the fourth substrate and the fifth substrate. A sixth metal layer is disposed between the fifth substrate and the sixth substrate. A seventh metal layer is disposed on the side of the sixth substrate facing away from the fifth substrate. A second feed port is formed on the fourth substrate, penetrating the fifth metal layer and facing the first feed port. The inner wall of the second feed port is metallized. The fifth substrate has a second resonant cavity communicating with the second feed port. A waveguide input port communicating with the second resonant cavity is formed on the sixth substrate. The inner wall of the waveguide input port is metallized. The circularly polarized array antenna has a flange mounting hole penetrating the fourth substrate, the fifth substrate, and the sixth substrate.

2. The circularly polarized array antenna as described in claim 1, characterized in that: The resonant mode of the first resonant cavity TE mn conform to The first resonant cavity is rectangular, and the first resonant cavity is in... x The length of the direction is a ,exist y The length of the direction is b , c It is the speed of light in a vacuum. ε r It is the dielectric constant of the third substrate. f c The center resonant frequency of the first resonant cavity is... x direction and y The directions are parallel to each other.

3. The circularly polarized array antenna as described in claim 2, characterized in that: The number of coupling slots and the number of radiating patches are both 4, and the radiating patches are arranged in a 2×2 array.

4. The circularly polarized array antenna as described in claim 3, characterized in that: The first resonant cavity is square, and its side length is 14.4 ± 0.5 mm. m It is 3. n The value is 4.

5. The circularly polarized array antenna as described in claim 4, characterized in that: The center point of the first power supply port is located on the center line of the first resonant cavity.

6. The circularly polarized array antenna as described in claim 3, characterized in that: The distance between the centers of two adjacent radiation patches is λ ,in, λ The wavelength corresponds to the center resonant frequency.

7. The circularly polarized array antenna as described in claim 1, characterized in that: The radiating patch is circular, and slit structures are provided at both ends of the radiating patch in a first direction. The first direction is parallel to the length direction of the slit structures. The coupling groove is elongated, and the first direction is set at an angle to the length direction of the coupling groove.

8. The circularly polarized array antenna as described in claim 7, characterized in that: The angle between the first direction and the length direction of the coupling groove is 75±5º.

9. The circularly polarized array antenna as described in claim 7, characterized in that: The diameter of the radiation patch is 0.54 mm. λ The width of the slit structure is 0.

08. λ *0.23 λ ,in, λ The wavelength corresponds to the center frequency.

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