A dual circularly polarized phased array antenna applied to satellite communication

Abstract

The application discloses a kind of dual circular polarization phased array antennas applied to satellite communication, including the n×m antenna unit groups formed antenna array according to n rows m column non-interval arrangement, each antenna unit group includes 4 antenna units according to 2 rows 2 column non-interval arrangement, each antenna unit includes feed network and radiation network, radiation network includes radiation patch structure and the metal column structure arranged in the lower surface of radiation patch structure, radiation patch structure adopts magnetic electric dipole structure, radiation patch structure and metal column structure jointly constitute current transmission path, feed network includes 3dB directional coupler and two г type feed structures, two г type feed structures are orthogonal distribution, 3dB directional coupler is realized using multi-section corrugated symmetrical directional coupling structure capable of realizing step-by-step impedance matching;Advantages are that scanning angle is larger, can reach ±60 °, and bandwidth is wider, can reach 30% and above.

Description

Technical Field

[0001] This invention relates to dual-circularly polarized phased array antennas, and more particularly to a dual-circularly polarized phased array antenna for use in satellite communications. Background Technology

[0002] Dual-circular polarized phased array antennas are an advanced communication and detection antenna technology. With the rapid development of wireless communication and satellite technology, the performance requirements for antennas are constantly increasing. Dual-circular polarized phased array antennas can simultaneously achieve left-hand and right-hand circular polarization, effectively suppressing multipath attenuation and rain / fog attenuation, improving the stability and anti-interference capability of signal transmission. They are widely used in satellite communication, radar detection, electronic countermeasures, and other fields, meeting engineering requirements such as wide beamwidth, wide-angle scanning, and low profile.

[0003] Existing dual-circular polarization phased array antennas are usually designed based on array structures, which mainly consist of multiple antenna elements arranged in an array. By controlling the phase and amplitude of each antenna element, rapid beam scanning, beamforming, or multi-beam generation can be achieved. Reference [1] R. Banerjee et al., "A 22–28 GHz Polarization-Reconfigurable Flat-Panel 8 × 8 Tx / Rx Phased Array Antenna With Uniquely Arranged Novel Radiating Elements for CubeSat Communication," in IEEE Transactions on Antennas and Propagation, vol. 71, no. 5, pp. 4138-4152, May 2023, doi:10.1109 / TAP.2023.3249820. proposes a phased array antenna for satellite communication. This phased array antenna can transmit and receive dual-circular polarized radio frequency signals and achieves good polarization performance and a certain scanning capability in a specific frequency band. However, its relatively narrow operating bandwidth limits its application in a wider frequency band. In addition, the scanning angle of this phased array antenna is also relatively limited, which cannot meet the requirements of large-angle scanning, thus affecting its applicability in complex communication environments to some extent. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a dual circularly polarized phased array antenna for satellite communication with a large scanning angle of ±60° and a wide bandwidth of 30% or more.

[0005] The technical solution adopted by this invention to solve the above-mentioned technical problems is as follows: a dual-circularly polarized phased array antenna for satellite communication, comprising n×m antenna element groups arranged in an n-row m-column array without gaps, where × is the multiplication operator, and n and m are integers greater than or equal to 2; each antenna element group includes 4 antenna elements arranged in a 2-row 2-column array without gaps, and when any antenna element is rotated 90°, 180°, and 270° clockwise around a certain axis, it will successively coincide with the other three antenna elements; each antenna element includes a feed network and a radiation network; the radiation network is used to receive a mixed signal of left-hand circularly polarized radio frequency signals and right-hand circularly polarized radio frequency signals in free space, and The system feeds into the feeding network, or receives orthogonal two-path polarized radio frequency signals fed into the feeding network, and combines these two-path polarized radio frequency signals into a mixed signal of left-hand circularly polarized radio frequency signal and right-hand circularly polarized radio frequency signal, which is then radiated into free space. The feeding network receives radio frequency signals transmitted from the front-end equipment and converts them into orthogonal two-path polarized radio frequency signals before feeding them into the radiation network, or converts the mixed signal of left-hand circularly polarized radio frequency signals and right-hand circularly polarized radio frequency signals fed into the radiation network into orthogonal two-path polarized radio frequency signals before transmitting them to the back-end equipment. The radiation network includes a radiating patch structure, which employs a magnetoelectric dipole structure. The radiation network also includes... The system includes a metal pillar structure disposed on the lower surface of the radiating patch structure; the radiating patch structure and the metal pillar structure together constitute a current transmission path; the feeding network includes a 3dB directional coupler and two г-shaped feeding structures, which are orthogonally distributed; the 3dB directional coupler is implemented using a multi-section equiripple symmetrical directional coupling structure capable of achieving step-by-step impedance matching; when the radiating network receives a mixed signal of left-hand circularly polarized RF signal and right-hand circularly polarized RF signal in free space, the current transmission path couples the mixed signal to the two г-shaped feeding structures respectively, and each г-shaped feeding structure converts the mixed signal at its location into a linearly polarized RF signal, forming two orthogonal linearly polarized radiating networks. The frequency signal is fed into the 3dB directional coupler, which combines the two line-polarized RF signals into a single RF signal for transmission to the back-end device. When the front-end device transmits the RF signal to the feed network, the 3dB directional coupler splits the RF signal into two RF signals with a 90° phase difference, and feeds them into two г-type feed structures respectively. The two г-type feed structures convert the RF signals at their respective locations into linearly polarized RF signals, forming two orthogonal line-polarized RF signals coupled to the current transmission path. The two orthogonal line-polarized RF signals are combined on the current transmission path into a mixed signal of left-hand circularly polarized RF signal and right-hand circularly polarized RF signal, which is then radiated into free space.

[0006] Compared with existing technologies, the advantages of the antenna of the present invention are as follows: By setting a metal pillar structure on the lower surface of the radiating patch structure, the metal pillar structure and the radiating patch structure jointly form a current transmission path. Since the metal pillar structure is below the radiating patch structure, it expands the current transmission path without affecting the upper surface area of ​​the radiating patch structure. Therefore, under the same transmission surface area requirement, the surface area of ​​the radiating patch structure can be reduced, thereby reducing the antenna element radiating aperture, widening the beamwidth for low-frequency signal transmission, significantly improving the gain drop during large-angle scanning, and making the antenna scanning angle larger; the 3dB directional coupler is implemented using a multi-section equi-corrugated symmetrical directional coupling structure, enabling the internal structure of the 3dB directional coupler to... By achieving step-by-step impedance matching, excellent impedance matching performance is achieved, resulting in minimal loss of RF signals during transmission through the 3dB directional coupler. This ensures that the phase difference of RF signals fed from the 3dB directional coupler into the two g-type feed structures remains stable at 90° throughout the entire operating frequency band, with a reflection coefficient of less than -10dB. This guarantees efficient energy transmission and stable circular polarization performance, extending the antenna's bandwidth. Experimental simulation results show that the dual circularly polarized phased array antenna of this invention, applied to satellite communication, can achieve a bandwidth of 30%, an antenna scanning angle of ±60°, and at the maximum scanning angle, a low-frequency gain drop of less than 3dB and a high-frequency gain drop of less than 5dB, exhibiting significant high-gain characteristics within the scanning region.

[0007] Furthermore, the radiation network also includes a first dielectric plate, a second dielectric plate, and a first metal ground. Both the first and second dielectric plates are cuboid structures, with their lengths along the front-to-back direction, widths along the left-to-right direction, and thicknesses along the top-to-bottom direction. The first dielectric plate, the second dielectric plate, and the first metal ground are stacked sequentially from top to bottom, and are aligned vertically in the front, back, left, and right directions, respectively. The first metal ground is attached to the lower surface of the second dielectric plate. The radiation patch structure includes a first radiating sheet, a second radiating sheet, a third radiating sheet, and a fourth radiating sheet. All four radiating sheets are attached to the upper surface of the first dielectric plate. The first, second, third, and fourth radiating sheets are spaced horizontally and vertically, respectively. The first dielectric plate is then positioned along the top... The downward-direction central axis is called the first axis; the first axis is located in the gap between the first radiating plate, the second radiating plate, the third radiating plate, and the fourth radiating plate; if the first radiating plate rotates about the first axis as its axis, rotating clockwise by 90°, 180°, and 270°, it will successively coincide with the second radiating plate, the fourth radiating plate, and the third radiating plate; the first radiating plate is formed by opening a first rectangular groove and a second rectangular groove on a first square metal sheet, with the two adjacent sides of the first square metal sheet along the front-back direction and the left-right direction, respectively; the right front corner and left rear corner of the first square metal sheet are rounded, the first rectangular groove is close to the right side of the first square metal sheet, and the second rectangular groove is close to the rear side of the first square metal sheet; if the second rectangular groove rotates 90° counterclockwise about the center line of the first square metal sheet as its axis, it will completely coincide with the first rectangular groove.

[0008] Furthermore, the metal pillar structure includes a first metal pillar group, a second metal pillar group, a third metal pillar group, and a fourth metal pillar group; the first metal pillar group is located below the first radiating sheet and near the left front corner of the first square metal sheet; the first metal pillar group includes five metal pillars arranged in an L-shape with equal spacing, all five metal pillars penetrating vertically through the first dielectric plate, with their top surfaces adhering to the lower end surface of the first square metal sheet and their bottom surfaces flush with the lower surface of the first dielectric plate; if the first metal pillar group rotates clockwise by 90°, 180°, and 270° about the first axis, it will successively overlap with the second metal pillar group, the fourth metal pillar group, and the third metal pillar group.

[0009] Furthermore, the radiation network also includes four forward gain structures: a first forward gain structure, a second forward gain structure, a third forward gain structure, and a fourth forward gain structure. The first forward gain structure is located below the first square metal sheet and near its right rear corner. The first forward gain structure includes three equally spaced metal pillars arranged in an L-shape. All three metal pillars penetrate vertically through the first dielectric plate and the second dielectric plate, with their top surfaces aligned with the lower end face of the first square metal sheet and their bottom surfaces flush with the lower surface of the second dielectric plate. The middle metal pillar has a through-hole coaxially formed, which is filled with dielectric material. If the first forward gain structure is rotated clockwise by 90°, 180°, and 270° around the first axis, it will sequentially overlap with the second, fourth, and third forward gain structures.

[0010] Furthermore, the power supply network also includes a third dielectric plate, a fourth dielectric plate, and a second metal ground; the third dielectric plate, the fourth dielectric plate, and the second metal ground are all cuboid structures, with their lengths along the front-to-back direction, their widths along the left-to-right direction, and their thicknesses along the top-to-bottom direction; the third dielectric plate, the fourth dielectric plate, and the second metal ground are arranged sequentially from top to bottom below the first metal ground, and the four are aligned vertically and horizontally respectively; the upper surface of the third dielectric plate is attached to the lower surface of the first metal ground; the second metal ground is attached to the lower surface of the fourth dielectric plate; there is a gap between the third dielectric plate and the fourth dielectric plate, and the 3dB directional coupler is disposed between the third dielectric plate and the fourth dielectric plate.

[0011] Furthermore, the two г-shaped feeding structures are a first г-shaped feeding structure and a second г-shaped feeding structure, respectively. The first г-shaped feeding structure includes a first metal wire, a first metal pillar, and a second metal pillar. The first metal wire is attached to the upper surface of the first dielectric substrate and extends from the gap between the first and third radiating plates to the gap between the second and fourth radiating plates, and is symmetrical about the first axis. The first metal wire does not contact the first, second, third, or fourth radiating plates. The first metal pillar vertically penetrates the first dielectric substrate and the second dielectric substrate. The structure comprises a substrate, a first metal ground, and a third dielectric substrate; the first metal pillar is not in contact with the first metal ground, and its top surface contacts the bottom left end of the first metal wire, while its bottom end is flush with the lower surface of the third dielectric substrate; the second metal pillar vertically penetrates the first dielectric substrate, and its top surface contacts the bottom right end of the first metal wire, while its bottom end is flush with the lower surface of the first dielectric substrate; the second G-shaped feed structure includes a second metal wire, a third metal wire, a fourth metal wire, a third metal pillar, a fourth metal pillar, a fifth metal pillar, and a sixth metal pillar, wherein the second metal wire, the third metal wire, and the fourth metal wire all extend forward and backward; the second metal wire is attached to the first... The first metal wire is attached to the upper surface of a dielectric substrate, located in the gap between the third and fourth radiating sheets, and behind the first metal wire; the fourth metal wire is attached to the upper surface of the first dielectric substrate, located in the gap between the first and second radiating sheets, and in front of the first metal wire; the fourth and second metal wires are symmetrical about the first axis; the third metal wire is attached to the upper surface of the second dielectric substrate and is symmetrical about the first axis; the third metal wire vertically penetrates the first dielectric substrate, the second dielectric substrate, the first metal ground, the third dielectric substrate, and the 3dB fixed point. The coupling consists of a third metal post that does not contact the first metal ground and whose top surface is attached to the bottom rear end of the second metal wire, and whose bottom surface is attached to the top surface of the fourth dielectric plate. The fourth, fifth, and sixth metal posts all penetrate the first dielectric plate vertically. The top surface of the fourth metal post is attached to the bottom front end of the second metal wire, and its bottom surface is attached to the top rear end of the third metal wire. The top surface of the fifth metal post is attached to the bottom rear end of the fourth metal wire, and its bottom surface is attached to the top front end of the third metal wire. The top surface of the sixth metal post is attached to the bottom front end of the fourth metal wire, and its bottom surface is flush with the lower surface of the first dielectric plate.

[0012] Furthermore, the 3dB directional coupler includes a layer of PP board, a first tapered metal wire, and a second tapered metal wire; the PP board is of a cuboid structure and is disposed between the third dielectric board and the fourth dielectric board, and the three are aligned in the front, back, left, right, up, and down directions; the upper surface of the PP board is in contact with the lower surface of the third dielectric board, and the lower surface of the PP board is in contact with the upper surface of the fourth dielectric board; the third metal column penetrates through the PP board at the same time and is not in contact with either the first tapered metal wire or the second tapered metal wire; a first type of "Ji" - shaped groove is formed on the upper end surface of the PP board, and the first tapered metal wire is a "Ji" - shaped wire formed by connecting multiple metal wires with dislocation and is disposed in the first type of "Ji" - shaped groove, just filling the first type of "Ji" - shaped groove; a second type of "Ji" - shaped groove is formed on the lower end surface of the PP board, and the second tapered metal wire is a "Ji" - shaped wire formed by connecting multiple metal wires with dislocation and is disposed in the second type of "Ji" - shaped groove, just filling the second type of "Ji" - shaped groove; the line connecting the left - rear top corner and the right - front top corner of the upper end surface of the PP board is called the second axis; if both the first tapered metal wire and the second tapered metal wire are perpendicularly mapped onto the upper end surface of the PP board, the second tapered metal wire and the first tapered metal wire will be symmetric about the second axis and have two overlapping portions, and the electrical length of each overlapping portion is one - eighth wavelength.

[0013] Furthermore, the first gradient metal line comprises thirteen sequentially connected metal segments, namely, segment 1, segment 2, segment 3, segment 4, segment 5, segment 6, segment 7, segment 8, segment 9, segment 10, segment 11, segment 12, and segment 13. The first segment extends from one end to the left rearward, with its other end offset from one end of the second segment. The second segment extends from one end to the right rearward, perpendicular to the first segment. One end of the third segment offsets to the left rearward and connects to the other end of the second segment. One end of the fourth segment offsets to the left rearward and connects to the other end of the third segment. One end of the fifth segment offsets to the left rearward and connects to the other end of the fourth segment. One end of the sixth segment offsets to the left rearward and connects to the other end of the fifth segment. One end of the seventh segment offsets to the left rearward and connects to the other end of the sixth segment. The eighth segment is offset to the left and rear, connecting with the other end of the seventh segment. The eighth segment is perpendicular to the seventh segment and extends to the left and rear. The ninth segment is connected to the other end of the eighth segment. The ninth segment is perpendicular to the eighth segment and extends to the left and front. The tenth segment is connected to the other end of the ninth segment. The tenth segment is perpendicular to the ninth segment and extends to the left and rear. The eleventh segment is connected to the other end of the tenth segment. The eleventh segment is perpendicular to the tenth segment and extends to the left and front. A triangular chamfer structure is formed on the outer side of the connection between the tenth and eleventh segments. The twelfth segment is offset to the left and rear, connecting with the other end of the eleventh segment. The thirteenth segment is connected to the other end of the twelfth segment. A 135° angle is formed at the connection between the thirteenth and twelfth segments.

[0014] Furthermore, the power supply network also includes a first transmission metal pillar and a second transmission metal pillar, which are used to connect to the front-end device and access radio frequency signals; the first transmission metal pillar penetrates the PP board, the fourth dielectric board, and the second metal ground, and does not contact the second metal ground; the top surface of the first transmission metal pillar is attached to the bottom surface of the first segment of the first gradient metal line; the top surface of the thirteenth segment of the first gradient metal line is attached to the bottom surface of the first metal pillar; the second transmission metal pillar penetrates the fourth dielectric board and the second metal ground, and does not contact the second metal ground; the top surface of the second transmission metal pillar is attached to the bottom surface of the PP board; the portion of the second gradient metal line symmetrical to the first segment of the first gradient metal line is called its first segment, and the portion symmetrical to the thirteenth segment of the first gradient metal line is called its thirteenth segment; the bottom surface of the first segment of the second gradient metal line is attached to the top surface of the second transmission metal pillar, and the top surface of the thirteenth segment of the second gradient metal line is attached to the bottom surface of the third metal pillar.

[0015] Furthermore, the power supply network also includes an electromagnetic shielding structure; the electromagnetic shielding structure includes two electromagnetic shielding units, each of which is formed by five metal pillars evenly spaced along a semicircle, and the five metal pillars vertically penetrate the third dielectric plate, the PP plate, and the fourth dielectric plate, with their top surface attached to the bottom surface of the first metal ground and their bottom surface attached to the top surface of the second metal ground; the two electromagnetic shielding units are the first electromagnetic shielding unit and the second electromagnetic shielding unit; the axis of the semicircle containing the five metal pillars of the first electromagnetic shielding unit coincides with the axis of the first transmission metal pillar; the axis of the semicircle containing the five metal pillars of the second electromagnetic shielding unit coincides with the axis of the second transmission metal pillar. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the dual-circularly polarized phased array antenna for satellite communication according to the present invention;

[0017] Figure 2 This is an exploded view of the antenna element of the dual circularly polarized phased array antenna for satellite communication according to the present invention;

[0018] Figure 3 This is a top view of the antenna element of the dual circularly polarized phased array antenna for satellite communication according to the present invention;

[0019] Figure 4 This is a side view of the antenna element of the dual circularly polarized phased array antenna for satellite communication according to the present invention;

[0020] Figure 5 This is a perspective view of the radiation network of the dual circularly polarized phased array antenna for satellite communication according to the present invention.

[0021] Figure 6 This is a side view of the feed network of the dual circularly polarized phased array antenna for satellite communication according to the present invention;

[0022] Figure 7 This is a perspective view of the feed network for the dual-circularly polarized phased array antenna used in satellite communication according to the present invention.

[0023] Figure 8 This is a schematic diagram of the feed network and radiating patch structure of the dual circularly polarized phased array antenna for satellite communication according to the present invention.

[0024] Figure 9 This is a schematic diagram of the 3dB directional coupler for a dual circularly polarized phased array antenna used in satellite communication according to the present invention;

[0025] Figure 10 This is a schematic diagram of the first gradient metal wire of the dual circularly polarized phased array antenna for satellite communication according to the present invention.

[0026] Figure 11 This is a diagram showing the active reflection coefficient of the antenna element of the dual circularly polarized phased array antenna for satellite communication according to the present invention.

[0027] Figure 12 The axial ratio of the left-hand circular polarization of the antenna element in the dual circularly polarized phased array antenna for satellite communication according to the present invention;

[0028] Figure 13 The axial ratio of the right-hand circular polarization of the antenna element in the dual-circularly polarized phased array antenna for satellite communication according to the present invention;

[0029] Figure 14 The image shows the left-hand circular polarization pattern of the dual circularly polarized phased array antenna for satellite communication according to the present invention, scanned at 10.7 GHz.

[0030] Figure 15 The left-hand circular polarization pattern of the dual circularly polarized phased array antenna for satellite communication according to the present invention is scanned at 12 GHz.

[0031] Figure 16 The image shows the left-hand circular polarization pattern of the dual circularly polarized phased array antenna for satellite communication according to the present invention, scanned at 14.5 GHz.

[0032] Figure 17 The image shows the right-hand circular polarization pattern of the dual circularly polarized phased array antenna for satellite communication according to the present invention, scanned at 10.7 GHz.

[0033] Figure 18 The right-hand circular polarization pattern of the dual circularly polarized phased array antenna for satellite communication according to the present invention is shown in a 12GHz scan.

[0034] Figure 19 The image shows the right-hand circular polarization pattern of the dual circularly polarized phased array antenna for satellite communication according to the present invention, scanned at 14.5 GHz.

[0035] Figure 20 The dual circularly polarized phased array antenna of the present invention, applied to satellite communication, achieves an axial ratio of 60° in left-hand circularly polarized beam scanning at 10.7 GHz;

[0036] Figure 21 The dual circularly polarized phased array antenna of the present invention, applied to satellite communication, achieves an axial ratio of 60° in left-hand circularly polarized beam scanning at 12 GHz.

[0037] Figure 22 The dual circularly polarized phased array antenna of the present invention, applied to satellite communication, achieves an axial ratio of 60° in left-hand circularly polarized beam scanning at 14.5 GHz.

[0038] Figure 23The dual circularly polarized phased array antenna of the present invention, applied to satellite communication, achieves an axial ratio of 60° in right-hand circularly polarized beam scanning at 10.7 GHz;

[0039] Figure 24 The dual circularly polarized phased array antenna of the present invention, applied to satellite communication, achieves an axial ratio of 60° in right-hand circularly polarized beam scanning at 12GHz.

[0040] Figure 25 The dual circularly polarized phased array antenna of the present invention, applied to satellite communication, achieves an axial ratio of 60° in right-hand circularly polarized beam scanning at 14.5 GHz. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0042] Example 1: As Figures 1 to 4As shown, a dual-circularly polarized phased array antenna for satellite communication includes n×m antenna element groups 1 arranged in n rows and m columns without spacing to form an antenna array, where n and m are integers greater than or equal to 2; each antenna element group 1 includes 4 antenna elements 2 arranged in 2 rows and 2 columns without spacing, and when any antenna element 2 is rotated 90°, 180°, and 270° clockwise around a certain axis, it will successively coincide with the other three antenna elements 2; each antenna element 2 includes a feed network 3 and a radiation network 4; the radiation network 4 is used to receive a mixed signal of left-hand circularly polarized radio frequency signals and right-hand circularly polarized radio frequency signals in free space and feeds it into the feed network. 3. Alternatively, it receives orthogonal two-line polarized radio frequency signals fed into the feed network 3, and combines these two-line polarized radio frequency signals into a mixed signal of left-hand circularly polarized radio frequency signal and right-hand circularly polarized radio frequency signal, which is then radiated into free space; the feed network 3 is used to receive radio frequency signals transmitted to it by the front-end equipment, and convert them into orthogonal two-line polarized radio frequency signals fed into the radiation network 4, or convert the mixed signal of left-hand circularly polarized radio frequency signal and right-hand circularly polarized radio frequency signal fed into it by the radiation network 4 into orthogonal two-line polarized radio frequency signals, and then transmit it to the back-end equipment; the radiation network 4 includes a radiation patch structure, which adopts a magnetoelectric dipole structure, and the radiation network 4 also includes a... A metal pillar structure is placed on the lower surface of the radiating patch structure; the radiating patch structure and the metal pillar structure together constitute the current transmission path; the feed network 3 includes a 3dB directional coupler and two г-shaped feed structures, which are orthogonally distributed; the 3dB directional coupler is implemented using a multi-section equiripple symmetrical directional coupling structure capable of achieving step-by-step impedance matching; when the radiating network 4 receives a mixed signal of left-hand circularly polarized RF signal and right-hand circularly polarized RF signal in free space, the current transmission path couples the mixed signal to the two г-shaped feed structures respectively, and each г-shaped feed structure converts the mixed signal at its location into a linearly polarized RF signal, forming two orthogonal linearly polarized RF signals. The signal is fed into a 3dB directional coupler, which combines the two line-polarized RF signals into a single RF signal for transmission to the back-end equipment. When the front-end equipment transmits the RF signal to the feed network 3, the 3dB directional coupler splits the RF signal into two RF signals with a 90° phase difference, and feeds them into two г-type feed structures respectively. The two г-type feed structures convert the RF signals at their respective locations into linearly polarized RF signals, forming two orthogonal line-polarized RF signals coupled to the current transmission path. The two orthogonal line-polarized RF signals are combined on the current transmission path into a mixed signal of left-hand circularly polarized RF signal and right-hand circularly polarized RF signal, which is then radiated into free space.

[0043] In this embodiment, a metal pillar structure is set on the lower surface of the radiating patch structure, so that the metal pillar structure and the radiating patch structure together form a current transmission path. Since the metal pillar structure is below the radiating patch structure, it expands the current transmission path without affecting the upper surface area of ​​the radiating patch structure. Therefore, under the same transmission surface area requirement, the surface area of ​​the radiating patch structure can be reduced, thereby reducing the radiating aperture of antenna element 2, widening the beamwidth during low-frequency signal transmission, significantly improving the gain drop during large-angle scanning, and making the antenna scanning angle larger. The 3dB directional coupler is implemented using a multi-section equi-corrugated symmetrical directional coupling structure, which enables the internal structure of the 3dB directional coupler to achieve step-by-step impedance matching, exhibiting good impedance matching performance. This results in low loss of RF signal during transmission in the 3dB directional coupler, and further ensures that the phase difference of the RF signals fed from the 3dB directional coupler into the two g-type feed structures is stable at 90° throughout the entire operating frequency band, with a reflection coefficient of less than -10dB. This ensures efficient energy transmission and stable circular polarization performance, and expands the antenna bandwidth.

[0044] Example 2: This example is basically the same as Example 1, except that: in this example, as Figure 5As shown, the radiating network 4 also includes a first dielectric substrate 5, a second dielectric substrate 6, and a first metal ground 7. Both the first dielectric substrate 5 and the second dielectric substrate 6 are cuboid structures, with their lengths along the front-to-back direction, their widths along the left-to-right direction, and their thicknesses along the top-to-bottom direction. The first dielectric substrate 5, the second dielectric substrate 6, and the first metal ground 7 are stacked sequentially from top to bottom, and are aligned vertically in the front, back, left, and right directions, respectively. The first dielectric substrate 5 and the second dielectric substrate 6 are both made of Rogers 4350 dielectric. The first metal ground 7 is attached to the lower surface of the second dielectric substrate 6. The radiating patch structure includes a first radiating patch 8, a second radiating patch 9, a third radiating patch 10, and a fourth radiating patch 11. The first radiating patch 8, the second radiating patch 9, the third radiating patch 10, and the fourth radiating patch 11 are all attached to the upper surface of the first dielectric substrate 5. The first radiating patch 8, the second radiating patch 9, the third radiating patch 10, and the fourth radiating patch 11 are all spaced apart horizontally, and the first radiating patch 8, the third radiating patch 10, the second radiating patch 9, and the fourth radiating patch 11 are all spaced apart front-to-back. The central axis of the first dielectric plate 5 along the vertical direction is called the first axis P1. The first axis P1 is located in the gap between the first radiating plate 8, the second radiating plate 9, the third radiating plate 10, and the fourth radiating plate 11. If the first radiating plate 8 rotates about the first axis P1 as the axis of rotation, and rotates clockwise by 90°, 180°, and 270°, it will completely coincide with the second radiating plate 9, the fourth radiating plate 11, and the third radiating plate 10 in sequence. The first radiating plate 8 is formed by opening a first rectangular groove 12 and a second rectangular groove 13 on the first square metal plate 14. The two adjacent sides of the first square metal plate 14 are respectively along the front-back direction and the left-right direction. The right front corner and the left rear corner of the first square metal plate 14 are rounded. The first rectangular groove 12 is close to the right side of the first square metal plate 14, and the second rectangular groove 13 is close to the rear side of the first square metal plate 14. If the second rectangular groove 13 rotates 90° counterclockwise about the center line of the first square metal plate 14 as the axis of rotation, it will completely coincide with the first rectangular groove 12.

[0045] In this embodiment, the metal pillar structure includes a first metal pillar group 15, a second metal pillar group 16, a third metal pillar group 17, and a fourth metal pillar group 18. The first metal pillar group 15 is located below the first radiating sheet 8 and near the left front corner of the first square metal sheet 14. The first metal pillar group 15 includes five metal pillars arranged in an L-shape with equal spacing. All five metal pillars penetrate the first dielectric plate 5 vertically, and their top surfaces are in contact with the lower end surface of the first square metal sheet 14, while their bottom surfaces are flush with the lower surface of the first dielectric plate 5. If the first metal pillar group 15 rotates around the first axis P1 as the pivot, rotating clockwise by 90°, 180°, and 270°, it will successively overlap with the second metal pillar group 16, the fourth metal pillar group 18, and the third metal pillar group 17.

[0046] In this embodiment, the radiation network 4 further includes four forward gain structures, namely a first forward gain structure 19, a second forward gain structure 20, a third forward gain structure 21, and a fourth forward gain structure 22. The first forward gain structure 19 is located below the first square metal sheet 14 and near the right rear corner of the first square metal sheet 14. The first forward gain structure 19 includes three metal pillars arranged in an L-shape with equal spacing. The three metal pillars penetrate the first dielectric plate 5 and the second dielectric plate 6 vertically from top to bottom, and their top surfaces are in contact with the lower end surface of the first square metal sheet 14, and their bottom surfaces are flush with the lower surface of the second dielectric plate 6. The middle metal pillar among the three metal pillars has a through hole that penetrates from top to bottom on the same axis. The through hole is filled with Rogers4350 dielectric. If the first forward gain structure 19 is rotated clockwise by 90°, 180°, and 270° around the first axis P1, it will completely overlap with the second forward gain structure 20, the fourth forward gain structure 22, and the third forward gain structure 21 in sequence.

[0047] In this embodiment, when the feed network 3 feeds in orthogonal two-path polarized radio frequency signals, or receives a mixed signal of left-hand circularly polarized radio frequency signals and right-hand circularly polarized radio frequency signals in free space, changing currents are generated on the surfaces of the current transmission paths (i.e., the surfaces of the first radiating plate 8, the second radiating plate 9, the third radiating plate 10, the fourth radiating plate 11, and each metal pillar in the metal pillar structure). The currents on the surfaces of the first radiating plate 8 and the first metal pillar group 15, the second radiating plate 9 and the second metal pillar group 16, the third radiating plate 10 and the third metal pillar group 17, and the fourth radiating plate 11 and the fourth metal pillar group 18, these four independent surface currents combine and radiate a mixed signal of left-hand circularly polarized radio frequency signals and right-hand circularly polarized radio frequency signals into free space, or the left-hand circularly polarized radio frequency signals are radiated into free space. The mixed polarized RF signal and the right-hand circularly polarized RF signal are coupled to the feed network 3. The first rectangular slot 12 and the second rectangular slot 13 in the first radiating plate 8, as well as the rounded corners, change the surface current distribution, which can effectively extend the impedance bandwidth of the antenna. Similarly, the second radiating plate 9, the third radiating plate 10, and the fourth radiating plate 11 can also effectively extend the impedance bandwidth of the antenna. Since the current transmission path is extended by the metal pillars in the metal pillar structure, it is not necessary to use a radiating patch structure with a large surface area to effectively increase the path distance of the current flow, ensuring the efficient transmission of RF signals. This can effectively reduce the radiating aperture of the antenna element 2, widen the beamwidth when transmitting low-frequency signals, significantly improve the gain drop when scanning at large angles, and make the antenna scanning angle larger. At the same time, by setting four additional forward gain structures, the three metal pillars of each forward gain structure are short-circuited and grounded, which can cancel the backward radiation of the radiating patch structure, thereby obtaining better forward gain and further improving the efficiency of the antenna.

[0048] Example 3: This example is basically the same as Example 2, except that: in this example, as Figures 6 to 8 As shown, the power supply network 3 also includes a third dielectric board 23, a fourth dielectric board 24, and a second metal ground 25; the third dielectric board 23 and the fourth dielectric board 24 are both made of Rogers 4350 dielectric; the third dielectric board 23, the fourth dielectric board 24, and the second metal ground 25 are all cuboid structures, and their lengths are all along the front-to-back direction, their widths are all along the left-to-right direction, and their thicknesses are all along the top-to-bottom direction; the third dielectric board 23, the fourth dielectric board 24, and the second metal ground 25 are arranged sequentially from top to bottom below the first metal ground 7, and the four are aligned vertically and horizontally respectively; the upper surface of the third dielectric board 23 is attached to the lower surface of the first metal ground 7; the second metal ground 25 is attached to the lower surface of the fourth dielectric board 24; there is a gap between the third dielectric board 23 and the fourth dielectric board 24, and a 3dB directional coupler is arranged between the third dielectric board 23 and the fourth dielectric board 24.

[0049] In this embodiment, the two г-shaped feeding structures are a first г-shaped feeding structure and a second г-shaped feeding structure, respectively. The first г-shaped feeding structure includes a first metal wire 26, a first metal pillar 27, and a second metal pillar 28. The first metal wire 26 is attached to the upper surface of the first dielectric substrate 5. The first metal wire 26 extends from the gap between the first radiating plate 8 and the third radiating plate 10 to the gap between the second radiating plate 9 and the fourth radiating plate 11, and is symmetrical about the first axis P1. The first metal wire 26 does not contact the first radiating plate 8, the second radiating plate 9, the third radiating plate 10, or the fourth radiating plate 11. The first metal pillar 27 vertically penetrates the first dielectric substrate 5 and the second dielectric substrate 5. The structure includes a substrate 6, a first metal ground 7, and a third dielectric substrate 23; a first metal pillar 27 is not in contact with the first metal ground 7, and its top surface is in contact with the bottom left end of the first metal line 26, while its bottom end is flush with the lower surface of the third dielectric substrate 23; a second metal pillar 28 vertically penetrates the first dielectric substrate 5, and its top surface is in contact with the bottom right end of the first metal line 26, while its bottom end is flush with the lower surface of the first dielectric substrate 5; the second G-type power supply structure includes a second metal line 29, a third metal line 30, a fourth metal line 31, a third metal pillar 32, a fourth metal pillar 33, a fifth metal pillar 34, and a sixth metal pillar 35, with the second metal line 29, the third metal line 30, and the fourth metal line 31 extending forward and backward; The second metal wire 29 is attached to the upper surface of the first dielectric plate 5 and is located in the gap between the third radiating plate 10 and the fourth radiating plate 11, and behind the first metal wire 26; the fourth metal wire 31 is attached to the upper surface of the first dielectric plate 5 and is located in the gap between the first radiating plate 8 and the second radiating plate 9, and in front of the first metal wire 26; the fourth metal wire 31 and the second metal wire 29 are symmetrical about the first axis P1; the third metal wire 30 is attached to the upper surface of the second dielectric plate 6 and is symmetrical about the first axis P1; the third metal column 32 vertically penetrates the first dielectric plate 5, the second dielectric plate 6, the first metal ground 7, the third dielectric plate 23, and 3d. B. Directional coupler; the third metal post 32 is not in contact with the first metal ground 7, and its top surface is attached to the bottom rear end of the second metal wire 29, and its bottom surface is attached to the upper end surface of the fourth dielectric plate 24; the fourth metal post 33, the fifth metal post 34 and the sixth metal post 35 all penetrate the first dielectric plate 5 vertically; the top surface of the fourth metal post 33 is attached to the bottom front end of the second metal wire 29, and its bottom surface is attached to the top rear end of the third metal wire 30; the top surface of the fifth metal post 34 is attached to the bottom rear end of the fourth metal wire 31, and its bottom surface is attached to the top front end of the third metal wire 30; the top surface of the sixth metal post 35 is attached to the bottom front end of the fourth metal wire 31, and its bottom surface is flush with the lower surface of the first dielectric plate 5.

[0050] In this embodiment, when the 3dB directional coupler feeds two RF signals with a 90° phase difference into two g-type feed structures respectively, the first metal post 27 receives the first RF signal, and the third metal post 32 receives the second RF signal. In the first g-type feed structure, the RF signal is transmitted on the first metal post 27, the second metal post 28, and the first metal line 26. A current is generated on the first metal line 26 along its extension direction, thereby forming a linearly polarized RF signal with a polarization direction along the extension direction of the first metal line 26, and coupled to the current transmission path. In the second g-type feed structure, the RF signal is transmitted on the first metal post 27, the second metal post 28, and the first metal line 26. Transmission occurs on the three metal pillars 32, 33, 34, 35, 29, 30, and 31, causing currents to be generated along their respective extension directions on the second metal line 29, the third metal line 30, and the fourth metal line 31. Since the second metal line 29, the third metal line 30, and the fourth metal line 31 extend in the same direction, a path-polarized radio frequency signal with a polarization direction along their extension directions is generated and coupled to the current transmission path. Thus, the two г-shaped feed structures form two orthogonal path-polarized radio frequency signals coupled to the current transmission path. When the current transmission path couples the mixed signal of the left-hand circularly polarized RF signal and the right-hand circularly polarized RF signal to two г-type feed structures respectively, in the first г-type feed structure, the first metal line 26 receives the mixed signal and induces a current along its extension direction, thereby generating a linearly polarized RF signal with a polarization direction along its extension direction, which is fed into the 3dB directional coupler through the first metal pillar 27; in the second г-type feed structure, the second metal line 29, the third metal line 30, and the fourth metal line 31 receive the mixed signal and induce a current along their own extension direction. Since the second metal line 29, the third metal line 30, and the fourth metal line 31 have the same extension direction, they generate a linearly polarized RF signal with a polarization direction along their extension direction. This linearly polarized RF signal is orthogonal to the linearly polarized RF signal generated in the first г-type feed structure, and is fed into the 3dB directional coupler through the third metal pillar 32; thus, the two г-type feed structures form two orthogonal linearly polarized RF signals fed into the 3dB directional coupler.

[0051] Example 4: This example is basically the same as Example 3, except that: in this example, as Figure 9As shown in the figure, the 3dB directional coupler includes a PP board 36, a first tapered metal wire 37, and a second tapered metal wire 38; the PP board 36 is of a cuboid structure and is arranged between the third dielectric board 23 and the fourth dielectric board 24, and the three are aligned in the front and back, left and right, up and down; the upper surface of the PP board 36 is in contact with the lower surface of the third dielectric board 23, and the lower surface of the PP board 36 is in contact with the upper surface of the fourth dielectric board 24; the third metal column 32 penetrates through the PP board 36 at the same time and is not in contact with both the first tapered metal wire 37 and the second tapered metal wire 38; a first type of "Ji" - shaped groove is provided on the upper end surface of the PP board 36, and the first tapered metal wire 37 is a "Ji" - shaped wire formed by connecting multiple metal wires with offsets, and is arranged in the first type of "Ji" - shaped groove, just filling the first type of "Ji" - shaped groove; a second type of "Ji" - shaped groove is provided on the lower end surface of the PP board 36, and the second tapered metal wire 38 is a "Ji" - shaped wire formed by connecting multiple metal wires with offsets, and is arranged in the second type of "Ji" - shaped groove, just filling the second type of "Ji" - shaped groove; the line connecting the left - rear top corner and the right - front top corner of the upper end surface of the PP board 36 is called the second axis P2; if both the first tapered metal wire 37 and the second tapered metal wire 38 are perpendicularly mapped to the upper end surface of the PP board 36, the second tapered metal wire 38 and the first tapered metal wire 37 will be symmetric about the second axis P2 and have two overlapping areas, and the electrical length of each overlapping area is one - eighth wavelength, where the wavelength refers to the wavelength of the RF signal in free space corresponding to the center frequency of the antenna.

[0052] In this embodiment, when the first RF signal fed into the first tapered metal wire 37 from the first metal column 27 and the second RF signal fed into the second tapered metal wire 38 from the third metal column 32 generate coupling at the two overlapping areas, since the two RF signals are orthogonal and the phase difference is 90°, and the total electrical length of the two overlapping areas is one - quarter wavelength, a phase delay of one - quarter wavelength will be generated when the two RF signals are output, so as to be combined into one RF signal and output to the backend device (such as a receiver); when the frontend device (such as a transmitter) transmits an RF signal to the 3dB directional coupler, the RF signal is coupled up and down at the two overlapping areas into two RF signals, and the total electrical length of the two overlapping areas is one - quarter wavelength, where the wavelength refers to the wavelength of the RF signal in free space corresponding to the center frequency of the antenna, so a phase delay of one - quarter wavelength will be generated when the two RF signals are output, forming two RF signals with a 90° phase difference and being orthogonal, which are fed into two г - type feeding structures.

[0053] Embodiment Five: This embodiment is basically the same as Embodiment Four, the difference is that: in this embodiment, as Figure 10As shown, the first gradient metal line 37 comprises thirteen sequentially connected metal segments, namely, segment 39, segment 40, segment 41, segment 42, segment 43, segment 44, segment 45, segment 46, segment 9, segment 47, segment 48, segment 11, segment 49, segment 12, and segment 51. Segment 39 extends from one end to the left rearward, with the other end offset from one end of segment 40. Segment 40 extends from one end to the right rearward and is perpendicular to segment 39. Segment 41 is offset to the left rearward and connects to the other end of segment 40. Segment 42 is offset to the left rearward and connects to the other end of segment 41. Segment 43 is offset to the left rearward and connects to the other end of segment 42. Segment 6 is offset to the left rearward and connects to the other end of segment 43. Segment 7 is offset to the left rearward and connects to the other end of segment 42. The first segment is offset and connects to the other end of the sixth segment 44. The second segment is offset to the left and connects to the other end of the seventh segment 45. The eighth segment 46 is perpendicular to the seventh segment 45 and extends to the left and rear. The third segment is offset to the other end of the ninth segment 47. The ninth segment 47 is perpendicular to the eighth segment 46 and extends to the left and front. The fourth segment is offset to the other end of the tenth segment 48. The tenth segment 48 is perpendicular to the ninth segment 47 and extends to the left and rear. The eleventh segment 49 is offset to the other end of the tenth segment 48. The eleventh segment 49 is perpendicular to the tenth segment 48 and extends to the left and front. The outer side of the junction of the tenth segment 48 and the eleventh segment 49 forms a triangular chamfer structure. The twelfth segment 50 is offset to the left and connects to the other end of the eleventh segment 49. The thirteenth segment 51 is offset to the other end of the twelfth segment 50. The junction of the thirteenth segment 51 and the twelfth segment 50 forms a 135° angle.

[0054] In this embodiment, the first gradient metal line 37 and the second gradient metal line 38 form an interlaced coupling structure through staggered metal lines, and each staggered metal line is impedance matched step by step, so that the entire 3dB directional coupler has excellent impedance matching effect in the passband, thereby achieving low loss and high isolation.

[0055] Example 6: This example is basically the same as Example 5, except that: In this example, the power supply network further includes a first transmission metal pillar 52 and a second transmission metal pillar 53. The first transmission metal pillar 52 and the second transmission metal pillar 53 are used to connect with the front-end equipment and access radio frequency signals; the first transmission metal pillar 52 penetrates the PP board 36, the fourth dielectric board 24 and the second metal ground 25, and does not contact the second metal ground 25; the top surface of the first transmission metal pillar 52 is attached to the bottom surface of the first segment 39 of the first gradient metal line 37; the top surface of the thirteenth segment 51 of the first gradient metal line 37 is attached to the bottom surface of the first metal pillar 27. The second transmission metal pillar 53 penetrates the fourth dielectric plate 24 and the second metal ground 25, but does not contact the second metal ground 25; the top surface of the second transmission metal pillar 53 is bonded to the bottom surface of the PP plate 36; the part of the second gradient metal line 38 that is symmetrical to the first segment 39 of the first gradient metal line 37 is called its first segment 39, and the part that is symmetrical to the thirteenth segment 51 of the first gradient metal line 37 is called its thirteenth segment 51; the bottom surface of the first segment 39 of the second gradient metal line 38 is bonded to the top surface of the second transmission metal pillar 53, and the top surface of the thirteenth segment 51 of the second gradient metal line 38 is bonded to the bottom surface of the third metal pillar 32.

[0056] In this embodiment, the power supply network also includes an electromagnetic shielding structure; the electromagnetic shielding structure includes two electromagnetic shielding units 54, each electromagnetic shielding unit 54 is formed by five metal pillars distributed at equal intervals along a semicircle, and the five metal pillars penetrate vertically through the third dielectric plate 23, the PP plate 36 and the fourth dielectric plate 24, with their top surface attached to the bottom surface of the first metal ground 7 and their bottom surface attached to the top surface of the second metal ground 25; the two electromagnetic shielding units 54 are the first electromagnetic shielding unit 54 and the second electromagnetic shielding unit 54, respectively; the axis of the semicircle containing the five metal pillars of the first electromagnetic shielding unit 54 coincides with the axis of the first transmission metal pillar 52; the axis of the semicircle containing the five metal pillars of the second electromagnetic shielding unit 54 coincides with the axis of the second transmission metal pillar 53.

[0057] In this embodiment, both electromagnetic shielding units 54 form electromagnetic barriers around the first transmission metal pillar 52 and the second transmission metal pillar 53 by means of semi-circularly distributed metal pillars, which can effectively prevent energy leakage of radio frequency signals when they are transmitted in the first transmission metal pillar 52 and the second transmission metal pillar 53.

[0058] Simulations were performed on the dual-circularly polarized phased array antenna and its antenna elements for satellite communication, with n=2 and m=4. The active reflection coefficient, axial ratio of left-hand circular polarization, and axial ratio of right-hand circular polarization of the antenna elements are as follows: Figures 11 to 13As shown; the left-hand circular polarization pattern under 10.7 GHz frequency scanning, the left-hand circular polarization pattern under 12 GHz frequency scanning, the left-hand circular polarization pattern under 14.5 GHz frequency scanning, the right-hand circular polarization pattern under 10.7 GHz frequency scanning, the right-hand circular polarization pattern under 12 GHz frequency scanning, the right-hand circular polarization pattern under 14.5 GHz frequency scanning, the left-hand circular polarization axial ratio at 10.7 GHz frequency scanning to 60°, the left-hand circular polarization axial ratio at 12 GHz frequency scanning to 60°, the left-hand circular polarization axial ratio at 14.5 GHz frequency scanning to 60°, the right-hand circular polarization axial ratio at 10.7 GHz frequency scanning to 60°, the right-hand circular polarization axial ratio at 12 GHz frequency scanning to 60°, and the left-hand circular polarization axial ratio at 14.5 GHz frequency scanning to 60° are respectively as follows: Figures 14 to 25 As shown.

[0059] analyze Figure 11 It can be seen that the reflection coefficients |S11| and |S22| of port 1 (lower end face of the first transmission metal pillar) and port 2 (lower end face of the second transmission metal pillar) of the antenna element of the present invention are both less than 10dB, and the isolation |S12| between the two ports is greater than 12dB. Therefore, it can be concluded that the antenna element of the present invention has good impedance matching in the 10.7GHz to 14.5GHz frequency band, while its ports 1 and 2 have good isolation. Analysis Figure 12 It can be seen that the axial ratio of the left-hand circular polarization of the antenna element of the present invention is less than 3dB in the passband range, and it has good left-hand circular polarization radiation characteristics in the operating frequency band. Analysis Figure 13 It can be seen that the axial ratio of the right-hand circular polarization of the antenna element of the present invention is less than 4dB in the passband range, and it has good right-hand circular polarization radiation characteristics in the operating frequency band.

[0060] Figure 14 The diagram presents the left-handed circular polarization patterns of this invention at different scanning angles at 10.7 GHz, with the patterns at 0°, 30°, and 60° from the center outwards. Analysis Figure 14 It can be seen that within the ±60° scanning range, the drop in left-hand circular polarization gain is less than 3dB. This indicates that even during large-angle scanning, the left-hand circular polarization radiation pattern of the present invention still maintains good stability and does not exhibit grating lobe effect. Figure 15 The diagram presents the left-handed circular polarization patterns of this invention at different scanning angles at 12 GHz, with the patterns at 0°, 30°, and 60° from the center outwards. Analysis Figure 15It can be seen that within the ±60° scanning range, the drop in left-hand circular polarization gain is less than 3dB. This indicates that even during large-angle scanning, the left-hand circular polarization radiation pattern of the present invention still maintains good stability and does not exhibit grating lobe effect. Figure 16 The invention presents left-handed circular polarization patterns at different scanning angles at a frequency of 14.5 GHz. Figure 16 The image shows the scanning patterns at 0°, 30°, and 60° from the center outwards. Analysis. Figure 16 It can be seen that within the ±60° scanning range, the drop in left-hand circular polarization gain is less than 5dB. This indicates that even during large-angle scanning, the left-hand circular polarization radiograph of the present invention still maintains good stability and does not exhibit grating lobe effect. Figure 17 The right-hand circular polarization pattern of the present invention at different scanning angles at a frequency of 10.7 GHz is presented. Figure 17 The image shows the scanning patterns at 0°, 45°, and 60° from the center outwards. Analysis. Figure 17 It can be seen that within the ±60° scanning range, the drop in right-hand circular polarization gain is less than 3dB. This indicates that even during large-angle scanning, the right-hand circular polarization radiation pattern of the present invention still maintains good stability and does not exhibit grating lobe effect. Figure 18 The right-hand circular polarization patterns of this invention at different scanning angles at 12 GHz are presented, with the scanning patterns from the center outwards at 0°, 30°, and 60°, respectively. Analysis Figure 18 It can be seen that within the ±60° scanning range, the right-hand circular polarization gain drops by less than 3dB, which indicates that even during large-angle scanning, the right-hand circular polarization radiation pattern of the present invention still maintains good stability and no grating lobe effect appears. Figure 19 The right-hand circular polarization patterns of this invention at different scanning angles at 14.5 GHz are presented, with the scanning patterns from the center outwards at 0°, 30°, and 60°, respectively. Analysis Figure 19 It can be seen that within the ±60° scanning range, the drop in right-hand circular polarization gain is less than 5dB. This indicates that even during large-angle scanning, the right-hand circular polarization radiation pattern of the present invention still maintains good stability and does not exhibit grating lobe effect. Figure 20 The axial ratio of the left-handed circular polarization of this invention, scanned to 60° at a frequency of 10.7 GHz, is presented. Analysis Figure 20 It can be seen that the axial ratio of the present invention is less than 3dB within the required scanning angle, which indicates that the present invention has good left-hand circular polarization radiation characteristics within the working frequency band. Figure 21 The axial ratio of the left-handed circular polarization of this invention, scanned to 60° at a frequency of 12 GHz, is presented. Analysis Figure 21 It can be seen that the axial ratio of the present invention is less than 3dB within the required scanning angle, which indicates that the present invention has good left-hand circular polarization radiation characteristics within the working frequency band. Figure 22 The axial ratio of the left-handed circular polarization of this invention, scanned to 60° at a frequency of 14.5 GHz, is presented. Analysis Figure 22 It can be seen that the axial ratio of the present invention is less than 3dB within the required scanning angle, which indicates that the present invention has good left-hand circular polarization radiation characteristics within the working frequency band. Figure 23 The axial ratio of the right-hand circular polarization of this invention, scanned to 60° at a frequency of 10.7 GHz, is presented. Analysis Figure 23 It can be seen that the axial ratio of the present invention is less than 3dB within the required scanning angle, and thus the present invention has good right-hand circular polarization radiation characteristics within the working frequency band. Figure 24 The axial ratio of the right-hand circular polarization of this invention, scanned to 60° at a frequency of 12 GHz, is presented. Analysis Figure 24 It can be seen that the axial ratio of the present invention is less than 3dB within the required scanning angle. Therefore, the present invention has good right-hand circular polarization radiation characteristics within the working frequency band. Figure 25 The axial ratio of the right-hand circular polarization of this invention, scanned to 60° at a frequency of 14.5 GHz, is presented. Analysis Figure 25 It can be seen that the axial ratio of the present invention is less than 3dB within the required scanning angle. Therefore, the present invention has good right-hand circular polarization radiation characteristics within the working frequency band.

[0061] In summary, the dual-circularly polarized phased array antenna for satellite communication of the present invention has a bandwidth of up to 30%, an antenna scanning angle of ±60°, and when scanning to the maximum angle, the low-frequency gain drop is less than 3dB and the high-frequency gain drop is less than 5dB, exhibiting significant high-gain characteristics within the scanning area.

Claims

1. A dual circularly polarized phased array antenna applied to satellite communication, comprising n×m antenna unit groups arranged without interval according to n rows and m columns to form an antenna array, n and m are integers greater than or equal to 2, and × is a multiplication operator; each antenna unit group comprises 4 antenna units arranged without interval according to 2 rows and 2 columns, and any one antenna unit rotates 90°, 180° and 270° clockwise around a rotation axis to coincide with the other three antenna units in turn; each antenna unit comprises a feed network and a radiation network; the radiation network comprises a radiation patch structure, and the radiation patch structure adopts a magnetic-electric dipole structure, characterized in that: The radiation network further includes a metal column structure disposed on the lower surface of the radiation patch structure. The metal columns in the metal column structure are arranged in an L shape and are in contact with a specific area of the lower surface of the radiation patch structure. The radiation patch structure and the metal column structure together form a current transmission path. The feeding network includes a 3dB directional coupler and two Γ-shaped feeding structures, and the two Γ-shaped feeding structures are orthogonally distributed. The 3dB directional coupler is implemented by a multi-section equal-ripple symmetric directional coupling structure capable of achieving step-by-step impedance matching, and includes two types of "Ω"-shaped grooves formed in a PP board. Two "Ω"-shaped gradient metal lines are disposed in the two types of "Ω"-shaped grooves. The two "Ω"-shaped gradient metal lines are each composed of thirteen metal line segments connected in a staggered manner, are orthogonal to each other, and have an overlapping portion with a predetermined electrical length.

2. The dual circularly polarized phased array antenna for satellite communications according to claim 1, characterized in that: The radiation network further includes a first dielectric plate, a second dielectric plate and a first metal ground. The first dielectric plate and the second dielectric plate are both in a cuboid structure, and their lengths are along the front-back direction, widths are along the left-right direction, and thicknesses are along the up-down direction. The first dielectric plate, the second dielectric plate and the first metal ground are stacked from top to bottom, and the three are vertically aligned in the front, back, left and right directions respectively. The first metal ground is attached to the lower surface of the second dielectric plate. The radiation patch structure includes four radiation patches attached to the upper surface of the first dielectric plate, namely a first radiation patch, a second radiation patch, a third radiation patch and a fourth radiation patch. The first radiation patch and the second radiation patch, the third radiation patch and the fourth radiation patch are spaced apart left and right, and the first radiation patch and the third radiation patch, the second radiation patch and the fourth radiation patch are spaced apart front and back. The central axis of the first dielectric plate in the up-down direction is called the first axis. At the gap between the four radiation patches along the first axis; if the first radiation patch rotates clockwise by 90°, 180° and 270° with the first axis as the rotation axis, it will coincide completely with the second radiation patch, the fourth radiation patch and the third radiation patch in sequence. The first radiation patch is realized by forming a first rectangular groove and a second rectangular groove in a first square metal sheet. Two adjacent sides of the first square metal sheet are along the front-back direction and the left-right direction respectively. The right front corner and the left rear corner of the first square metal sheet are rounded corners. The first rectangular groove is close to the right side of the first square metal sheet, and the second rectangular groove is close to the rear side of the first square metal sheet. If the second rectangular groove rotates counterclockwise by 90° with the center line of the first square metal sheet as the rotation axis, it will coincide completely with the first rectangular groove.

3. The dual circularly polarized phased array antenna for satellite communications according to claim 2, characterized in that: The metal column structure comprises a first metal column group, a second metal column group, a third metal column group and a fourth metal column group; the first metal column group is located below the first radiation sheet and close to the left front corner of the first square metal sheet; the first metal column group comprises five metal columns arranged in an L shape at equal intervals, and the five metal columns all vertically penetrate the first dielectric plate from top to bottom, and the top surface thereof is attached to the lower end surface of the first square metal sheet, and the bottom surface is flush with the lower surface of the first dielectric plate; if the first metal column group is rotated around the first axis as the rotation shaft, it will be completely coincided with the second metal column group, the fourth metal column group and the third metal column group in turn by rotating 90°, 180° and 270° clockwise.

4. The dual circularly polarized phased array antenna for satellite communications according to claim 2, characterized in that: The radiation network further comprises four forward gain structures, namely a first forward gain structure, a second forward gain structure, a third forward gain structure and a fourth forward gain structure; the first forward gain structure is arranged below the first square metal sheet and close to the right rear corner of the first square metal sheet; the first forward gain structure comprises three metal columns arranged in an L shape at equal intervals, and the three metal columns all vertically penetrate the first dielectric plate and the second dielectric plate from top to bottom, and the top surface thereof is attached to the lower end surface of the first square metal sheet, and the bottom surface is flush with the lower surface of the second dielectric plate; a through hole penetrating from top to bottom is coaxially arranged in the middle one of the three metal columns, and the through hole is filled with dielectric; if the first forward gain structure is rotated around the first axis as the rotation shaft, it will be completely coincided with the second forward gain structure, the fourth forward gain structure and the third forward gain structure in turn by rotating 90°, 180° and 270° clockwise.

5. The dual circularly polarized phased array antenna for satellite communications according to claim 2, characterized in that: The feed network further comprises a third dielectric plate, a fourth dielectric plate and a second metal ground; the third dielectric plate, the fourth dielectric plate and the second metal ground are all cuboid structures, and the lengths of the three are all along the front-back direction, the widths are all along the left-right direction, and the thicknesses are all along the up-down direction; the third dielectric plate, the fourth dielectric plate and the second metal ground are sequentially arranged below the first metal ground from top to bottom, and the four are vertically aligned in front, back, left and right; the upper surface of the third dielectric plate is attached to the lower surface of the first metal ground; the second metal ground is attached to the lower surface of the fourth dielectric plate; there is a gap between the third dielectric plate and the fourth dielectric plate, and the 3dB directional coupler is arranged between the third dielectric plate and the fourth dielectric plate.

6. The dual circularly polarized phased array antenna for satellite communications according to claim 5, characterized in that: The two g-shaped feed structures are a first g-shaped feed structure and a second g-shaped feed structure; the first g-shaped feed structure comprises a first metal wire, a first metal column and a second metal column attached to the upper surface of the first dielectric plate; the first metal wire extends from between the first radiating sheet and the third radiating sheet to between the second radiating sheet and the fourth radiating sheet and is left-right symmetrical about the first axis, and the first metal wire does not contact the four radiating sheets; the first metal column vertically penetrates the first dielectric plate, the second dielectric plate, the first metal ground and the third dielectric plate from top to bottom; the first metal column does not contact the first metal ground, the top surface thereof contacts the bottom of the left end of the first metal wire, and the bottom end thereof is flush with the lower surface of the third dielectric plate; the second metal column vertically penetrates the first dielectric plate from top to bottom, the top surface thereof contacts the bottom of the right end of the first metal wire, and the bottom end thereof is flush with the lower surface of the first dielectric plate; the second g-shaped feed structure comprises three metal wires, a third metal column, a fourth metal column, a fifth metal column and a sixth metal column; the three metal wires all extend from front to back and are respectively a second metal wire, a third metal wire and a fourth metal wire; The second metal wire is attached to the upper surface of the first dielectric plate and is located between the third radiating sheet and the fourth radiating sheet and behind the first metal wire; The fourth metal wire is attached to the upper surface of the first dielectric plate and is located between the first radiating sheet and the second radiating sheet and in front of the first metal wire; The fourth metal wire and the second metal wire are front-back symmetrical about the first axis; The third metal wire is attached to the upper surface of the second dielectric plate and is front-back symmetrical about the first axis; the third metal column vertically penetrates the first dielectric plate, the second dielectric plate, the first metal ground, the third dielectric plate and the 3dB directional coupler from top to bottom; the third metal column does not contact the first metal ground, the top surface thereof is attached to the bottom of the rear end of the second metal wire, and the bottom surface thereof is attached to the upper end surface of the fourth dielectric plate; the fourth metal column, the fifth metal column and the sixth metal column all vertically penetrate the first dielectric plate from top to bottom; the top surface of the fourth metal column is attached to the bottom of the front end of the second metal wire, and the bottom surface thereof is attached to the top of the rear end of the third metal wire; the top surface of the fifth metal column is attached to the bottom of the rear end of the fourth metal wire, and the bottom surface thereof is attached to the top of the front end of the third metal wire; the top surface of the sixth metal column is attached to the bottom of the front end of the fourth metal wire, and the bottom surface thereof is flush with the lower surface of the first dielectric plate.

7. The dual circularly polarized phased array antenna for satellite communications according to claim 6, characterized in that: The 3dB directional coupler comprises a PP plate, a first tapered metal line and a second tapered metal line; the PP plate is a cuboid structure, arranged between the third dielectric plate and the fourth dielectric plate, and the three are aligned front to back, left to right and top to bottom; the upper surface of the PP plate is attached to the lower surface of the third dielectric plate, and the lower surface of the PP plate is attached to the upper surface of the fourth dielectric plate; the third metal column penetrates the PP plate and does not contact the first tapered metal line and the second tapered metal line; the upper end surface of the PP plate is provided with a first type of 'j' shaped groove, the first tapered metal line is a 'j' shaped line formed by staggered connection of multiple metal lines, arranged in the first type of 'j' shaped groove and filling the first type of 'j' shaped groove; the lower end surface of the PP plate is provided with a second type of 'j' shaped groove, the second tapered metal line is a 'j' shaped line formed by staggered connection of multiple metal lines, arranged in the second type of 'j' shaped groove and filling the second type of 'j' shaped groove; the line connecting the left rear top corner and the right front top corner of the upper end surface of the PP plate is referred to as the second axis; if the first tapered metal line and the second tapered metal line are both perpendicular to the upper end surface of the PP plate, the second tapered metal line and the first tapered metal line are symmetrical about the second axis, and have two overlapping parts, and the electrical length of each overlapping part is one eighth of a wavelength.

8. The dual circularly polarized phased array antenna for satellite communications according to claim 7, characterized in that: The first tapered metal line comprises thirteen metal lines connected in sequence, which are first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, eleventh, twelfth and thirteenth segments; the first segment extends along the left rear from one end, and the other end is staggered connected with one end of the second segment; the second segment extends to the right rear from one end, and is perpendicular to the first segment; the third segment is connected with the other end of the second segment by staggering to the left rear, the fourth segment is connected with the other end of the third segment by staggering to the left rear, the fifth segment is connected with the other end of the fourth segment by staggering to the left rear, the sixth segment is connected with the other end of the fifth segment by staggering to the left rear, the seventh segment is connected with the other end of the sixth segment by staggering to the left rear, the eighth segment is connected with the other end of the seventh segment by staggering to the left rear, and the eighth segment is perpendicular to the seventh segment and extends to the left rear, the ninth segment is connected with the other end of the eighth segment, the ninth segment is perpendicular to the eighth segment and extends to the left front, the tenth segment is connected with the other end of the ninth segment, the tenth segment is perpendicular to the ninth segment and extends to the left rear, the eleventh segment is connected with the other end of the tenth segment, the eleventh segment is perpendicular to the tenth segment and extends to the left front, and a triangular chamfer structure is formed outside the junction of the tenth segment and the eleventh segment; the twelfth segment is connected with the other end of the eleventh segment by staggering to the left rear, and the thirteenth segment is connected with the other end of the twelfth segment, and a 135° angle is formed at the junction of the thirteenth segment and the twelfth segment.

9. The dual circularly polarized phased array antenna for satellite communications of claim 8, wherein: The feeding network further comprises a first transmission metal column and a second transmission metal column, the first transmission metal column and the second transmission metal column are used to connect with the front-end device and access the radio frequency signal; the first transmission metal column penetrates through the PP plate, the fourth dielectric plate and the second metal ground, and does not contact the second metal ground; the top surface of the first transmission metal column is attached to the bottom surface of the first segment of the first gradually-changing metal line; the top surface of the thirteenth segment of the first gradually-changing metal line is attached to the bottom surface of the first metal column; The second transmission metal column penetrates through the fourth dielectric plate and the second metal ground, and does not contact the second metal ground; the top surface of the second transmission metal column is attached to the bottom surface of the PP plate; a symmetric part of the second gradually-changing metal line with the first segment of the first gradually-changing metal line is referred to as the first segment of the second gradually-changing metal line, and a symmetric part of the second gradually-changing metal line with the thirteenth segment of the first gradually-changing metal line is referred to as the thirteenth segment of the second gradually-changing metal line; the bottom surface of the first segment of the second gradually-changing metal line is attached to the top surface of the second transmission metal column, and the top surface of the thirteenth segment of the second gradually-changing metal line is attached to the bottom surface of the third metal column.

10. The dual circularly polarized phased array antenna for satellite communications according to claim 9, characterized in that: The feeding network further comprises an electromagnetic shielding structure; the electromagnetic shielding structure comprises two electromagnetic shielding units, each of which is formed by five metal columns distributed along a semicircle at equal intervals, and the five metal columns vertically penetrate through the third dielectric plate, the PP plate and the fourth dielectric plate from top to bottom, the top surface of the five metal columns is attached to the bottom surface of the first metal ground, and the bottom surface of the five metal columns is attached to the top surface of the second metal ground; the two electromagnetic shielding units are respectively a first electromagnetic shielding unit and a second electromagnetic shielding unit; the axis of the semicircle where the five metal columns of the first electromagnetic shielding unit are located coincides with the axis of the first transmission metal column; the axis of the semicircle where the five metal columns of the second electromagnetic shielding unit are located coincides with the axis of the second transmission metal column.

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