Dual circularly polarized rectangular feed source with fixed phase shift section

Abstract

The invention discloses a dual-circularly-polarized rectangular feed source with a fixed phase-shifting section, which belongs to the technical field of antennas and comprises an orthogonal mode coupler, a circular waveguide dielectric circular polarizer, a square waveguide fixed phase-shifting section and a rectangular horn. The orthogonal mode coupler is connected with one end of the circular waveguide dielectric circular polarizer, the other end of the circular waveguide dielectric circular polarizer is connected with one end of the square waveguide fixed phase shift section, and the other end of the square waveguide fixed phase shift section is connected with the rectangular horn; by adjusting the rotation angle of the dielectric circular polarizer, switching of linear polarization and circular polarization signals can be realized. The dual-circular-polarization feed source realizes a dual-circular-polarization function, realizes differential free design of beam widths of a horizontal plane and a vertical plane, and solves the problem of free design of the beam widths of two planes of the dual-circular-polarization feed source; the problem of low aperture irradiation efficiency of the traditional dual-circularly polarized shaped reflecting surface feed source is solved; the structure is reliable and high in machinability, and the whole structure is easy to achieve.

Description

Technical Field

[0001] The invention relates to the technical field of antennas, in particular to a dual circularly polarized rectangular feed with a fixed phase-shifting segment. Background Art

[0002] As the core component of a reflector antenna, the feed's primary function is to distribute the transmitted signal onto the reflector according to the primary pattern requirements, as well as to receive spatial signals received by the reflector and transmit them to the receiving system. The quality of the feed directly determines the radiation performance of the reflector antenna. Shaped reflector antennas, a key branch of reflector antennas, are widely used in applications requiring specific antenna beam shapes, such as cosecant-squared or inverse cosecant-squared elevation beams. Air traffic control primary radars transmit radio waves from ground-based radar equipment and derive target range and azimuth information based on reflected echoes from aircraft in the air. Multi-beam feed designs can also determine target altitude information. To ensure uniform illumination of targets at the same altitude at different slant ranges, primary radar antennas generally require a cosecant-squared shaped beam in elevation and a pencil beam with low sidelobe characteristics in azimuth.

[0003] Air traffic control primary radars at home and abroad generally use shaped reflector antennas. To achieve dual circular polarization or linear circular polarization switching, the feed source generally uses a circular horn or square horn antenna. Recent patent achievements include patent application publication number CN116154480A, entitled "A Dual Circular Polarization Feed Antenna Based on 3D Printing," which uses a symmetrical groove smooth transition between the orthogonal mode coupler and the circular horn to achieve a dual circular polarization feed design. Another outstanding achievement is patent application publication number CN109119764A, entitled "A Dual Circular Polarization Feed Antenna," which uses a deformed conical horn as the feed source. The benefit of this invention is that it improves the isolation of the feed antenna and reduces the antenna sidelobes.

[0004] In summary, the existing research results of dual circular polarization feeds are all based on circular horns or square horns, so that the illumination levels in the horizontal and vertical apertures are consistent. However, the horizontal and vertical apertures of the shaped reflector in reality are not consistent. Using a feed with the same beam width to illuminate different apertures in the horizontal and vertical planes will lead to a decrease in the overall aperture efficiency of the antenna, thereby resulting in a decrease in gain and differences in sidelobe levels. Therefore, there is an urgent need for a new feed system that can meet the requirements of dual circular polarization or linear circular polarization conversion and realize the free design of beam width in the horizontal and vertical planes. Summary of the Invention

[0005] In view of the above problems existing in the prior art, the object of the present invention is to provide a dual circularly polarized rectangular feed with a fixed phase shift segment to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A dual circular polarization rectangular feed with a fixed phase shift section, comprising an orthogonal mode coupler, a circular waveguide dielectric circular polarizer, a square waveguide fixed phase shift section and a rectangular horn;

[0008] The orthogonal mode coupler is connected to one end of a circular waveguide dielectric circular polarizer, the other end of the circular waveguide dielectric circular polarizer is connected to one end of a square waveguide fixed phase shift section, and the other end of the square waveguide fixed phase shift section is connected to a rectangular horn;

[0009] One end of the orthogonal mode coupler away from the connection with the circular waveguide medium circular polarizer is a vertical polarization input port, and a horizontal polarization input port is provided on a side wall of the orthogonal mode coupler;

[0010] The inner wall of the horizontal polarization input port is provided with three-level conversion steps, which are arranged close to the vertical polarization input port; a metal diaphragm is provided in the middle of the inner wall of the horizontal polarization input port;

[0011] A first epoxy resin dielectric plate is provided in the middle of the inner wall of the circular waveguide dielectric circular polarizer;

[0012] The bottom circular waveguide coil of the circular waveguide dielectric circular polarizer is connected to the square-to-circular conversion coil of the square waveguide fixed phase shift section;

[0013] A second epoxy resin dielectric plate is provided in the middle of the inner wall of the square waveguide fixed phase shift section; the square waveguide fixed phase shift section is used to compensate for the phase difference between two orthogonally polarized signals when they pass through the rectangular horn and reach the aperture.

[0014] A step change section is provided on the inner wall of the rectangular horn opening;

[0015] The inner wall of the rectangular speaker is provided with tuning screws, and there are two groups of tuning screws.

[0016] As a further solution of the present invention: the long side and the wide side of the rectangular speaker are of different lengths.

[0017] As a further solution of the present invention: the tuning screw is the inner wall of the wide side wall of the rectangular speaker.

[0018] As a further solution of the present invention: the structure of the second epoxy resin dielectric plate is a thin-thick-thin structure, a step-changing structure or a gradual structure.

[0019] As a further solution of the present invention: the second epoxy resin dielectric plate adopts the same dielectric constant as the first epoxy resin dielectric plate.

[0020] As a further solution of the present invention: the included angle between the first epoxy resin dielectric plate and the wide side of the vertical polarization input port is 45° clockwise.

[0021] As a further solution of the present invention: the vertical polarization input port and the horizontal polarization input port of the orthogonal mode coupler are both configured using a BJ32 standard waveguide with an aperture size of 72.14×34.04 mm.

[0022] As a further solution of the present invention: the wall thickness of the metal diaphragm is 1 mm, and the diameter of the bottom circular waveguide ring is 78 mm.

[0023] As a further solution of the present invention: the dielectric constant of the first epoxy resin medium is 4.5.

[0024] As a further solution of the present invention: the diameter of the tuning screw is 6 mm.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention can also realize switching between linear polarization and circular polarization signals by adjusting the rotation angle of the dielectric circular polarizer.

[0027] The present invention provides a dual circularly polarized rectangular feed with a fixed phase shift segment. This feed not only realizes the dual circular polarization function, but also enables the differentiated free design of the horizontal and vertical beam widths, thus solving the problem of freely designing the beam widths of the two planes of the dual circularly polarized feed.

[0028] 2. The dual circularly polarized rectangular feed with a fixed phase shift segment of the present invention solves the problem of low aperture illumination efficiency of traditional dual circularly polarized shaped reflector feeds;

[0029] 3. A dual circular polarization rectangular feed with a fixed phase shift segment of the present invention can not only realize the dual circular polarization function, but also realize linear circular polarization switching by rotating the epoxy resin in the circular waveguide dielectric polarizer between 0° and 45°;

[0030] 4. The present invention provides a dual circularly polarized rectangular feed with a fixed phase shift segment. The feed adopts a rectangular horn with tuning screws and step transformation. The structure is reliable and has strong machinability. The overall structure is easy to implement. It has very broad application prospects in practical engineering, especially in shaped reflective surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a schematic structural diagram of a dual circularly polarized rectangular feed with a fixed phase-shifting segment disclosed in an embodiment.

[0032] Figure 2 The present invention is a schematic structural diagram of a mid-orthogonal mode coupler of a dual circularly polarized rectangular feed with a fixed phase-shifting segment disclosed in an embodiment.

[0033] Figure 3The present invention is a schematic structural diagram of a medium circular waveguide dielectric circular polarizer with a dual circular polarization rectangular feed and a fixed phase shift segment disclosed in an embodiment.

[0034] Figure 4 The present invention is a schematic diagram of the structure of a square waveguide fixed phase-shift segment in a dual circularly polarized rectangular feed with a fixed phase-shift segment disclosed in an embodiment.

[0035] Figure 5 The present invention is a structural schematic diagram of a rectangular horn in a dual circularly polarized rectangular feed with a fixed phase shift segment disclosed in an embodiment.

[0036] Figure 6 The horizontal and vertical plane directional diagrams of the embodiment of the present invention when working with right-hand circular polarization;

[0037] Figure 7 The horizontal and vertical plane directional diagrams of the embodiment of the present invention when working with left-hand circular polarization;

[0038] Figure 8 This is a simulation diagram of the horizontal and vertical axis ratios of an embodiment of the present invention;

[0039] In the figure: 1. Orthogonal mode coupler; 11. Vertical polarization input port; 12. Horizontal polarization input port; 13. Metal diaphragm; 14. Three-stage transformation step; 2. Circular waveguide dielectric circular polarizer; 21. First epoxy resin dielectric plate; 22. Bottom circular waveguide ring; 3. Square waveguide fixed phase shift section; 31. Square-to-circular transformation ring; 32. Second epoxy resin dielectric plate; 4. Rectangular horn; 41. Tuning screw; 42. Step transformation section. DETAILED DESCRIPTION

[0040] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort shall fall within the scope of protection of the present invention.

[0041] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "provided with," "connected," and "connected" should be understood in a broad sense; for example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections via an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific contexts.

[0042] See also Figure 1-5, a dual circular polarization rectangular feed with a fixed phase shift segment, comprising an orthogonal mode coupler 1, a circular waveguide dielectric circular polarizer 2, a square waveguide fixed phase shift segment 3 and a rectangular horn 4;

[0043] The orthogonal mode coupler 1 is connected to one end of a circular waveguide dielectric circular polarizer 2, the other end of the circular waveguide dielectric circular polarizer 2 is connected to one end of a square waveguide fixed phase shift section 3, and the other end of the square waveguide fixed phase shift section 3 is connected to a rectangular horn 4;

[0044] One end of the orthogonal mode coupler 1 away from the connection with the circular waveguide dielectric circular polarizer 2 is a vertical polarization input port 11, and a horizontal polarization input port 12 is provided on the side wall of the orthogonal mode coupler 1;

[0045] A three-stage conversion step 14 is provided on the inner wall of the horizontal polarization input port 12, and the three-stage conversion step 14 is provided close to the vertical polarization input port 11; a metal diaphragm 13 is provided in the middle of the inner wall of the horizontal polarization input port 12;

[0046] A first epoxy resin dielectric plate 21 is provided in the middle of the inner wall of the circular waveguide dielectric circular polarizer 2;

[0047] The bottom circular waveguide coil 22 of the circular waveguide dielectric circular polarizer 2 is connected to the square-to-circular conversion coil 31 of the square waveguide fixed phase shift section 3;

[0048] A second epoxy resin dielectric plate 32 is provided in the middle of the inner wall of the square waveguide fixed phase shift section 3;

[0049] The inner wall of the opening of the rectangular speaker 4 is provided with a step change section 42;

[0050] The inner wall of the rectangular speaker 4 is provided with tuning screws 41, and there are two sets of tuning screws 41;

[0051] The RF signal is input from the vertical polarization input port 11 or the horizontal polarization input port 12 of the orthogonal mode coupler 1, reaches the bottom of the square waveguide fixed phase shift section 3 through the circular waveguide dielectric circular polarizer 2, is transmitted through the square waveguide fixed phase shift section 3 to reach the rectangular horn 4, and then is electromagnetically radiated into space through the rectangular horn 4.

[0052] The long side and the wide side of the rectangular speaker 4 are of different lengths. The tuning screws 41 are arranged on the inner wall of the wide side of the rectangular speaker 4. The tuning screws 41 are symmetrically arranged in the vertical aperture direction of the rectangular speaker 4, including but not limited to;

[0053] The square waveguide fixed phase shift section 3 includes but is not limited to a square waveguide, and may also be a circular waveguide;

[0054] The second epoxy resin dielectric plate 32 has a thin-thick-thin structure, a step-change structure, or a gradual change structure.

[0055] The circular waveguide dielectric circular polarizer 2 includes but is not limited to a dielectric circular polarizer, and may also be other types of circular polarizers such as a metal diaphragm type;

[0056] The vertical polarization input port 11 of the orthogonal mode coupler 1 undergoes, including but not limited to, a three-step step transformation 14 and a metal diaphragm 13, so that the signal is matched and transmitted upward. The horizontal polarization input port 12 is isolated from the vertical polarization input port 11 due to the arrangement of the metal diaphragm 13, so that the signal is matched and transmitted upward.

[0057] The embodiments of the present invention not only achieve dual circular polarization characteristics with a good axial ratio within a wide angle range of ±50° in the horizontal and vertical planes, but also substantially achieve a 9dB reduction in the horizontal illumination level within the ±50° wide angle range and a 15dB reduction in the vertical illumination level as required. Similarly, the structural form of the present invention can easily realize various differentiated illumination level designs for the horizontal and vertical planes.

[0058] In the present invention, the vertically polarized radio frequency signal is input from the rectangular waveguide port 11, as shown in FIG. Figure 1 and Figure 3 As shown, after passing through the step change 14 and the metal diaphragm 13, the signal is matched and transmitted toward the circular waveguide dielectric circular polarizer 2, reaching the bottom circular waveguide 22 of the circular waveguide dielectric circular polarizer 2, and then passing through the first epoxy resin dielectric plate 21 to the square waveguide fixed phase shift section 3. The angle between the first epoxy resin dielectric plate 21 and the wide side of the vertical polarization input port 11 is 45° clockwise. After passing through the circular waveguide dielectric circular polarizer 2, the vertically polarized RF signal is decomposed into two orthogonally polarized signals with a phase difference of 90°, thereby achieving a right-handed circularly polarized RF signal. Professionals familiar with the principles of circular polarizers can master this design method and will not be described in detail here. The function of the square waveguide fixed phase shift section 3 is to compensate for the phase difference between the two orthogonally polarized signals when they pass through the rectangular speaker 4 and reach the aperture, thereby ensuring that the right-handed circularly polarized signal formed by the vertically polarized RF signal after passing through the circular waveguide dielectric circular polarizer 2 remains right-handed circularly polarized when it reaches the aperture of the rectangular speaker 4. Assume that two orthogonally polarized signals with equal amplitudes and a phase difference of 90° become two orthogonally polarized signals with equal amplitudes and a phase difference of (90-T)° after passing through the square waveguide fixed phase shift section 3. When they pass through the rectangular horn 4 and reach the aperture, they become two orthogonally polarized signals with equal amplitudes and a phase difference of (90-T+T)°=90°, thus forming circular polarization. Here, T° is the fixed phase shift degree.

[0059] Similarly, the horizontally polarized RF signal is input from the rectangular waveguide port 12, and after passing through the circular waveguide dielectric polarizer 2, it is realized as a left-handed circularly polarized RF signal. For the same reason, it is still left-handed circularly polarized when it reaches the rectangular horn 4.

[0060] To sum up, the vertically polarized RF signal is input from the rectangular waveguide port 11, passes through the circular waveguide dielectric circular polarizer 2 and the square waveguide fixed phase shift segment 3, and the rectangular horn 4 with tuning screws and step transformation, and realizes the right-handed circularly polarized signal with differentiated illumination levels in the horizontal and vertical planes, and irradiates the shaped reflecting surface; the horizontally polarized RF signal is input from the rectangular waveguide port 12, passes through the circular waveguide dielectric circular polarizer 2 and the square waveguide fixed phase shift segment 3, and the rectangular horn 4 with tuning screws and step transformation, and realizes the left-handed circularly polarized signal with differentiated illumination levels in the horizontal and vertical planes, and irradiates the shaped reflecting surface, thereby improving the aperture efficiency of the shaped reflecting surface and obtaining excellent antenna working performance.

[0061] This embodiment operates in the 2.7 GHz to 2.9 GHz frequency band. Both the vertical polarization input port 11 and the horizontal polarization input port 12 of the orthogonal mode coupler 1 utilize standard BJ32 waveguides with aperture dimensions of 72.14 × 34.04 mm. To achieve a matching transition from the rectangular waveguide of the vertical polarization input port 11 to a circular waveguide, a three-step step transition 14 is employed. To achieve port isolation between the vertical polarization port 11 and the horizontal polarization port 12, a metal diaphragm 13 with a wall thickness of 1 mm is provided. The bottom circular waveguide ring 22 has an aperture of 78 mm, and the epoxy resin dielectric 21 has a dielectric constant of approximately 4.5. To achieve good matching and reduce unnecessary reflections, a "thin-thick-thin" structure is employed, with lengths of 35.6 mm, 83.6 mm, and 35.6 mm, respectively, and dielectric thicknesses of 1.85 mm, 3.4 mm, and 1.85 mm, respectively. The square in the square-to-circle conversion ring 31 measures 66mm x 66mm. The second epoxy resin dielectric plate 32 is used to adjust the phases of the two orthogonal polarizations to form a fixed phase difference. This embodiment is designed to form a fixed phase difference of 82° to compensate for the phase difference between the two orthogonal polarizations of the rectangular speaker 4 on the transmission path. The second epoxy resin dielectric plate 32 uses the same dielectric constant as the first epoxy resin dielectric plate 21, with lengths of 55mm + 105mm + 55mm and dielectric thicknesses of 1.3mm + 1.7mm + 1.3mm. The rectangular speaker 4 consists of three variable apertures 42, with horizontal and vertical apertures of 1100mm and 200mm, respectively. To achieve further matching within the bandwidth, symmetrical tuning screws 41 with a diameter of 6mm are added in the vertical aperture direction.

[0062] According to the results of the overall index decomposition, the requirement of this embodiment is that the feed source can achieve a 9dB reduction in the horizontal plane illumination level and a 15dB reduction in the vertical plane illumination level within the ±50° beam width of the two planes. Figure 6 , are the horizontal and vertical plane radiation patterns of this embodiment when working with right-hand circular polarization. Within the range of ±50°, the illumination level of the horizontal plane decreases by 9.2dB, and the illumination level of the vertical plane decreases by 14.6dB; see Figure 7, are the horizontal and vertical plane radiation patterns of this embodiment when working with left-hand circular polarization. Within the range of ±50°, the illumination level of the horizontal plane drops by 9.3dB, and the illumination level of the vertical plane drops by 14.8dB, which are well matched with the ideal design requirements. Figure 8 , which is a simulation diagram of the axial ratio of the horizontal and vertical planes of this embodiment. Within the range of ±50°, the axial ratio is better than 3dB.

[0063] The present invention also enables switching between linearly and circularly polarized signals by adjusting the rotation angle of the dielectric circular polarizer. The present invention also provides a dual circularly polarized rectangular feed with a fixed phase-shift segment. This feed not only achieves dual circular polarization functionality but also allows for the differentiated and free design of horizontal and vertical beamwidths, resolving the challenge of freely designing the beamwidths of both planes in a dual circularly polarized feed.

[0064] The dual circularly polarized rectangular feed with a fixed phase shift segment of the present invention solves the problem of low aperture illumination efficiency of traditional dual circularly polarized shaped reflector feeds.

[0065] The present invention provides a dual circular polarization rectangular feed with a fixed phase shift segment. The feed can not only realize the dual circular polarization function, but also realize linear circular polarization switching by rotating the epoxy resin 21 in the circular waveguide dielectric polarizer 2 between 0° and 45°.

[0066] The present invention discloses a dual circularly polarized rectangular feed with a fixed phase shift segment. The feed adopts a rectangular horn with a tuning screw and a step change. The structure is reliable and workable, and the overall structure is easy to realize. It has very broad application prospects in practical engineering, especially in shaped reflective surfaces.

[0067] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-limiting. The scope of the invention is defined by the appended claims, not the foregoing description, and it is intended that all variations within the meaning and range of equivalents of the claims be encompassed within the present invention, and any reference signs in the claims should not be construed as limiting the claim to which they relate.

[0068] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A dual circular polarization rectangular feed with a fixed phase shift segment, characterized in that: It comprises an orthogonal mode coupler (1), a circular waveguide dielectric circular polarizer (2), a square waveguide fixed phase shift section (3) and a rectangular horn (4); The orthogonal mode coupler (1) is connected to one end of a circular waveguide dielectric circular polarizer (2), the other end of the circular waveguide dielectric circular polarizer (2) is connected to one end of a square waveguide fixed phase shift section (3), and the other end of the square waveguide fixed phase shift section (3) is connected to a rectangular horn (4); One end of the orthogonal mode coupler (1) away from the connection with the circular waveguide medium circular polarizer (2) is a vertical polarization input port (11), and a horizontal polarization input port (12) is provided on a side wall of the orthogonal mode coupler (1); The inner wall of the horizontal polarization input port (12) is provided with three-level conversion steps (14), and the three-level conversion steps (14) are arranged close to the vertical polarization input port (11); a metal diaphragm (13) is provided in the middle position of the inner wall of the horizontal polarization input port (12); A first epoxy resin dielectric plate (21) is provided at the middle position of the inner wall of the circular waveguide dielectric circular polarizer (2); The bottom circular waveguide coil (22) of the circular waveguide dielectric circular polarizer (2) is connected to the square-to-circular conversion coil (31) of the square waveguide fixed phase shift section (3); A second epoxy resin dielectric plate (32) is provided at the middle position of the inner wall of the square waveguide fixed phase shift section (3); the square waveguide fixed phase shift section (3) is used to compensate for the phase difference between two orthogonally polarized signals when they pass through the rectangular horn (4) and reach the aperture. The inner wall of the opening of the rectangular speaker (4) is provided with a step-changing section (42); The inner wall of the rectangular speaker (4) is provided with tuning screws (41), and the tuning screws (41) are provided with two groups.

2. A dual circularly polarized rectangular feed with a fixed phase shift segment according to claim 1, characterized in that: The long side and the wide side of the rectangular speaker (4) have different lengths.

3. The dual circularly polarized rectangular feed with a fixed phase shift segment according to claim 2, characterized in that: The tuning screw (41) is an inner wall of the wide side wall of the rectangular speaker (4).

4. The dual circularly polarized rectangular feed with a fixed phase shift segment according to claim 2, characterized in that: The structure of the second epoxy resin dielectric plate (32) is a thin-thick-thin structure, a step-changing structure or a gradual change structure.

5. The dual circularly polarized rectangular feed with a fixed phase shift segment according to claim 4, characterized in that: The second epoxy resin dielectric plate (32) adopts the same dielectric constant as the first epoxy resin dielectric plate (21).

6. The dual circularly polarized rectangular feed with a fixed phase shift segment according to claim 5, characterized in that: The included angle between the first epoxy resin dielectric plate (21) and the wide side of the vertical polarization input port (11) is 45° in the clockwise direction.

7. The dual circularly polarized rectangular feed with a fixed phase shift segment according to claim 6, characterized in that: The vertical polarization input port (11) and the horizontal polarization input port (12) of the orthogonal mode coupler (1) are both configured using a BJ32 standard waveguide, with an aperture size of 72.14×34.04 mm.

8. The dual circularly polarized rectangular feed with a fixed phase shift segment according to claim 7, characterized in that: The wall thickness of the metal diaphragm (13) is 1 mm, and the diameter of the bottom circular waveguide ring (22) is 78 mm.

9. The dual circularly polarized rectangular feed with a fixed phase shift segment according to claim 5, characterized in that: The dielectric constant of the first epoxy resin dielectric plate (21) is 4.

5.

10. The dual circularly polarized rectangular feed with a fixed phase shift segment according to claim 1, characterized in that: The tuning screw (41) has a diameter of 6 mm.

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