Waveguide coaxial coupling circularly polarized antenna

Abstract

The invention discloses a waveguide coaxial coupling circularly polarized antenna, and relates to the technical field of antennas, the waveguide coaxial coupling circularly polarized antenna comprises a ridge waveguide, a PCB coupling structure and a PCB radiation structure, the PCB coupling structure is fixedly arranged above the ridge waveguide, the PCB radiation structure is arranged above the PCB coupling structure, and the PCB coupling structure and the PCB radiation structure are isolated through an isolation wall; an upper coupling cavity is formed in the upper surface of the ridge waveguide, a lower coupling cavity is formed in the position, close to the upper portion of a ridge waveguide cavity, in the ridge waveguide, the upper coupling cavity and the lower coupling cavity are communicated through a gap, the lower portion of the lower coupling cavity is communicated with the ridge waveguide cavity through a through hole, and a coaxial probe is arranged in the through hole, communicated with the ridge waveguide cavity, of the lower coupling cavity. According to the waveguide coaxial coupling circularly polarized antenna provided by the invention, a PCB coupling + PCB radiation form is adopted, the size of the antenna unit is reduced, compact layout is realized, and the whole antenna unit is good in performance and convenient for networking.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to a waveguide coaxial coupled circularly polarized antenna. Background Art

[0002] In satellite communication systems, circularly polarized antennas with compactness, high efficiency, large axial ratio beamwidth, and ultra-wideband characteristics have been widely used. Among them, the two indicators of large axial ratio beamwidth and ultra-wideband are in strong demand in the field of broadband circularly polarized phased array antennas. This is because the large axial ratio beamwidth can ensure that the circularly polarized phased array antenna still maintains good axial ratio characteristics when performing large-angle scanning; and the ultra-wideband circularly polarized antenna with a single feed point has a positive significance for reducing the complexity of the antenna system. In addition, high-efficiency antenna units are always of great significance in array antennas.

[0003] At present, common circularly polarized antennas include pure metal circularly polarized antennas, dual-feed point circularly polarized antennas, offset-fed single-feed point circularly polarized antennas, and offset-fed single-feed point circularly polarized antennas guided to the center feed through multi-layer transmission lines.

[0004] Pure metal circularly polarized antennas use air-coupled pure metal circularly polarized antennas, which have the advantages of relatively wide bandwidth and high radiation efficiency. However, existing pure metal circularly polarized antennas have defects such as large antenna unit size, difficulty in integration, and disadvantageous for small-pitch array formation.

[0005] The dual-feed circularly polarized antenna has the advantages of large axial ratio beamwidth and ultra-wideband. However, the dual-feed circularly polarized antenna is not conducive to using a rotation layout to further increase the axial ratio beamwidth, and its own dual-feed network is relatively complex, which is not conducive to reducing costs.

[0006] The offset-fed single-feed-point circularly polarized antenna has the advantages of simple structure and easy integration; however, the axial ratio beam width and relative working bandwidth of the single feed point of the offset-fed single-feed-point circularly polarized antenna are narrow, and the antenna indicators are poor.

[0007] Although the offset-fed single feeding point is guided to the center feeding through a multi-layer transmission line, it is easy to make polarization rotation layout and improve the axial ratio beam width. However, it requires increasing the number of network layers, which is not conducive to reducing costs and affects the antenna radiation efficiency.

[0008] In order to solve the defects of circularly polarized antennas, the prior art discloses a low-profile, wide-bandwidth, and wide-angle scanning circularly polarized array antenna design, and proposes a single-feed-point rotating dipole circularly polarized antenna, placing the coaxial feeding point at the center of the antenna, which reduces the process difficulty after the antenna is rotated. However, the coaxial probe needs to be welded to the top-layer radiation sheet, which is not suitable for high-frequency antennas due to the large welding differences; in addition, the exposed probe and solder point on the top layer are prone to radiation, affecting the antenna performance.

[0009] The patent with application number 202410270811.7 and patent name "A single-layer dual-frequency circularly polarized metasurface antenna for maritime communications" discloses a single-layer dual-frequency circularly polarized metasurface antenna, including a dielectric substrate, a metasurface array located on the upper surface of the dielectric substrate, and a coplanar waveguide feeding structure located on the lower surface of the dielectric substrate; the metasurface array is composed of n×n square patches, each square patch is a truncated square patch, and a vertical slit is cut at the center of each square patch; the size of the square patch located in the first row of the metasurface array is the same as the size of the square patch located in the nth row of the metasurface array, and both are smaller than the size of the square patches located in other rows of the metasurface array. Although this scheme realizes the circularly polarized antenna form with center-coupled feeding. However, the antenna is directly composed of the array surface, which is difficult to be applied to phased array antenna arrays with limited spacing. Summary of the invention

[0010] To this end, the present application provides a waveguide coaxial coupled circularly polarized antenna to solve the problems of large antenna unit size, high cost and poor performance in the prior art.

[0011] In order to achieve the above objectives, this application provides the following technical solutions:

[0012] A waveguide coaxial coupled circularly polarized antenna comprises a ridge waveguide, a PCB coupling structure and a PCB radiation structure, wherein the PCB coupling structure is fixedly arranged above the ridge waveguide, the PCB radiation structure is arranged above the PCB coupling structure, and the PCB coupling structure and the PCB radiation structure are isolated by an isolation wall; an upper coupling cavity is provided on the upper surface of the ridge waveguide, the PCB coupling structure is fixedly arranged above the upper coupling cavity, a lower coupling cavity is provided inside the ridge waveguide at an upper position close to the ridge waveguide cavity, the upper coupling cavity and the lower coupling cavity are connected through a gap, the lower part of the lower coupling cavity is connected to the ridge waveguide cavity through a through hole, a coaxial probe is arranged in the through hole through which the lower coupling cavity is connected to the ridge waveguide cavity, one end of the coaxial probe extends to the lower coupling cavity and is fixedly connected to the top of the lower coupling cavity, and the other end is located in the ridge waveguide cavity.

[0013] Preferably, the PCB radiation structure comprises an upper PCB board and an upper radiation sheet, and the upper radiation sheet is fixedly arranged below the upper PCB board and faces the PCB coupling structure.

[0014] Preferably, the PCB coupling structure comprises a lower PCB board and a lower coupling plate, and the lower coupling plate is fixedly arranged above the lower PCB board and faces the upper radiation plate.

[0015] Preferably, the upper radiation plate and the lower coupling plate are rotatable and their sizes can be adjusted.

[0016] Preferably, the gap is a U-shaped gap.

[0017] Preferably, the U-shaped gap can adjust the coupling frequency and the axial ratio.

[0018] Preferably, the coaxial probe is in the shape of a screw.

[0019] Preferably, one end of the coaxial probe with a thread passes through the top of the lower coupling cavity and is fixedly arranged at the bottom of the upper coupling cavity, and the other end is located in the ridge waveguide cavity.

[0020] Preferably, one threaded end of the coaxial probe passes through the top of the lower coupling cavity and is fixed at the bottom of the upper coupling cavity, and the other end passes through the bottom of the ridge waveguide cavity and is fixed at the bottom of the ridge waveguide.

[0021] Preferably, the ridge waveguide is a metal ridge waveguide.

[0022] Compared with the prior art, this application has at least the following beneficial effects:

[0023] 1. The present application provides a waveguide coaxial coupled circularly polarized antenna, including a ridge waveguide, a PCB coupling structure and a PCB radiation structure, wherein the PCB coupling structure is fixedly arranged above the ridge waveguide, the PCB radiation structure is arranged above the PCB coupling structure, and the PCB coupling structure and the PCB radiation structure are isolated by an isolation wall; an upper coupling cavity is provided on the upper surface of the ridge waveguide, the PCB coupling structure is fixedly arranged above the upper coupling cavity, a lower coupling cavity is provided inside the ridge waveguide at an upper position close to the ridge waveguide cavity, the upper coupling cavity and the lower coupling cavity are connected through a gap, the lower part of the lower coupling cavity is connected to the ridge waveguide cavity through a through hole, a coaxial probe is arranged in the through hole connecting the lower coupling cavity and the ridge waveguide cavity, one end of the coaxial probe extends to the lower coupling cavity and is fixedly connected to the top of the lower coupling cavity, and the other end is located in the ridge waveguide cavity. The waveguide coaxial coupled circularly polarized antenna provided in the present application adopts the form of PCB coupling + PCB radiation, which is conducive to reducing the size of the antenna unit and realizing a compact layout, and the entire antenna unit has good performance and is easy to network.

[0024] 2. PCB coupling and PCB radiation are independent and can rotate appropriately, thereby improving the axial ratio performance of the antenna unit.

[0025] 3. Using a U-shaped gap can reduce the air coupling size.

[0026] 4. The screw probe form can make the structure more compact and reduce signal leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more intuitively illustrate the prior art and the present application, exemplary drawings are given below. It should be understood that the specific shapes and structures shown in the drawings should not generally be regarded as limiting conditions for implementing the present application; for example, those skilled in the art are capable of easily making conventional adjustments or further optimizations to the addition / reduction / attribution division, specific shapes, positional relationships, connection methods, dimensional ratios, etc. of certain units (components) based on the technical concepts and exemplary drawings disclosed in the present application.

[0028] Figure 1 A schematic diagram (cross-sectional view) of the overall structure of a waveguide coaxial coupled circularly polarized antenna provided in this application;

[0029] Figure 2 A schematic diagram (cross-sectional view) of the lower coupling cavity and through-hole structure of a waveguide coaxial coupled circularly polarized antenna provided in the present application;

[0030] Figure 3 A schematic diagram (cross-sectional view) of a lower coupling cavity structure and a slot structure of a waveguide coaxially coupled circularly polarized antenna provided in the present application;

[0031] Figure 4 A schematic diagram (top view) of a U-shaped slot of a waveguide coaxial coupled circularly polarized antenna provided in the present application;

[0032] Figure 5 A schematic diagram (cross-sectional view) of a PCB coupling structure and a PCB radiation structure of a waveguide coaxial coupled circularly polarized antenna provided in this application;

[0033] Figure 6 A rotational schematic diagram (top view) of a lower coupling plate and an upper radiating plate of a waveguide coaxially coupled circularly polarized antenna provided in the present application;

[0034] Figure 7 A top view rotation diagram (top view) of a waveguide coaxial coupled circularly polarized antenna provided in the present application;

[0035] Figure 8 A bottom view rotation diagram (bottom view) of a waveguide coaxial coupled circularly polarized antenna provided in the present application;

[0036] Fig. 9 A schematic diagram (cross-sectional view) of the bottom coaxial-to-waveguide structure of a waveguide coaxial coupled circularly polarized antenna provided in this application;

[0037] Fig.10 A schematic diagram (cross-sectional view) of the structure of a bottom coaxial-to-ridge waveguide of a waveguide coaxially coupled circularly polarized antenna provided in this application;

[0038] Fig.11A schematic diagram (top view) of the networking structure of a waveguide coaxial coupled circularly polarized antenna provided in this application.

[0039] Description of reference numerals:

[0040] 1. Ridge waveguide; 101. Upper coupling cavity; 102. Lower coupling cavity; 103. Slit; 104. Ridge waveguide cavity; 105. Through hole; 2. PCB coupling structure; 201. Lower PCB board; 202. Lower coupling plate; 3. PCB radiation structure; 301. Upper PCB board; 302. Upper radiation plate; 4. Isolation wall; 5. Coaxial probe; 501. Thread; 6. Ridge waveguide network. DETAILED DESCRIPTION

[0041] The present application is further described below in detail through specific embodiments in conjunction with the accompanying drawings.

[0042] In the description of this application: unless otherwise specified, the meaning of "plurality" is two or more. The terms "first", "second", "third", etc. in this application are intended to distinguish the objects referred to, and do not have special meanings in terms of technical connotations (for example, they should not be understood as emphasizing the importance or order, etc.). Expressions such as "including", "comprising", "having", etc. also mean "not limited to" (certain units, components, materials, steps, etc.).

[0043] The terms such as "upper", "lower", "left", "right", "middle", etc. cited in this application are usually used to indicate the general relative position relationship for the purpose of intuitive understanding by referring to the drawings, and are not absolute limitations on the position relationship in the actual product.

[0044] See also Figure 1 The present application provides a waveguide coaxial coupled circularly polarized antenna, comprising a ridge waveguide 1, a PCB coupling structure 2 and a PCB radiation structure 3, wherein the ridge waveguide 1 is a metal ridge waveguide 1, the PCB coupling structure 2 is fixedly arranged above the ridge waveguide 1, the PCB radiation structure 3 is arranged above the PCB coupling structure 2, and the PCB coupling structure 2 and the PCB radiation structure 3 are isolated by an isolation wall 4. The peripheral isolation wall 4 of the antenna unit can achieve high isolation between the antenna units on the one hand, and can further improve the antenna axial ratio performance on the other hand.

[0045] See also Figure 1 , Figure 2 and Figure 3An upper coupling cavity 101 is provided on the upper surface of the ridge waveguide 1, and the PCB coupling structure 2 is fixedly arranged above the upper coupling cavity 101. A lower coupling cavity 102 is provided inside the ridge waveguide 1 at an upper position close to the ridge waveguide cavity 104. The upper coupling cavity 101 and the lower coupling cavity 102 are connected through a gap 103, and the lower part of the lower coupling cavity 102 is connected to the ridge waveguide cavity 104 through a through hole 105. A coaxial probe 5 is arranged in the through hole 105 connecting the lower coupling cavity 102 and the ridge waveguide cavity 104, and one end of the coaxial probe 5 extends to the lower coupling cavity 102 and is fixedly connected to the top of the lower coupling cavity 102, and the other end is located in the ridge waveguide cavity 104.

[0046] See also Figure 4 The gap 103 is a U-shaped gap, which can adjust the coupling frequency and the axial ratio. Specifically, the vertical length of the U-shaped gap is mainly used for coupling frequency adjustment, and the horizontal length is mainly used for horizontal and vertical electric field phase adjustment in the upper coupling cavity 101, that is, mainly used for axial ratio adjustment.

[0047] See also Figure 5 The PCB radiation structure 3 includes an upper PCB board 301 and an upper radiation plate 302. The upper radiation plate 302 is fixedly arranged below the upper PCB board 301 and faces the PCB coupling structure 2. The PCB coupling structure 2 includes a lower PCB board 201 and a lower coupling plate 202. The lower coupling plate 202 is fixedly arranged above the lower PCB board 201 and faces the upper radiation plate 302.

[0048] A waveguide coaxial coupled circularly polarized antenna provided in the present application conducts the coaxial signal to the ridge waveguide cavity 104 of the ridge waveguide 1 through the coaxial probe 5, and the signal is transferred from the ridge waveguide cavity 104 to the lower coupling cavity 102 through the through hole 105, and the signal is then coupled to the upper coupling cavity 101 through the gap 103. A lower PCB board 201 with a lower coupling plate 202 is placed on the top of the upper coupling cavity 101, and the signal is transferred to the upper radiation plate 302 of the upper PCB board 301 through the lower coupling plate 202, and finally radiated.

[0049] See also Figure 6 and Figure 7 In the present application, the upper radiation plate 302 and the lower coupling plate 202 are designed to be separated. The upper radiation plate 302 and the lower coupling plate 202 can be rotated or adjusted in size separately, wherein the size is mainly responsible for frequency adjustment, and the rotation angle is mainly used for antenna axial ratio adjustment.

[0050] See also Figure 8 ,Thanks to the single-point center feeding design, when the top antenna rotates, the relative position of the bottom coaxial probe 5 remains unchanged, which is beneficial to improving the axial ratio beam width.

[0051] See also Fig. 9 and Fig.10The present application provides a waveguide coaxial coupling circular polarization antenna coaxial probe 5 that can be in the shape of a screw. For example: The first type: one end of the coaxial probe 5 with a thread 501 passes through the top of the lower coupling cavity 102 and is fixedly arranged at the bottom of the upper coupling cavity 101, and the other end is located in the ridge waveguide cavity 104 (such as Fig. 9 The second type: one end of the coaxial probe 5 with thread 501 passes through the top of the lower coupling cavity 102 and is fixedly set at the bottom of the upper coupling cavity 101, and the other end passes through the bottom of the ridge waveguide cavity 104 and is fixed at the bottom of the ridge waveguide 1 (as shown in FIG. Fig.10 As shown), that is, the bottom coaxial ridge waveguide form.

[0052] The waveguide coaxial coupled circularly polarized antenna provided in the present application can realize antenna array networking. When networking, a single antenna unit can be distributed at both ends of the ridge waveguide network 6. Fig.11 shown.

[0053] The waveguide coaxial coupled circularly polarized antenna provided in this application has the following advantages:

[0054] (1) Using PCB coupling + PCB radiation is beneficial to reducing the size of the antenna unit and achieving a compact layout.

[0055] (2) The introduction of isolation walls can reduce the mutual winding between antenna units and improve the antenna axial ratio and broadband performance.

[0056] (3) Center probe feeding is beneficial to secondary or multiple polarization rotation and improves the axial ratio beam width.

[0057] (4) The screw probe form makes the structure more compact and reduces signal leakage.

[0058] (5) U-shaped gap design to reduce the air coupling size.

[0059] (6) PCB coupling and PCB radiation are independent and can rotate appropriately, thereby improving the axial ratio performance of the antenna unit.

[0060] (7) Pure air coupling form improves antenna efficiency.

[0061] The technical features of the above embodiments may be arbitrarily combined (as long as there is no contradiction in the combination of these technical features). To make the description concise, not all possible combinations of the technical features in the above embodiments are described; these embodiments that are not explicitly written should also be considered to be within the scope of this specification.

Claims

1. A waveguide coaxial coupled circularly polarized antenna, characterized in that: The invention comprises a ridge waveguide, a PCB coupling structure and a PCB radiation structure, wherein the PCB coupling structure is fixedly arranged above the ridge waveguide, the PCB radiation structure is arranged above the PCB coupling structure, and the PCB coupling structure and the PCB radiation structure are isolated by an isolation wall; an upper coupling cavity is provided on the upper surface of the ridge waveguide, the PCB coupling structure is fixedly arranged above the upper coupling cavity, a lower coupling cavity is provided inside the ridge waveguide at an upper position close to the ridge waveguide cavity, the upper coupling cavity and the lower coupling cavity are connected through a gap, the lower part of the lower coupling cavity is connected to the ridge waveguide cavity through a through hole, a coaxial probe is arranged in the through hole connecting the lower coupling cavity with the ridge waveguide cavity, one end of the coaxial probe extends to the lower coupling cavity and is fixedly connected to the top of the lower coupling cavity, and the other end is located in the ridge waveguide cavity.

2. The waveguide coaxial coupled circularly polarized antenna according to claim 1, characterized in that: The PCB radiation structure comprises an upper PCB board and an upper radiation sheet. The upper radiation sheet is fixedly arranged below the upper PCB board and faces the PCB coupling structure.

3. The waveguide coaxial coupled circularly polarized antenna according to claim 2, characterized in that: The PCB coupling structure comprises a lower PCB board and a lower coupling piece, wherein the lower coupling piece is fixedly arranged above the lower PCB board and faces the upper radiation piece.

4. The waveguide coaxial coupled circularly polarized antenna according to claim 3, characterized in that: The upper radiation plate and the lower coupling plate are capable of rotating and adjusting sizes.

5. The waveguide coaxial coupled circularly polarized antenna according to claim 1, characterized in that: The gap is a U-shaped gap.

6. The waveguide coaxial coupled circularly polarized antenna according to claim 5, characterized in that: The U-shaped gap can adjust the coupling frequency and the axial ratio.

7. The waveguide coaxial coupled circularly polarized antenna according to claim 1, characterized in that: The coaxial probe is in the shape of a screw.

8. The waveguide coaxial coupled circularly polarized antenna according to claim 7, characterized in that: One end of the coaxial probe with a thread passes through the top of the lower coupling cavity and is fixedly arranged at the bottom of the upper coupling cavity, and the other end is located in the ridge waveguide cavity.

9. The waveguide coaxial coupled circularly polarized antenna according to claim 7, characterized in that: One end of the coaxial probe with a thread passes through the top of the lower coupling cavity and is fixedly arranged at the bottom of the upper coupling cavity, and the other end passes through the bottom of the ridge waveguide cavity and is fixed at the bottom of the ridge waveguide.

10. The waveguide coaxial coupled circularly polarized antenna according to claim 1, characterized in that: The ridge waveguide is a metal ridge waveguide.

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