A Ka-band polarization switching transmission device

Abstract

The present invention belongs to the technical field of satellite communication antennas, and specifically discloses a Ka-band polarization switching transmission device, comprising a polarization support frame arranged on the back side of a main reflector, a circular polarizer passing through the polarization support frame and the main reflector, one end of the circular polarizer being coaxially fixedly connected to an antenna feed located at the center of the main reflector, an inner cavity at the other end of the circular polarizer being aligned with an inner cavity of a duplexer, the duplexer being connected to the polarization support frame, a gap being provided between an end face of the duplexer and an end face of the circular polarizer, an annular blind slot choke slot being provided on an end face of the circular polarizer away from the antenna feed, the choke slot being coaxial with the inner cavity of the circular polarizer, a gear transmission mechanism being provided on the polarization support frame, a rotation drive device being provided on the polarization support frame, an output end being connected to the circular polarizer, and a motion isolation structure being provided between the circular polarizer and the polarization support frame for achieving motion isolation. The present invention can achieve precise polarization rotation switching, and has the advantages of simple structure, stable signal transmission, and high reliability.

Description

Technical Field

[0001] The invention belongs to the technical field of satellite communication antennas and relates to a Ka-band polarization switching transmission device. Background Art

[0002] Ka-band antennas typically use circular polarization. Circularly polarized antennas do not require frequent polarization adjustments to maintain proper alignment with satellites; they simply need to align their rotation with the satellite. Since satellites rotate in either left-hand circular polarization (LHCP) or right-hand circular polarization (RHCP), antennas must be able to switch between left and right directions.

[0003] However, existing polarization direction switching transmission devices achieve polarization direction switching by changing the direction of the duplexer through physical rotation. That is, the antenna feed source is stationary and the duplexer rotates. Sometimes the duplexer drives the microwave channel equipment to rotate together. This mechanical switching method faces many challenges in actual operation. Because the duplexer and microwave channel equipment are usually large and complex in structure, their weight distribution, balance, and the selection of the rotation center need to be considered during rotation.

[0004] To solve the problems caused by the overall rotation of the equipment, it is sometimes necessary to add additional rotation joints behind the duplexer. Although this can partially alleviate the problem, it also increases the complexity of the system structure and potential failure points. This places extremely high demands on the Ka-band polarization switching system. At the same time, it may cause system instability during the polarization switching rotation process, such as vibration and offset, affecting the stability and reliability of signal transmission. Summary of the Invention

[0005] The purpose of the present invention is to provide a Ka-band polarization switching transmission device that can achieve precise polarization rotation switching without changing the relative positions of a duplexer and a microwave channel device, and has the advantages of system stability, simple structure, and high stability and reliability of signal transmission.

[0006] To achieve the above object, the specific technical solutions of the present invention are as follows:

[0007] A Ka-band polarization switching transmission device includes an antenna feed, a main reflector, a polarization support frame, a circular polarizer, and a duplexer, wherein the polarization support frame is arranged on the back of the main reflector, the circular polarizer is inserted into the polarization support frame and the main reflector, one end of the circular polarizer is coaxially fixedly connected to the antenna feed located at the center of the main reflector, the inner cavity of the other end of the circular polarizer is aligned with the inner cavity of the duplexer, the duplexer is fixedly connected to the polarization support frame, a gap is provided between the end face of the duplexer and the end face of the circular polarizer, an annular choke slot is provided on the end face of the circular polarizer away from the antenna feed, the choke slot is coaxially arranged with the inner cavity of the circular polarizer, and the choke slot is a blind slot, and,

[0008] A gear transmission mechanism is provided on the polarization support frame, comprising a rotation drive device, a first gear, and a second gear. The rotation drive device is fixedly provided on the polarization support frame, the first gear is fixedly mounted on the output shaft of the rotation drive device, the first gear is meshed with the second gear, and the second gear is coaxially mounted on the circular polarizer.

[0009] The motion isolation structure is arranged between the circular polarizer and the polarization support frame, and is used to achieve motion isolation between the circular polarizer and the polarization support frame.

[0010] Furthermore, the motion isolation structure includes a first bearing and a second bearing arranged at both ends of the circular polarizer, the first bearing and the second bearing are respectively arranged on both sides of the second gear, the inner rings of the first bearing and the second bearing are respectively fixed to the circular polarizer, and the outer rings of the first bearing and the second bearing are respectively fixed to the polarization support frame.

[0011] Furthermore, the width of the gap is 0.05 mm to 0.15 mm.

[0012] Furthermore, the width of the gap is 0.1 mm.

[0013] Furthermore, the rotation drive device is one of a steering gear, a stepper motor combined with an encoder, a servo motor combined with a field oriented control FOC system, and a brushless DC motor combined with a field oriented control FOC system.

[0014] Furthermore, the gear transmission mechanism may be replaced by a worm gear transmission mechanism or a planetary gear transmission mechanism.

[0015] Furthermore, the coaxial fixed connection between the second gear and the circular polarizer is achieved by a key connection.

[0016] Furthermore, a mechanical limiting structure is included to prevent the circular polarizer from rotating beyond a limit.

[0017] Furthermore, the mechanical limiting structure includes:

[0018] a limiting block, arranged on the second gear;

[0019] The first limiting platform and the second limiting platform are respectively arranged on both sides of the polarization support frame, and are used to achieve the ultimate limiting of the limiting block.

[0020] Compared with the prior art, the Ka-band polarization switching transmission device of the present invention structurally adopts an antenna feed, a main reflector, a polarization support frame, a circular polarizer, a duplexer, a gear transmission mechanism, a motion isolation structure, a gap and a choke slot to cooperate to achieve fast and smooth polarization switching, meet the needs of high-speed communication, and realize high-precision switching of polarization rotation. The gap is matched with the choke slot, and the propagation characteristics of electromagnetic waves are utilized to effectively isolate the mechanical connection between the circular polarizer and the duplexer, so that the circular polarizer can rotate freely without external resistance, while the duplexer elements remain fixed, while avoiding microwave leakage and signal attenuation or distortion caused by movement, ensuring high-quality signal transmission. The overall structure of the present invention is simple, which reduces complex mechanical components, reduces the failure rate and maintenance cost of the system, and also reduces the vibration and wear problems caused by rotation, further improving the stability and life of the system. It takes into account the dual optimization of mechanical and microwave signals, and utilizes the integration and collaborative work of components to achieve precise polarization rotation switching without changing the relative positions of the duplexer and the microwave channel equipment. It has the advantages of system stability, simple structure, stable signal transmission and high reliability, is highly practical, and is worthy of promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The overall structure of the present invention is shown in FIG. Figure 1 .

[0022] Figure 2 The overall structure of the present invention is shown in FIG. Figure 2 .

[0023] Figure 3 It is a schematic diagram of the local structure of the present invention Figure 1 .

[0024] Figure 4 It is a schematic diagram of the local structure of the present invention Figure 2 .

[0025] Figure 5 It is a schematic diagram of the local structure of the present invention Figure 3 .

[0026] Figure 6 It is the enlarged view A of the local structure of the present invention.

[0027] Figure 7Schematic diagram of the mechanical limiting structure of the present invention Figure 4 .

[0028] Reference numerals:

[0029] 1. Antenna feed; 2. Main reflector; 3. Polarization support frame; 4. Circular polarizer; 5. Duplexer; 6. Gap; 7. Gear transmission mechanism; 71. Rotation drive device; 72. First gear; 73. Second gear; 8. Motion isolation structure; 81. First bearing; 82. Second bearing; 9. Mechanical limit structure; 91. Limit block; 92. First limit platform; 93. Second limit platform. DETAILED DESCRIPTION

[0030] Currently, Ka-band antennas typically use circular polarization. Circularly polarized antennas do not require frequent adjustment of polarization angles to maintain proper docking with satellites; they only need to ensure that their rotation direction is consistent with that of the satellite. Given that satellites can rotate in either left-hand circular polarization (LHCP) or right-hand circular polarization (RHCP), antennas must be able to switch between left and right directions. However, existing polarization direction switching transmission devices physically rotate the duplexer to achieve polarization direction switching. This involves rotating the duplexer while the antenna feed is stationary. Sometimes, the duplexer drives the microwave channel equipment to rotate together. This mechanical switching method faces many challenges in actual operation.

[0031] Because duplexers and microwave channel equipment are typically large and complex, rotation requires consideration of weight distribution, balance, and the selection of the rotation center. This not only increases system complexity but can also lead to instabilities during rotation, such as vibration and offset, which can affect the stability and reliability of signal transmission.

[0032] In summary, in order to address the technical problem of system instability affecting the stability and reliability of signal transmission, the present invention provides a new Ka-band polarization switching transmission device.

[0033] In order to enable those skilled in the art to better understand the technical solution of the present invention and to implement it, the following Figure 1 To the attached Figure 7 , clearly and comprehensively describe the technical solutions in the present invention.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0035] In addition, it should be further explained that in the description of the embodiments of the present invention, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present invention, "multiple" refers to two or more than two.

[0036] The terms "first," "second," "third," and "fourth" below are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of the technical features indicated. Thus, features qualified as "first," "second," "third," and "fourth" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0037] Example 1

[0038] like Figures 1 to 4 As shown, the present invention provides a Ka-band polarization switching transmission device, including an antenna feed 1, a main reflector 2, a polarization support frame 3, a circular polarizer 4, a gear transmission mechanism 7, a motion isolation structure 8 and a duplexer 5. The mutual coordination of the above structures effectively ensures the reliability of the entire system and the stability of signal transmission.

[0039] Specifically, such as Figure 1 As shown, a polarization support frame 3 is installed on the back of the main reflector 2, and a gear transmission mechanism 7 is arranged on the polarization support frame 3. Figure 3As shown, the gear transmission mechanism 7 includes a rotation drive device 71, a first gear 72 and a second gear 73. The rotation drive device 71 can be selected as a steering gear. The gear transmission mechanism 7 uses a small steering gear as a power source. The steering gear is fixedly connected to the polarization support frame 3. The first gear 72 is fixedly mounted on the output shaft of the steering gear. The first gear 72 exists as a driving wheel. The first gear 72 is engaged with the second gear 73. The second gear 73 exists as a driven wheel. The second gear 73 is coaxially mounted and fixed on the circular polarizer 4. The circular polarizer 4 is passed through the polarization support frame 3 and the main reflector 2. One end of the circular polarizer 4 is coaxially fixedly connected to the antenna feed source 1 located at the center of the main reflector 2. The inner cavity of the other end of the circular polarizer 4 is aligned with the inner cavity of the duplexer 5. The duplexer 5 is fixedly connected to the polarization support frame 3.

[0040] In order to ensure that the circular polarizer 4 can rotate independently during the polarization direction switching process without affecting the state of the duplexer 5 at the rear end, as shown in FIG. Figure 5 and Figure 6 As shown, a motion isolation gap 6 is provided between the end face of the duplexer 5 and the end face of the circular polarizer 4. The gap 6 is mainly used to prevent the circular polarizer 4 from rubbing against the duplexer 5 when the circular polarizer 4 rotates.

[0041] The design of gap 6 exploits the propagation characteristics of electromagnetic waves under specific conditions. Because gap 6 is much smaller than the wavelength, most of the energy can pass smoothly through this narrow gap 6 without being significantly affected by impedance. To ensure performance, gap 6 is designed to be as small as possible, with a width ranging from 0.05mm to 0.15mm.

[0042] Preferably, the width of the gap 6 is 0.1 mm.

[0043] The gap 6 effectively isolates the mechanical connection between the circular polarizer 4 and the duplexer 5, so that the circular polarizer 4 can rotate freely without external resistance, while the duplexer 5 components remain fixed.

[0044] In order to avoid leakage of microwave signals due to the existence of the gap 6 , a choke slot is provided on the end face of the circular polarizer 4 . The choke slot is an annular blind slot and is coaxially arranged with the inner cavity of the circular polarizer 4 .

[0045] The gap 6 cooperates with the choke slot. On the one hand, the structurally designed gap 6 can effectively isolate the mechanical connection between the circular polarizer 4 and the duplexer 5. On the other hand, the choke slot ensures the normal transmission of the signal and prevents and suppresses microwave leakage.

[0046] Specifically, the coaxial fixed connection between the second gear 73 and the circular polarizer 4 is achieved by a key connection.

[0047] The present invention utilizes the combination of the gear transmission mechanism 7 and the servo to ensure accurate switching of the polarization rotation direction. The servo is used as a power source to drive the first gear 72 to rotate, and the engagement between the gears drives the second gear 73 and the circular polarizer 4 thereon to rotate accurately.

[0048] During use, the servo is started, and the output shaft of the servo drives the first gear 72 to rotate, so that the second gear 73 and the circular polarizer 4 rotate synchronously, driving the antenna feed source 1 closely connected to the front end of the circular polarizer 4 to rotate synchronously and accurately, ensuring the accurate conversion of the polarization state.

[0049] During this process, the front end of the circular polarizer 4 is closely connected to the antenna feed 1, ensuring the accurate conversion of the polarization state, while its rear end is fixed, maintaining the stability of the duplexer 5 part, avoiding the microwave channel equipment from increasing the system complexity due to considerations such as weight distribution and balance, and more importantly, avoiding signal attenuation or distortion caused by movement.

[0050] In order to prevent the movement of the circular polarizer 4 from being disturbed by surrounding components, a motion isolation structure 8 is provided between the circular polarizer 4 and the polarization support frame 3 .

[0051] Specifically, the motion isolation structure 8 includes a first bearing 81 and a second bearing 82 arranged at both ends of the circular polarizer 4. The first bearing 81 and the second bearing 82 are respectively arranged on both sides of the second gear 73. The inner rings of the first bearing 81 and the second bearing 82 are respectively fixed to the circular polarizer 4, and the outer rings of the first bearing 81 and the second bearing 82 are respectively fixed to the polarization support frame 3.

[0052] When the middle circular polarizer 4 rotates under the action of the gear transmission mechanism 7, the rotation of the circular polarizer 4 can be isolated from the outer polarization support frame 3 by the first bearing 81 and the second bearing 82, so that the rotation of the circular polarizer 4 is minimally affected by the friction force and the rotation is smoother.

[0053] It should be noted that the power source part involved in the present invention adopts a rotary drive device 71 that can achieve precise positioning and control. The rotary drive device 71 is not limited to traditional servos, but also includes but is not limited to stepper motors combined with encoders, servo motors, brushless DC motors with magnetic field oriented control FOC systems, etc., which can provide alternative solutions for precise position control.

[0054] In addition, the power transmission mechanism of the present invention adopts a transmission device that can effectively transmit rotational motion and achieve deceleration and torque increase, which is not limited to the gear transmission mechanism 7, but also covers various forms of transmission structures such as worm gear transmission and planetary gear transmission.

[0055] In the present invention, the circular polarizer 4 drives the antenna feed 1 to rotate ±90° clockwise or counterclockwise, which can achieve the left-hand or right-hand switching function of the antenna polarization. To ensure the safety and accuracy of this process, in actual operation, it is achieved by controlling the rotation angle of the servo, that is, forming a software-level angle control soft limit to ensure that it only operates within the range of ±90°. In addition, considering the possible failure risk of the software, an additional mechanical limit structure 9 is designed as a supplement.

[0056] Specifically, if Figure 7 As shown, the mechanical limit structure 9 includes a raised limit block 91 provided on the second gear 73, and a first limit platform 92 and a second limit platform 93 are provided at corresponding positions on both sides of the polarization support frame 3 to achieve the extreme limit of the limit block 91. In this way, even if the soft limit control of the angle control at the software level fails, when the device attempts to rotate more than +90° or less than -90°, the hard limit on the physical structure will come into play, and the first limit platform 92 and the second limit platform 93 will form an extreme limit structure on both sides, abutting against the limit block 91, preventing the second gear 73 from continuing to rotate, thereby protecting the device from damage. This double insurance design not only ensures the normal operation of the system, but also improves the overall safety and reliability.

[0057] In summary, the Ka-band polarization switching transmission device provided by the present invention achieves fast and smooth polarization switching, meets the needs of high-speed communication, and realizes high-precision switching of polarization rotation. The gap 6 and the choke slot utilize the propagation characteristics of electromagnetic waves to effectively isolate the mechanical connection between the circular polarizer 4 and the duplexer 5, allowing the circular polarizer 4 to rotate freely without external resistance, while the duplexer 5 components remain fixed. At the same time, microwave leakage and signal attenuation or distortion caused by movement are avoided, ensuring high-quality signal transmission. The overall structure is simple, reducing complex mechanical components, reducing the system's failure rate and maintenance costs, while also reducing vibration and wear caused by rotation, further improving the system's stability and lifespan. It takes into account the dual optimization of mechanical and microwave signals, and utilizes the integration and collaborative work of components to achieve fast and smooth polarization switching, improving the system's reliability and signal transmission stability.

[0058] It will be understood that the present invention is described through some embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention.

[0059] Furthermore, these features and embodiments may be modified to suit specific circumstances and materials under the teachings of the present invention without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present invention are intended to be protected by the present invention.

Claims

1. A Ka-band polarization switching transmission device, characterized in that: The invention comprises an antenna feed (1), a main reflector (2), a polarization support frame (3), a circular polarizer (4) and a duplexer (5), wherein the polarization support frame (3) is arranged on the back of the main reflector (2), the circular polarizer (4) is passed through the polarization support frame (3) and the main reflector (2), one end of the circular polarizer (4) is coaxially fixedly connected to the antenna feed (1) located at the center of the main reflector (2), the inner cavity of the other end of the circular polarizer (4) is aligned with the inner cavity of the duplexer (5), the duplexer (5) is fixedly connected to the polarization support frame (3), a gap (6) is provided between the end face of the duplexer (5) and the end face of the circular polarizer (4), an annular choke slot is provided on the end face of the circular polarizer (4) away from the antenna feed (1), the choke slot is coaxially arranged with the inner cavity of the circular polarizer (4), and the choke slot is a blind slot, and, a gear transmission mechanism (7), arranged on the polarization support frame (3), comprising a rotation drive device (71), a first gear (72) and a second gear (73); the rotation drive device (71) is fixedly arranged on the polarization support frame (3); the first gear (72) is fixedly mounted on the output shaft of the rotation drive device (71); the first gear (72) is meshed with the second gear (73); and the second gear (73) is coaxially mounted and fixed on the circular polarizer (4); A motion isolation structure (8) is arranged between the circular polarizer (4) and the polarization support frame (3) and is used to achieve motion isolation between the circular polarizer (4) and the polarization support frame (3); the motion isolation structure (8) includes a first bearing (81) and a second bearing (82) arranged at both ends of the circular polarizer (4), the first bearing (81) and the second bearing (82) are respectively arranged on both sides of the second gear (73), the inner rings of the first bearing (81) and the second bearing (82) are respectively fixedly mounted on the circular polarizer (4), and the outer rings of the first bearing (81) and the second bearing (82) are respectively fixedly mounted on the polarization support frame (3).

2. The Ka-band polarization switching transmission device according to claim 1, characterized in that: The width of the gap (6) is 0.05 mm to 0.15 mm.

3. The Ka-band polarization switching transmission device according to claim 2, characterized in that: The width of the gap (6) is 0.1 mm.

4. The Ka-band polarization switching transmission device according to claim 1, characterized in that: The rotary drive device (71) is one of a steering gear, a stepper motor combined with an encoder, a servo motor combined with a magnetic field oriented control FOC system, and a brushless DC motor combined with a magnetic field oriented control FOC system.

5. The Ka-band polarization switching transmission device according to claim 1, characterized in that: The gear transmission mechanism (7) can be replaced by a worm gear transmission structure or a planetary gear transmission structure.

6. The Ka-band polarization switching transmission device according to claim 1, characterized in that: The coaxial fixed connection between the second gear (73) and the circular polarizer (4) is achieved by a key connection.

7. The Ka-band polarization switching transmission device according to claim 1, characterized in that: It also includes a mechanical limiting structure (9) for preventing the circular polarizer (4) from exceeding the rotation angle limit.

8. The Ka-band polarization switching transmission device according to claim 7, characterized in that: The mechanical limiting structure (9) comprises: A limit block (91) is provided on the second gear (73); The first limiting platform (92) and the second limiting platform (93) are respectively arranged on both sides of the polarization support frame (3) and are used to achieve the ultimate limiting of the limiting block (91).

Images