Ka-band polarization switching transmission device

Abstract

The invention belongs to the technical field of satellite communication antennas, and particularly discloses a ka-band polarization switching transmission device which comprises a polarization supporting frame arranged on the back face of a main reflecting face, a circular polarizer penetrates through the polarization supporting frame and the main reflecting face, one end of the circular polarizer is coaxially and fixedly connected with an antenna feed source located in the center of the main reflecting face, and the other end of the circular polarizer is coaxially and fixedly connected with the antenna feed source. An inner cavity of the other end of the circular polarizer is aligned with an inner cavity of the duplexer, the duplexer is connected to the polarization supporting frame, a gap is formed between the end face of the duplexer and the end face of the circular polarizer, an annular blind choke groove is formed in the end face, away from the antenna feed source, of the circular polarizer, the choke groove is coaxial with the inner cavity of the circular polarizer, and the gear transmission mechanism is arranged on the polarization supporting frame. A rotation driving device is arranged on a polarization supporting frame, the output end of the rotation driving device is connected with a circular polarizer, and a motion isolation structure is arranged between the circular polarizer and the polarization supporting frame and used for achieving motion isolation. According to the invention, precise polarization rotation switching can be realized, and the device has the advantages of simple structure, stable signal transmission and high reliability.

Description

Technical Field

[0001] The present 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 usually adopt circular polarization. Circular polarization antennas do not need to frequently adjust the polarization angle to maintain correct docking with the satellite. They only need to ensure that their rotation direction is the same as that of the satellite to work. Given that the rotation directions of satellites are divided into left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP), the antenna must have the ability to switch between left and right hand circular polarizations.

[0003] However, the existing polarization rotation switching transmission device changes the direction of the duplexer through physical rotation to achieve polarization rotation switching, that is, it adopts the form of a stationary antenna feed and a rotating duplexer. Sometimes the duplexer drives the microwave channel equipment to rotate together. This mechanical switching method faces many challenges in actual operation. Since the duplexer and microwave channel equipment are usually large in volume and complex in structure, problems such as weight distribution, balance, and selection of the rotation center need to be considered during rotation.

[0004] To solve the problems brought by the overall rotation of the equipment, sometimes an additional rotating joint needs to be added behind the duplexer. Although it can partially alleviate the problems, it also increases the complexity of the system structure and potential failure points. This poses extremely high requirements on the ka-band polarization switching system and may lead to unstable phenomena in the polarization switching rotation process, such as vibration and deviation, 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 the duplexer and microwave channel equipment, and has the advantages of stable system, simple structure, high stability and reliability of signal transmission.

[0006] To achieve the above purpose, the specific technical solution of the present invention is as follows:

[0007] A Ka-band polarization switching drive device includes an antenna feed, a main reflector, a polarization support frame, a circular polarizer, and a duplexer. The polarization support frame is disposed on the back of the main reflector. The circular polarizer passes through the polarization support frame and the main reflector. One end of the circular polarizer is coaxially and fixedly connected to the antenna feed located at the center of the main reflector. The inner cavity at 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. There is a gap between the end face of the duplexer and the end face of the circular polarizer. An annular choke groove is provided on the end face of the circular polarizer away from the antenna feed. The choke groove is coaxially arranged with the inner cavity of the circular polarizer, and the choke groove is a blind groove. And,

[0008] A gear transmission mechanism is disposed on the polarization support frame and includes a rotation driving device, a first gear, and a second gear. The rotation driving device is fixedly arranged on the polarization support frame. The first gear is sleeved and fixed on the output shaft of the rotation driving device. The first gear meshes with the second gear. The second gear is coaxially sleeved and fixed on the circular polarizer.

[0009] A motion isolation structure is disposed between the circular polarizer and the polarization support frame for achieving motion isolation between the circular polarizer and the polarization support frame.

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

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

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

[0013] Further, the rotation driving device is one of a servo motor, a stepper motor combined with an encoder, a servo motor cooperating with a field-oriented control FOC system, and a brushless DC motor cooperating with a field-oriented control FOC system.

[0014] Further, the gear transmission mechanism can be replaced by a worm and worm gear transmission mechanism or a planetary gear transmission mechanism.

[0015] Further, the coaxial sleeved and fixed connection between the second gear and the circular polarizer is realized by key connection.

[0016] Further, a mechanical limit structure is further included to prevent the rotation angle of the circular polarizer from exceeding the limit.

[0017] Furthermore, the mechanical limit structure includes:

[0018] A limit block, arranged on the second gear;

[0019] A first limit platform and a second limit platform, respectively arranged on both sides of the polarization support frame, for realizing the ultimate limit of the limit block.

[0020] Compared with the prior art, a ka-band polarization switching transmission device of the present invention adopts a cooperation of 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 groove in terms of structure, realizes fast and smooth polarization switching, meets the requirements of high-speed communication, realizes high-precision switching of polarization rotation directions, the gap cooperates with the choke groove, utilizes the propagation characteristics of electromagnetic waves, effectively isolates the mechanical connection between the circular polarizer and the duplexer, enables the circular polarizer to rotate freely without external resistance, while the duplexer element remains fixed, and at the same time avoids microwave leakage and signal attenuation or distortion caused by movement, ensuring high-quality signal transmission. The overall structure of the present invention is simple, 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 service life of the system, taking into account the dual optimization of mechanical and microwave signals, and utilizing the integration and collaborative work of components, so as to realize precise polarization rotation direction switching without changing the relative positions of the duplexer and the microwave channel equipment, having the advantages of stable system, simple structure, stable signal transmission and high reliability, being highly practical and worthy of popularization. Description of the Drawings

[0021] Figure 1 Schematic diagram of the overall structure of the present invention Figure 1 .

[0022] Figure 2 Schematic diagram of the overall structure of the present invention Figure 2 .

[0023] Figure 3 Schematic diagram of the partial structure of the present invention Figure 1 .

[0024] Figure 4 Schematic diagram of the partial structure of the present invention Figure 2 .

[0025] Figure 5 Schematic diagram of the partial structure of the present invention Figure 3 .

[0026] Figure 6 Enlarged view A of the partial structure of the present invention.

[0027] Figure 7Schematic diagram of the mechanical limit 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. Specific embodiments

[0030] Currently, Ka-band antennas usually adopt circular polarization. Circularly polarized antennas do not need to frequently adjust the polarization angle to maintain correct docking with satellites, and only need to ensure that their rotation direction is the same as that of the satellite to work. Given that the rotation directions of satellites are divided into left-handed circular polarization LHCP and right-handed circular polarization RHCP, the antenna must have the ability to switch between left and right hand polarizations. However, the existing polarization rotation direction switching transmission device changes the direction of the duplexer through physical rotation to achieve the switching of the polarization rotation direction, that is, it adopts the form of the antenna feed being stationary and the duplexer rotating. Sometimes, the duplexer drives the microwave channel equipment to rotate together. This mechanical switching method faces many challenges in actual operation.

[0031] Since the duplexer and microwave channel equipment are usually large in volume and complex in structure, when rotating, issues such as their weight distribution, balance, and the selection of the rotation center need to be considered. This not only increases the complexity of the system but also may lead to unstable phenomena during rotation, such as vibration and deviation, thereby affecting the stability and reliability of signal transmission.

[0032] In summary, in view of the technical problem that the instability of the system affects 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 and implement the technical solutions of the present invention, the following will combine the attached Figure 1 To the attached Figure 7 to clearly and elaborately describe the technical solutions in the present invention.

[0034] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is 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 operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0035] In addition, it should be further noted 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. The "and / or" in the text is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of the present invention, "a plurality" means two or more than two.

[0036] The following terms "first", "second", "third", "fourth" are only used for descriptive purposes and should not be construed as implying or indicating relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third", "fourth" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more than two.

[0037] Embodiment 1

[0038] As Figures 1 to 4 shown, a ka-band polarization switching transmission device provided by the present invention includes 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 cooperation of the above structures effectively ensures the reliability of the entire system and the stability of signal transmission.

[0039] Specifically, as Figure 1 shown, a polarization support frame 3 is installed on the back of the main reflector 2, and the gear transmission mechanism 7 is arranged on the polarization support frame 3. As Figure 3As shown in the figure, the gear transmission mechanism 7 includes a rotary drive device 71, a first gear 72, and a second gear 73. The rotary drive device 71 can be selected as a servo motor. The gear transmission mechanism 7 uses a small servo motor as the power source. The servo motor is fixedly connected to the polarization support frame 3. A first gear 72 is fixedly sleeved on the output shaft of the servo motor. The first gear 72 serves as the driving wheel. The first gear 72 meshes with the second gear 73. The second gear 73 serves as the driven wheel. The second gear 73 is coaxially fixedly sleeved on the circular polarizer 4. The circular polarizer 4 passes 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 at 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] To ensure that during the polarization rotation direction switching process, the circular polarizer 4 can rotate independently without affecting the state of the rear-end duplexer 5, as Figure 5 and Figure 6 shown, a movement isolation gap 6 is provided between the end face of the duplexer 5 and the end face of the circular polarizer 4. This gap 6 is mainly used to prevent the circular polarizer 4 from rubbing against the duplexer 5 when it rotates.

[0041] The design of the above gap 6 makes use of the propagation characteristics of electromagnetic waves under specific conditions. When the electromagnetic wave passes through this narrow gap 6, since the size of the gap 6 is much smaller than the wavelength, most of the energy can pass through the gap 6 smoothly without being significantly affected by impedance. To ensure performance, the gap 6 is designed to be as small as possible. The width dimension range of the designed gap 6 is from 0.05 mm to 0.15 mm.

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

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

[0044] To avoid microwave signal leakage caused by the existence of this gap 6, a choke groove is provided on the end face of the circular polarizer 4. This choke groove is an annular blind groove and is coaxially arranged with the inner cavity of the circular polarizer 4.

[0045] The gap 6 and the choke groove cooperate. On the one hand, the mechanically designed gap 6 effectively isolates the mechanical connection between the circular polarizer 4 and the duplexer 5. On the other hand, the choke groove ensures the normal transmission of signals and prevents and suppresses microwave leakage.

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

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

[0048] During use, when the servo motor is started, the output shaft of the servo motor drives the first gear 72 to rotate, causing the second gear 73 and the circular polarizer 4 to rotate synchronously, and driving the antenna feed 1 closely connected to the front end of the circular polarizer 4 to rotate precisely synchronously, 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 the rear end is fixed, maintaining the stability of the duplexer 5 part, avoiding the increase in system complexity due to issues such as weight distribution and balance in microwave channel equipment, and more importantly, avoiding signal attenuation or distortion problems caused by movement.

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

[0051] Specifically, the movement isolation structure 8 includes a first bearing 81 and a second bearing 82 provided at both ends of the circular polarizer 4. The first bearing 81 and the second bearing 82 are respectively provided on both sides of the second gear 73. The inner rings of the first bearing 81 and the second bearing 82 are respectively sleeved and fixed with the circular polarizer 4, and the outer rings of the first bearing 81 and the second bearing 82 are respectively sleeved and fixed with 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 surrounding polarization support frame 3 through the first bearing 81 and the second bearing 82, minimizing the influence of the friction force on the rotation of the circular polarizer 4 and making the rotation smoother.

[0053] It should be noted that the power source part involved in the present invention adopts a rotary drive device 71 capable of achieving precise positioning and control. The rotary drive device 71 is not limited to traditional servo motors, but also includes alternative solutions capable of providing precise position control such as, but not limited to, a stepper motor combined with an encoder, a servo motor, and a brushless DC motor cooperating with a field-oriented control FOC system.

[0054] In addition, the power transmission mechanism of the present invention adopts a transmission device capable of effectively transmitting rotational motion and achieving speed reduction and torque increase. It is not limited to the gear transmission mechanism 7, but also covers various forms of transmission structures such as worm and worm gear transmission and planetary gear transmission.

[0055] In the present invention, the circular polarizer 4 drives the antenna feed 1 to rotate ±90° in the clockwise or counterclockwise direction, which can realize the function of left-handed or right-handed polarization switching of the antenna. To ensure the safety and accuracy of this process, in actual operation, it is achieved by controlling the rotation angle of the servo motor, that is, forming a soft limit for angle control at the software level 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, as Figure 7 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 for realizing the ultimate limit of the limit block 91. In this way, even when 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 in the physical structure will play a role. The first limit platform 92 and the second limit platform 93 form the ultimate limit structures on both sides, abut against the limit block 91, and prevent the second gear 73 from continuing to rotate, thereby protecting the device from damage. This dual-insurance design not only ensures the normal operation of the system but also improves the overall safety and reliability.

[0057] In summary, a ka-band polarization switching transmission device provided by the present invention realizes fast and smooth polarization switching, meets the requirements of high-speed communication, realizes high-precision switching of the polarization rotation direction. The gap 6 and the choke groove utilize the propagation characteristics of electromagnetic waves, effectively isolate the mechanical connection between the circular polarizer 4 and the duplexer 5, enabling the circular polarizer 4 to rotate freely without external resistance, while the duplexer 5 components remain fixed, and at the same time avoiding microwave leakage and signal attenuation or distortion caused by movement, ensuring high-quality signal transmission. The overall structure is simple, reducing complex mechanical components, lowering the failure rate and maintenance cost of the system, and also reducing the vibration and wear problems caused by rotation, further improving the stability and service life of the system, taking into account the dual optimization of mechanical and microwave signals, and realizing fast and smooth polarization switching by using the integration and collaborative work of components, improving the reliability of the system and the stability of signal transmission.

[0058] It can be understood that the present invention is described through some embodiments. Those skilled in the art know that various changes or equivalent replacements can be made to these features and embodiments without departing from the spirit and scope of the present invention.

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

Claims

1. A Ka-band polarization switching transmission device, characterized in that: The invention comprises an antenna feed source (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 side of the main reflector (2), the circular polarizer (4) is arranged on 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), a gap (6) is arranged between the end face of the duplexer (5) and the end face of the circular polarizer (4), an annular choke slot is arranged on the end face of the circular polarizer (4) away from the antenna feed source (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) is 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 sleeved and fixed 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 sleeved 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).

2. The Ka-band polarization switching transmission device according to claim 1, characterized in that: The motion isolation structure (8) comprises a first bearing (81) and a second bearing (82) arranged at two 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 fitted and fixed to the circular polarizer (4); and the outer rings of the first bearing (81) and the second bearing (82) are respectively fitted and fixed to the polarization support frame (3).

3. 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.

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

5. 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.

6. 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.

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

8. 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 rotating beyond a limit.

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

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