Ku band polarization fine tuning mechanism in a c / ku feed network

Abstract

The application discloses a Ku-band polarization fine adjustment mechanism in a C / Ku feed network, and belongs to the technical field of satellite communication and radio astronomy. The Ku-band polarization fine adjustment mechanism comprises a motor, a transmission shaft, a top plate, a quadrature mode coupler, a rotating support structure, an upper support disc and a lower support disc. The bottom end of the quadrature mode coupler is connected to the upper surface of the upper support disc through the rotating support structure, the center of the upper support disc is located on the central axis of the quadrature mode coupler, and the quadrature mode coupler can rotate around the central axis. The motor drives the transmission structure to rotate. The mechanical rotation of the Ku-band quadrature mode coupler and the connected waveguide realizes the Ku-band polarization fine adjustment in the C / Ku feed network, the Ku-band output port is extended to outside the feed rear mounting disc, and the installation and replacement of a Ku-band low-noise amplifier are facilitated. The application is also applicable to Ku / Ka, X / Ku / Ka and other band dual-frequency, multi-frequency shared multi-lens feed antenna systems.

Description

Technical Field

[0001] This invention relates to the fields of satellite communication and radio astronomy, and in particular to a Ku-band polarization fine-tuning mechanism in a C / Ku feed network. Background Technology

[0002] The Faraday rotation angle of electromagnetic waves propagating through the ionosphere is inversely proportional to the square of the frequency. When a dual-band feed operates in online polarization mode, there will be a deviation in the polarization angle. In the C / Ku dual-band feed widely used in satellite communications, the polarization deviation between the C-band and Ku-band can be as high as ten degrees at different locations in China and corresponding to different satellite positions, which cannot be ignored. Therefore, when the C and Ku bands operate simultaneously, the C / Ku dual-band feed requires a Ku-band polarization fine-tuning structure to fine-tune the Ku-band polarization angle to eliminate the influence of the Faraday rotation.

[0003] In engineering, two common methods are used to achieve Ku-band polarization fine-tuning in C / Ku dual-frequency feeds:

[0004] 1. Rotating Ku-band orthogonal mode coupler. The polarization state of the Ku-band is determined by the orthogonal mode coupler. When linearly polarized, rotating the Ku-band orthogonal mode coupler deflects the Ku-band polarization angle.

[0005] 2. Use a 180° phase shifter. Configure a 180° phase shifter before the common port of the Ku-band quadrature mode coupler. Rotating the 180° phase shifter will deflect the Ku-band output polarization angle by 2°.

[0006] Existing processes have various drawbacks:

[0007] 1. The Ku-band orthogonal mode coupler is rotated directly in the middle of the network, and the Ku-band low-noise amplifier is installed in the middle of the network and rotates with the orthogonal mode coupler. Because the feed network is installed inside the antenna center, the front and rear plates of the feed network are installed and fixed inside the center. After the rear plate of the feed network is fixed, it blocks the space for replacing components in the middle of the network. If the low-noise amplifier in the middle of the feed is damaged, the feed can only be hoisted for replacement, which is inconvenient.

[0008] 2. The 180° phase shifter used in the project cannot be phase-shifted by 180° at every frequency point in the entire operating frequency band. Only one or two frequency points are phase-shifted by 180°, and most frequency points in the frequency band have phase shift deviation. The phase shift deviation degrades the cross polarization of the system and reduces the system signal-to-noise ratio. Summary of the Invention

[0009] The purpose of this invention is to provide a Ku-band polarization fine-tuning mechanism in a C / Ku feed network, which solves the problem of difficulty in replacing the low-noise amplifier of the mechanically rotated Ku-band orthogonal mode coupler. By extending the Ku-band output port of the Ku-band polarization fine-tuning mechanism to the rear plate of the feed network, it is possible to easily access the antenna center body to replace the Ku-band low-noise amplifier.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A Ku-band polarization fine-tuning mechanism in a C / Ku feed network includes a motor, a drive shaft, a top plate, an orthogonal mode coupler 1, a rotary support structure 3, an upper support plate, and a lower support plate. The bottom end of the orthogonal mode coupler is connected to the upper surface of the upper support plate through the rotary support structure. The center of the upper support plate is located on the central axis of the orthogonal mode coupler, and the orthogonal mode coupler can rotate around its central axis.

[0012] The upper support plate has a first arc-shaped hole and an upper shaft hole. The top end of the orthogonal mode coupler is connected to the top plate bearing through a waveguide rotary joint. The lower support plate is located below the upper support plate. The lower support plate has a second arc-shaped hole and a lower shaft hole. A connecting waveguide connected to one side of the orthogonal mode coupler extends vertically downward, passing through the first arc-shaped hole of the upper support plate and the second arc-shaped hole of the lower support plate. The upper surface of the lower support plate is also provided with a waveguide support structure connected to its bearing. A driven gear is fixed on the outer wall of the waveguide support structure.

[0013] The motor is mounted on the lower support plate via a motor bracket, and the driving gear and driven gear on the motor drive shaft mesh together.

[0014] The top plate is also provided with a fixed shaft hole. The top end of the transmission shaft is connected to the fixed shaft hole bearing, and its bottom end passes through the upper shaft hole and is connected to the lower shaft hole bearing. Both the upper and lower halves of the transmission shaft are provided with transmission gears. A driven gear two is fixed on the outer wall of the rotating support structure. The transmission gear of the lower half of the transmission shaft is located on one side of the driven gear one and meshes with it. The transmission gear of the upper half of the transmission shaft and the driven gear two are located on the same plane, and the transmission gear and the driven gear two mesh with each other.

[0015] Furthermore, the drive shaft is connected to the upper shaft bore bearing.

[0016] Furthermore, the central axis of the waveguide support structure coincides with the central axis of the rotary support structure.

[0017] Furthermore, it also includes a support rod, which is located on the same plane as the waveguide support structure; one end of the support rod is connected to the waveguide support structure, and the other end is connected to the connecting waveguide through the waveguide support structure to support the connecting waveguide.

[0018] Furthermore, the waveguide support structure consists of a matching lug 101, a waveguide block 102, a circular retaining plate 104, and a felt strip 103. The waveguide block 102 is a cylinder with a limiting groove in the middle of its circumferential side, and a through square hole in the middle of the cylinder's central axis. The matching lug is connected to the limiting groove by bolts.

[0019] The waveguide support block 102 has a square hole in the middle with a felt strip 103 for connecting the connecting waveguide and for damping the connecting waveguide; two circular clips 104 are installed at both ends of the waveguide support block 102 to limit the felt strip 103 between the waveguide support block 102 and the connecting waveguide, and also to constrain the size of the opening in the middle of the waveguide support block 102.

[0020] Furthermore, the support rod is connected to the matching lug, and the two are an integral structure.

[0021] Furthermore, both the waveguide support block 102 and the circular plate 104 are cylindrical with a square hole in the middle through which the waveguide passes. They are both divided into two bodies diagonally through the square hole, and the cuts intersect each other during installation.

[0022] The beneficial effects of this invention are as follows: The mechanically rotating Ku-band orthogonal mode coupler and connecting waveguide of this invention enable fine-tuning of Ku-band polarization in C / Ku feed networks, extending the Ku-band output port beyond the feed mounting plate, thus facilitating the installation and replacement of Ku-band low-noise amplifiers. This invention is also applicable to dual-band and multi-band shared multi-horn feed antenna systems in Ku / Ka, X / Ku / Ka, and other frequency bands. Attached Figure Description

[0023] Figure 1 This is a structural schematic diagram of an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the upper surface structure of the lower support disk according to an embodiment of the present invention;

[0025] Figure 3 yes Figure 2 Side view;

[0026] Figure 4 This is a schematic diagram of the rotation drive chain structure according to an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the polarization angle sensitive structure according to an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the waveguide support structure of this invention patent;

[0029] Figure 7 This invention patent describes a method for mounting and assembling a motor and gears.

[0030] Figure 8 This is a motor and gear mounting method according to the present invention patent;

[0031] Figure 9 This is a limit switch combination method of the present invention patent.

[0032] In the diagram: 1. Orthogonal membrane coupler, 2. Waveguide rotary joint, 3. Rotary support structure, 4. Motor, 5. Driven gear one, 6, 7. Transmission gear, 8. Transmission shaft, 9. Driven gear two, 10. Waveguide support structure, 11. Connecting waveguide, 12. Limiting structure, 13. Lower support plate, 14. Upper support plate, 101. Matching lug, 102. Waveguide support block, 103. Felt strip, 104. Circular plate, 15. Motor mounting base, 16. Output gear. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings and examples. However, the embodiments described herein are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] A Ku-band polarization fine-tuning mechanism in a C / Ku feed network includes a motor, a drive shaft, a top plate, an orthogonal mode coupler 1, a rotary support structure 3, an upper support plate, and a lower support plate. The bottom end of the orthogonal mode coupler is connected to the upper surface of the upper support plate through the rotary support structure. The center of the upper support plate is located on the central axis of the orthogonal mode coupler, and the orthogonal mode coupler can rotate around its central axis.

[0035] The upper support plate has a first arc-shaped hole and an upper shaft hole. The top end of the orthogonal mode coupler is connected to the top plate bearing through a waveguide rotary joint. The lower support plate is located below the upper support plate. The lower support plate has a second arc-shaped hole and a lower shaft hole. A connecting waveguide connected to one side of the orthogonal mode coupler extends vertically downward, passing through the first arc-shaped hole of the upper support plate and the second arc-shaped hole of the lower support plate. The upper surface of the lower support plate is also provided with a waveguide support structure connected to its bearing. A driven gear is fixed on the outer wall of the waveguide support structure.

[0036] The motor is mounted on the lower support plate via a motor bracket, and the driving gear and driven gear on the motor drive shaft mesh together.

[0037] The top plate is also provided with a fixed shaft hole. The top end of the transmission shaft is connected to the fixed shaft hole bearing, and its bottom end passes through the upper shaft hole and is connected to the lower shaft hole bearing. Both the upper and lower halves of the transmission shaft are provided with transmission gears. A driven gear two is fixed on the outer wall of the rotating support structure. The transmission gear of the lower half of the transmission shaft is located on one side of the driven gear one and meshes with it. The transmission gear of the upper half of the transmission shaft and the driven gear two are located on the same plane, and the transmission gear and the driven gear two mesh with each other.

[0038] Furthermore, the drive shaft is connected to the upper shaft bore bearing.

[0039] Furthermore, the central axis of the waveguide support structure coincides with the central axis of the rotary support structure.

[0040] Furthermore, it also includes a support rod, which is located on the same plane as the waveguide support structure; one end of the support rod is connected to the waveguide support structure, and the other end is connected to the connecting waveguide through the waveguide support structure to support the connecting waveguide.

[0041] Furthermore, the waveguide support structure consists of a matching lug 101, a waveguide block 102, a circular retaining plate 104, and a felt strip 103. The waveguide block 102 is a cylinder with a limiting groove in the middle of its circumferential side, and a through square hole in the middle of the cylinder's central axis. The matching lug is connected to the limiting groove by bolts.

[0042] The waveguide support block 102 has a square hole in the middle with a felt strip 103 for connecting the connecting waveguide and for damping the connecting waveguide; two circular clips 104 are installed at both ends of the waveguide support block 102 to limit the felt strip 103 between the waveguide support block 102 and the connecting waveguide, and also to constrain the size of the opening in the middle of the waveguide support block 102.

[0043] Furthermore, the support rod is connected to the matching lug, and the two are an integral structure.

[0044] Furthermore, both the waveguide support block 102 and the circular plate 104 are cylindrical with a square hole in the middle through which the waveguide passes. They are both divided into two bodies diagonally through the square hole, and the cuts intersect each other during installation.

[0045] The following explanation is further illustrated with reference to the attached diagram:

[0046] As shown in Figure 1, Figure 2 As shown, this embodiment describes a Ku-band polarization fine-tuning mechanism in a C / Ku feed network. A DC motor 4 drives the Ku-band orthogonal mode coupler 1 and the connecting waveguide 11 in the feed network to rotate together, thereby rotating the Ku-band polarization relative to the C-band polarization by a certain angle. This corrects the polarization angle deviation of the C and Ku-band linear polarization states caused by the different Faraday rotation angles when electromagnetic waves of different frequency bands pass through the ionosphere.

[0047] like Figure 1 , Figure 2 , Figure 3 As shown, the connecting waveguide of the Ku-band orthogonal mode coupler 1 is a rectangular waveguide used to install a receiving low-noise amplifier. The connecting waveguide extends out from behind the feed network connection plate. After the feed network is installed on the antenna, the output port of the connecting waveguide and the connected low-noise amplifier are located in the center of the antenna body, making it easy to replace if the low-noise amplifier is damaged.

[0048] like Figure 3 , Figure 4 As shown, the Ku-band orthogonal mode coupler rotates synchronously with the connecting waveguide 11, and the Ku-band connecting waveguide 11 is fixed and supported by the matching lug 101 near the rear plate.

[0049] like Figure 4 , Figure 5 As shown, in this embodiment, when the Ku-band polarization fine-tuning mechanism adjusts the Ku-band polarization, the angle-sensitive element senses the rotation angle of the polarization. The angle-sensitive element mounting and rotation support structure 3 is fixed axially to the Ku-band orthogonal mode coupler 1 and the driven gear 9, and the other side is fixed to a structure that is stationary relative to the C-band waveguide device. The other end of the metal foil strip 33 fixed on the rotation axis of the angle-sensitive element is fixed to the driven gear 9. When the Ku-band polarization fine-tuning mechanism adjusts the change in the Ku-band polarization angle relative to the C-band polarization angle, the angle-sensitive element senses the rotation angle of the Ku-band polarization. The angle-sensitive element 34 and the angle-sensitive element mounting base 32 mounting and rotation support structure 3 are fixed axially to the Ku-band orthogonal mode coupler 1 and the driven gear 9, and the other side is fixed to the C-band waveguide device that is stationary relative to the C-band polarization. The other side of the coupling 33 fixed on the rotation axis of the angle-sensitive element is fixed between the driven gear 9 and the angle-sensitive element mounting base support shell 31.

[0050] like Figure 1 , Figure 4 , Figure 6 As shown, the waveguide support structure 10 of the Ku-band connecting waveguide in this embodiment rotates synchronously with the Ku orthogonal mode coupler 1.

[0051] like Figure 1 , Figure 2 , Figure 6 As shown, the waveguide support structure 10 of this embodiment consists of a cylindrical waveguide support block 102 with mounting cylindrical holes for matching lugs 101, a circular retaining plate 104, and a felt strip 103. The waveguide support block 102 is a relatively long cylinder with a limiting groove in the middle. The square hole in the middle can be adjusted in size for fixing and supporting the waveguide on the lugs for fixing and clamping. A felt strip 103 is placed between the waveguide support block 102 and the connecting waveguide. The retaining plate 104 is installed at both ends of the waveguide support block 102 to restrict the felt strip 103 between the waveguide support block 102 and the connecting waveguide, and can also fix the size of the opening in the middle of the waveguide support block 102. Both the waveguide support block 102 and the retaining plate 104 are cylinders with a square hole in the middle through which the waveguide passes. They are both cut into two parts diagonally through the square hole, and the cuts intersect each other during installation.

[0052] like Figures 1-4As shown, in this embodiment, the waveguide support structure 10 of the Ku-band connecting waveguide is fixed to the driven gear 5, and the Ku-band orthogonal mode coupler 1 is fixed to the driven gear 9. The driven gear 5 and the driven gear 9 are formed by splitting a single spur gear. The drive gear fixed on the motor shaft drives the driven gear 5, and the rotation is transmitted to the driven gear 9 through the transmission gear 6, the transmission gear 7, and the transmission shaft 8, so as to realize the synchronous rotation of the Ku-band connecting waveguide and the orthogonal mode coupler 1.

[0053] like Figure 1 , Figure 2 , Figure 6 and Figure 9 As shown, the waveguide support structure 10 of the Ku-band connecting waveguide described in this embodiment rotates synchronously with the Ku-band orthogonal mode coupler 1. The position rotation is limited by a limiting structure 12, and the limiting position can be adjusted.

[0054] like Figure 1 , Figure 2 As shown, in this embodiment, there is a waveguide rotary joint 2 between the Ku-band polarization fine-tuning mechanism and the C-band electrical structure.

[0055] like Figure 7 and Figure 8 The drive structure is shown in the figure, and rotation is achieved through a transmission structure.

Claims

1. A Ku-band polarization fine tuning mechanism in a C / Ku feed network comprising a motor, characterized in that, It also includes a transmission shaft, a top plate, a quadrature mode coupler (1), a rotating support structure (3), an upper support disc and a lower support disc; the bottom end of the quadrature mode coupler is connected to the upper surface of the upper support disc through the rotating support structure, the center of the upper support disc is located on the central axis of the quadrature mode coupler, and the quadrature mode coupler can rotate around the central axis; The upper support disc is provided with a first arc-shaped hole and an upper shaft hole, the top end of the quadrature mode coupler is connected to the top plate bearing through a waveguide rotary joint, the lower support disc is located below the upper support disc, the lower support disc is provided with a second arc-shaped hole and a lower shaft hole, and a connecting waveguide connected to one side of the quadrature mode coupler extends vertically downwards and passes through the first arc-shaped hole of the upper support disc and the second arc-shaped hole of the lower support disc; the upper surface of the lower support disc is also provided with a waveguide support structure connected to the lower support disc bearing; a driven gear one is fixedly arranged on the outer wall of the waveguide support structure; The motor is arranged on the lower support disc through a motor support, and a driving gear on a motor driving shaft is engaged with the driven gear one; The top plate is also provided with a fixed shaft hole, the top end of the transmission shaft is connected to the fixed shaft hole bearing, and the bottom end passes through the upper shaft hole and the lower shaft hole bearing; the upper half and the lower half of the transmission shaft are both provided with a transmission gear; a driven gear two is fixedly arranged on the outer wall of the rotating support structure; the transmission gear of the lower half of the transmission shaft is located on one side of the driven gear one and is engaged with the driven gear one; the transmission gear of the upper half of the transmission shaft and the driven gear two are located in the same plane, and the transmission gear and the driven gear two are engaged with each other.

2. The Ku-band polarization fine adjustment mechanism in a C / Ku feeder network according to claim 1, wherein, The transmission shaft is connected to the upper shaft hole bearing.

3. The Ku-band polarization fine tuning mechanism in a C / Ku feeder network according to claim 1, wherein, The central axis of the waveguide support structure coincides with the central axis of the rotating support structure.

4. The Ku-band polarization fine tuning mechanism in a C / Ku feeder network according to claim 1, wherein, It also includes a support rod, the support rod and the waveguide support structure are located in the same plane, one end of the support rod is connected to the waveguide support structure, and the other end is connected to the connecting waveguide through the waveguide support structure and is used for supporting the connecting waveguide.

5. The Ku-band polarization fine tuning mechanism in a C / Ku feeder network according to claim 4, wherein, The waveguide support structure is composed of a matching lug (101), a waveguide support block (102), a round sheet clamping plate (104) and a felt strip (103), the waveguide support block (102) is a cylinder, the middle of the circumferential surface is limited by a clamping groove, and a through middle square hole is arranged on the central axis of the cylinder; the matching lug is connected to the clamping groove through a bolt; The middle square hole of the waveguide support block (102) is provided with a felt strip (103) for connecting the connecting waveguide and damping the connecting waveguide; two round sheet clamping plates (104) are installed at both ends of the waveguide support block (102) and are used for limiting the felt strip (103) between the waveguide support block (102) and the connecting waveguide and for restricting the size of the middle opening of the waveguide support block (102).

6. The Ku-band polarization fine tuning mechanism in a C / Ku feeder network according to claim 5, wherein, The support rod is connected to the matching lug, and the two are an integral structure.

7. The Ku-band polarization fine tuning mechanism in a C / Ku feeder network according to claim 6, wherein, The waveguide support block (102) and the round sheet clamping plate (104) are both cylinders, the middle is a square hole through which the waveguide passes, and both are divided into two bodies through the square hole, and the cutting seams are staggered with each other during installation.

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