Distributed refrigeration waveguide polarization coupling device

Abstract

The invention relates to a distributed refrigeration waveguide polarization coupling device. The device comprises a window flange assembly, a window circular waveguide, a circular waveguide, a circular-square waveguide transition conversion piece, a phase shifter and an orthogonal coupler which are arranged in sequence, the window circular waveguide adopts a sectional waveguide and comprises a window circular waveguide upper half part and a window circular waveguide lower half part which are arranged at an interval; a window heat insulation support is arranged on the outer side of the window circular waveguide; the outer surface of the phase shifter and the outer surface of the orthogonal coupler are provided with a heat insulation supporting structure. According to the distributed refrigeration waveguide polarization coupling device, the integrated design of the sectional waveguide, the distributed heat insulation supporting module and the refrigeration module is adopted, the distributed refrigeration waveguide polarization coupling device can work below a liquid nitrogen temperature zone, thermal noise can be effectively reduced, and signal transmission loss can be reduced. The waveguide polarization coupling device is integrated with a heat insulation supporting structure, is small in size, is easy to assemble and debug, is stable in performance at low temperature, and can well meet the requirements of current related systems.

Description

Technical Field

[0001] The present invention relates to the field of microwave communication technology, and in particular to a distributed refrigeration waveguide polarization coupling device. Background Art

[0002] As a passive component at the front end of a radio receiver system, the waveguide polarization coupler is a crucial component. Radio astronomy uses large antennas to receive weak signals from distant radio sources. A band-specific feed is used at the focal plane to transmit the signal to the receiving system. The signal is then converted via a circular waveguide and a circular-to-square waveguide transition element to a phase shifter for orthogonal decomposition and phase processing, resulting in a circularly polarized signal output. Finally, an orthogonal mode coupler separates and outputs the orthogonal circularly polarized signals.

[0003] Existing polarizers or couplers are typically designed for room-temperature environments, using phase shifters and orthogonal mode couplers (OMTs) to separate or combine two orthogonally polarized signals. However, in cryogenic applications, these conventional devices have the following limitations: Waveguide systems operating at room temperature are susceptible to thermal noise in the microwave and millimeter-wave frequency bands, resulting in increased signal transmission loss. Furthermore, their complex structure, with the cooling module and polarization coupling structure separated, results in a bulky device that struggles to meet compactness requirements. Summary of the Invention

[0004] The purpose of the present invention is to provide a distributed refrigerated waveguide polarization coupling device for use in the microwave / millimeter wave frequency band. The device is particularly suitable for high-performance communication systems (such as satellite communications and radio astronomy observations) that require a low-temperature operating environment. By integrating distributed refrigeration technology with a polarization coupling structure, low-loss and high-efficiency polarization signal processing can be achieved.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A distributed refrigerated waveguide polarization coupling device comprises a window flange assembly, a window circular waveguide, a circular waveguide, a circular-square waveguide transition element, a phase shifter, and an orthogonal coupler, which are arranged in sequence. The window circular waveguide is a segmented waveguide, comprising an upper half of a window circular waveguide and a lower half of a window circular waveguide arranged at intervals. A window thermal insulation support is provided on the outer side of the window circular waveguide. A thermal insulation support structure is provided on the outer surfaces of the phase shifter and the orthogonal coupler.

[0007] Furthermore, the window flange assembly includes a window flange 1 and a window flange 2 arranged below the window flange 1.

[0008] Furthermore, the thermal insulation support structure includes a polarizer thermal insulation support 1 and a polarizer thermal insulation support 2 arranged outside the connection between the phase shifter and the orthogonal coupler, and a polarizer thermal insulation support 3 arranged outside the middle section of the orthogonal coupler.

[0009] Furthermore, the upper half of the window circular waveguide is connected to the upper end of the window insulation support and the flange assembly through screws; the lower half of the window circular waveguide is connected to the lower end of the window insulation support and the upper end of the circular waveguide through screws.

[0010] Furthermore, the gap between the upper half of the window circular waveguide and the lower half of the window circular waveguide is 0.2 mm.

[0011] Furthermore, a groove is provided on the top of the second window flange; the first window flange is installed in the groove; a sealing ring groove is provided in the groove, and a sealing rubber ring is installed in the sealing ring groove.

[0012] Furthermore, the polarizer thermal insulation support 1 adopts a clamp-type structure, which is divided into left and right halves, and is used to wrap around the periphery of the connection between the phase shifter and the orthogonal coupler; a first connecting plate is provided on the left half of the polarizer thermal insulation support 1, and a plurality of first connecting holes are provided on the first connecting plate.

[0013] Furthermore, the polarizer thermal insulation support 2 and the polarizer thermal insulation support 3 are both L-shaped structures, including a second connecting plate and a third connecting plate arranged on one side of one end of the second connecting plate; the second connecting plate and the third connecting plate are both provided with multiple second connecting holes.

[0014] Furthermore, the orthogonal mode coupler is a three-port microwave device in the form of a Boifot node.

[0015] Furthermore, the window thermal insulation support, the polarizer thermal insulation support 1, the polarizer thermal insulation support 2 and the polarizer thermal insulation support 3 are all made of G10 material.

[0016] Compared with the prior art, the advantages of the present invention are:

[0017] The distributed refrigerated waveguide polarization coupling device described in this invention utilizes an integrated design consisting of a segmented waveguide, a distributed thermal insulation support module, and a refrigeration module. This design allows for operation below the liquid nitrogen temperature range, effectively reducing thermal noise and signal transmission loss. Furthermore, the waveguide polarization coupling device, with its integrated thermal insulation support structure, is compact and easy to assemble and debug, while offering stable performance at low temperatures, effectively meeting the requirements of current related systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a front view of the distributed cooling waveguide polarization coupling device of the present invention;

[0019] Figure 2 It is a structural diagram of the window flange assembly, the window circular waveguide, and the window thermal insulation support;

[0020] Figure 3 This is a schematic diagram of the structure of the polarizer thermal insulation support one;

[0021] Figure 4 This is a schematic diagram of the structure of the polarizer thermal insulation support 2;

[0022] Figure 5 This is a schematic diagram of the structure of the polarizer thermal insulation support three;

[0023] Figure 6 Schematic diagram of the structure of window flange 1 and window flange 2 Figure 1 ;

[0024] Figure 7 Schematic diagram of the structure of window flange 1 and window flange 2 Figure 2 ;

[0025] Figure 8 This is a curve diagram of simulated input reflection loss parameters of the distributed cooling waveguide polarization coupling device of the present invention;

[0026] Figure 9 This is a curve diagram of simulated insertion loss parameters of the distributed cooling waveguide polarization coupling device of the present invention;

[0027] Figure 10 This is a curve diagram of the output port isolation parameter of the distributed refrigeration waveguide polarization coupling device in the present invention.

[0028] in:

[0029] 1. Window flange 1, 2. Window flange 2, 3. Window thermal insulation support, 4. Circular waveguide, 5. Circular-square waveguide transition component, 6. Phase shifter, 7. Polarizer thermal insulation support 1, 8. Polarizer thermal insulation support 2, 9. Polarizer thermal insulation support 3, 10. Orthogonal mode coupler, 11. Sealing ring groove, 12. Upper half of window circular waveguide, 13. Lower half of window circular waveguide. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings:

[0031] like Figure 1The distributed refrigerated waveguide polarization coupling device shown in FIG. comprises, arranged from top to bottom, a window flange assembly, a window circular waveguide, a circular waveguide 4, a circular-to-square waveguide transition element 5, a phase shifter 6, and an orthogonal coupler 10. Thermal insulation support structures are provided on the exterior of the phase shifter 6 and the orthogonal coupler 10. A window thermal insulation support 3 is sheathed on the exterior of the window circular waveguide. The window flange assembly comprises window flange 1 and window flange 2. These components are secured together using screws.

[0032] The above-mentioned distributed refrigeration waveguide polarization coupling device is designed to work below the liquid nitrogen temperature zone and is fixed on the inner wall of the Dewar. After converting the input arbitrary polarization signal into a circularly polarized signal, it separates and outputs the left and right rotating signals. The device has the characteristics of broadband, compact structure and stability. The above-mentioned distributed refrigeration waveguide polarization coupling device has two innovations. One is that the front end of the waveguide polarization coupling device is designed to be a window circular waveguide and a window insulation support that can adapt to low-temperature applications and perform multi-section waveguide insulation, which can achieve effective signal transmission from room temperature to low temperature; the other is that by setting up an insulation support structure, an integrated design of the insulation support structure, the distributed refrigeration module and the waveguide structure is realized, thereby achieving compact and uniform low-temperature control. There is a contradiction between the demand for low-temperature refrigeration and the compactness of the structure in the existing technology. The present invention integrates the refrigeration module into the gap of the waveguide structure through the topological optimization of the insulation support structure, breaking through the stereotype that refrigeration must be huge.

[0033] In some embodiments, the input end of the polarization coupling device uses a window circular waveguide for thermal insulation transmission, such as Figure 2 As shown, the window circular waveguide is a segmented waveguide, comprising an upper window circular waveguide portion and a lower window circular waveguide portion, with a gap between the two waveguide portions, preventing direct contact. In this embodiment, a window thermal insulation support 3 is used to connect the upper window circular waveguide portion 12 and the lower window circular waveguide portion 13, with a certain gap distance between the upper and lower window circular waveguide portions. The window thermal insulation support 3 is used to connect the upper and lower waveguide portions and maintain the gap distance between the two waveguide portions.

[0034] In some embodiments, the input end of the polarization coupling device is thermally insulated and sealed using a window flange assembly. Figure 2 As shown, the window flange 1 and the window flange 2 are connected by screws. Figure 6 and Figure 7 As shown, the top of the window flange 2 is provided with a groove, and the bottom of the window flange 1 is embedded in the groove. The height of the groove is 2.5mm. This design can achieve a tight connection between the two window flanges while preventing signal leakage and interference.

[0035] In some embodiments, a sealing ring groove 11 with a width of 2 mm is provided at a certain distance from the inner wall of the window flange 2. A sealing rubber ring is installed in the sealing ring groove 11. The sealing rubber ring is located between the window flange 1 and the window flange 2 to prevent external normal temperature gas from leaking into the internal low-temperature vacuum environment under the action of atmospheric pressure.

[0036] Furthermore, the window circular waveguide, i.e., the circular waveguide of the window portion of the polarization coupling device, is divided into two parts, an upper window circular waveguide portion 12 and a lower window circular waveguide portion 13, arranged from top to bottom. The two parts are not in direct contact, and there is a 0.2mm gap between them to prevent heat loss caused by direct heat conduction from the metal. Considering that the thermal conductivity of air at room temperature is only 0.023W / (m·K), the present invention uses the 0.2mm gap design between the upper window circular waveguide portion 12 and the lower window circular waveguide portion 13 to block direct heat conduction from the metal by utilizing the thermal resistance of the air layer. At the same time, the G10 material (thermal conductivity 0.3W / (m·K), which is only 1 / 500 of that of aluminum alloy) of the window insulation support 3 further reduces the heat conduction efficiency. Compared with the traditional integral waveguide, the segmented design of the window circular waveguide significantly reduces the heat loss in the temperature zone transition section.

[0037] In some embodiments, the window insulation support 3 is connected to the upper and lower parts of the window circular waveguide. Figure 2 As shown, screws are used to connect the upper half 12 of the window circular waveguide to the upper end of the window insulation support 3 and the flange assembly. Screws are also used to connect the lower half 13 of the window circular waveguide to the lower end of the window insulation support 3 and the upper end of the circular waveguide 4. The window insulation support 3 is used to maintain the height of the gap between the upper and lower halves of the window circular waveguide and to prevent heat transfer between the window and the refrigeration device. The window insulation support 3 is provided with multiple through-holes.

[0038] In the distributed cooling waveguide polarization coupling device described in the present invention, the window flange 1 and the window flange 2 2 are in direct contact with the normal temperature environment, and the other components are in a low-temperature environment. Therefore, the window thermal insulation support 3 becomes an important temperature transition component. By processing many circular holes on the window thermal insulation support 3, the area of ​​the window cylindrical thermal insulation support can be reduced. The important factor in the thermal radiation calculation formula is the surface area. Reducing the surface area of ​​the device reduces thermal radiation, reduces the loss of cold in the low-temperature environment, and is conducive to cooling and maintaining the low-temperature environment. In addition, since G10 material inevitably generates internal bubbles during processing, an important step for the Dewar before cooling is vacuuming. The multiple circular through holes staggered on the window thermal insulation support 3 will not only not reduce the support degree, but also reduce bubbles and reduce gas overflow during the vacuuming stage.

[0039] In some embodiments, the circular-square waveguide transition conversion element 5 is used to convert the signal input from the window circular waveguide into a square waveguide (the inside of the phase shifter 6 is a square waveguide), and the smooth structure is used to avoid the occurrence of discontinuous structures inside the polarization coupling device, which may cause signal mutations.

[0040] In some embodiments, the phase shifter 6 adopts a double-ridge structure to change the transmission environment of the square waveguide. When the length remains unchanged, the phase shifter 6 causes two orthogonal linear polarization signals to have a 90-degree phase difference, completing the conversion from linear polarization to circular polarization.

[0041] In some embodiments, the connector at the output end of the polarization coupling device is in the form of one or more of a rectangular waveguide, an SMA connector, and an N connector. The planes where the two output ports of the polarization coupling device are located are perpendicular to each other.

[0042] In some embodiments, the phase shifter 6 and orthogonal mode coupler 10 are integrated with an insulating support structure on their outer surfaces, which is connected to the cooling module via the insulating support structure. The insulating support structure includes polarizer insulating support 1 7, polarizer insulating support 2 8, and polarizer insulating support 3 9. The cooling module is conventional. The cooling module is integrated with the waveguide structure through the window insulating support 3 and three polarizer insulating supports, achieving a three-in-one design of support, cooling, and signal transmission, significantly reducing the device size.

[0043] Specifically, polarizer thermal insulation support 1 7 and polarizer thermal insulation support 2 8 are provided at the connection between the phase shifter 6 and the orthogonal mode coupler 10. The polarizer thermal insulation support 1 7 and polarizer thermal insulation support 2 8, on the one hand, serve as the mounting structure of the distributed refrigeration module, and on the other hand, are used for heat conduction to reduce the entire polarization coupling device to the required operating temperature (20K, i.e. -253 degrees Celsius). Polarizer thermal insulation support 3 9 is provided on the outer side of the middle and lower sections of the orthogonal coupler 10. Polarizer thermal insulation support 1 7, polarizer thermal insulation support 2 8 and polarizer thermal insulation support 3 9 can make the phase shifter and the orthogonal mode coupler be connected firmly. Avoid tilting, thereby affecting the electrical performance. As Figure 3 As shown, the polarizer thermal insulation support 7 utilizes a clamp-type structure, divided into left and right halves connected by screws or bolts. It is designed to wrap around the periphery of the connection between the phase shifter 6 and the orthogonal coupler 10. A first connecting plate is provided on the left half of the polarizer thermal insulation support 7, with multiple first connecting holes defined on the first connecting plate. Because the entire polarization coupling device is relatively long and is installed in the dewar cavity, connecting to the feed horn only through a window on one side of the dewar, it may tilt during use. Therefore, a first connecting plate is provided to secure it to the side wall of the dewar.

[0044] Further, such as Figure 4 and Figure 5As shown, both the second polarizer insulation support 8 and the third polarizer insulation support 9 are L-shaped structures, including a second connecting plate and a third connecting plate disposed on one side of one end of the second connecting plate. Both the second and third connecting plates are provided with multiple second connecting holes. The second connecting plate of the second polarizer insulation support 8 is removably mounted on the outer wall of the right half of the polarizer insulation support 7. The polarizer insulation support 7 adopts a clamping structure because directly mounting the L-shaped fixing plate on the device with screws may cause device deformation, which has a significant impact on microwave waveguide devices and can cause misalignment at the device connection, all of which will affect performance. Using a clamping polarizer insulation support 7, on the other hand, does not interfere with the original device structure and can also provide a tightening effect. The clamping polarizer insulation support 7 is used to add a fixing position to the device. The L-plate polarizer insulation support 2 8 connects the clamping polarizer insulation support 7 to the side wall of the dewar. Through the standardized interface design of the clamp-type polarizer insulation support 7 and the L-shaped polarizer insulation support 2 8 and polarizer insulation support 3 9, modular rapid assembly is achieved, the assembly time is greatly shortened, and the structural deformation at low temperature (20K) can be effectively controlled.

[0045] In some embodiments, the orthogonal-mode coupler 10 is a three-port microwave device employing a Boifot junction as known in the art. Input signals enter the input port of the orthogonal-mode coupler in mutually orthogonal linear polarization modes. After polarization separation by the orthogonal-mode coupler 10, two mutually orthogonal left-handed and right-handed polarization signals are output.

[0046] In some embodiments, the window flange 1, window flange 2, circular waveguide 4, circular-square waveguide transition conversion component 5, phase shifter 6, orthogonal mode coupler 10, window circular waveguide upper part 12, and window circular waveguide lower part 13 are all made of aluminum alloy 6061-T6 material, and the surfaces of the components are not painted.

[0047] In some embodiments, the window insulation support 3, the polarizer insulation support 1 7, the polarizer insulation support 2 8 and the polarizer insulation support 3 9 are all made of G10 material. By combining the segmented waveguide with the G10 insulation material, such as Figure 9 As shown, the insertion loss of the device in the 20K temperature range can be minimized, and the thermal noise suppression effect is greatly improved.

[0048] Figure 8 This is a curve diagram of the simulated input reflection loss parameters of the distributed cooling waveguide polarization coupling device in the present invention, where the horizontal axis is the frequency range of 12GHz-18GHz, and the vertical axis is the electromagnetic simulation S11 parameter, that is, the reflection loss, in dB. Figure 8 The two curves in the middle represent two modes in which the input terminals are set to be orthogonal to each other. Figure 8It can be seen that the reflection loss in the range of 12-18G meets the usage requirements.

[0049] Figure 9 This is a curve diagram of the simulated insertion loss parameters of the distributed cooling waveguide polarization coupling device in the present invention, wherein the horizontal axis is the frequency range of 12GHz-18GHz, and the vertical axis is the electromagnetic simulation parameter S21 parameter, that is, the insertion loss, in dB. Figure 9 The two curves in the middle represent two modes in which the input port is set to be orthogonal to each other, indicating the loss value of the signal transmitted from the input port to the output port. Figure 9 It can be seen that the loss meets the usage requirements within the required range.

[0050] Figure 10 This is a curve diagram of the output port isolation parameter of the distributed cooling waveguide polarization coupling device in the present invention. Among them, the horizontal axis is the frequency range of 12GHz-18GHz, and the vertical axis is the electromagnetic simulation parameter S21 parameter, which also belongs to the insertion loss. However, the signal does not enter from the input port, but from one of the output ports, and detects the power of the signal at another mutually orthogonal port, that is, the isolation. Figure 10 It can be seen that the isolation between the two output ports meets the usage requirements.

[0051] In summary, the waveguide polarization coupling device described in the present invention serves as a key component in radio astronomy cryogenic receiver systems, used for signal polarization conversion and polarization separation in cryogenic operating environments. By adjusting the waveguide dimensions, it can operate in different frequency bands. The waveguide polarization coupling device is placed within a cryogenic dewar and connected to the feed horn via a circular waveguide window. To ensure a secure connection and prevent tilting that could affect electrical performance, polarizer thermal insulation supports 2 and 3 9 are designed on the orthogonal mode coupler 10. Each component of the device is separately machined and connected via flanges, making it easy to manufacture, assemble, and debug, while maintaining a stable and reliable structure. The waveguide polarization coupling device utilizes a window flange and a segmented waveguide thermal insulation seal at its input, while its output utilizes an integrated distributed refrigeration module. This device can operate below the liquid nitrogen temperature range, effectively reducing thermal noise and signal transmission loss. Furthermore, the waveguide polarization coupling device integrates an integrated thermal insulation support structure, making it compact, easy to assemble, and debug, and offering stable performance at low temperatures, effectively meeting the requirements of current related systems.

[0052] The above-described embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A distributed refrigeration waveguide polarization coupling device, characterized in that: The device comprises a window flange assembly, a window circular waveguide, a circular waveguide (4), a circular-square waveguide transition conversion element (5), a phase shifter (6) and an orthogonal coupler (10) which are arranged in sequence; the window circular waveguide adopts a segmented waveguide, comprising an upper half portion (12) of the window circular waveguide and a lower half portion (13) of the window circular waveguide which are arranged at intervals; a window heat insulation support (3) is arranged on the outer side of the window circular waveguide; and a heat insulation support structure is provided on the outer surfaces of the phase shifter (6) and the orthogonal coupler (10).

2. The distributed refrigeration waveguide polarization coupling device according to claim 1, characterized in that: The window flange assembly comprises a window flange 1 (1) and a window flange 2 (2) arranged below the window flange 1 (1).

3. The distributed cooling waveguide polarization coupling device according to claim 1, characterized in that: The thermal insulation support structure includes a polarizer thermal insulation support 1 (7) and a polarizer thermal insulation support 2 (8) arranged outside the connection between the phase shifter (6) and the orthogonal coupler (10), and a polarizer thermal insulation support 3 (9) arranged outside the middle section of the orthogonal coupler (10).

4. The distributed refrigeration waveguide polarization coupling device according to claim 1, characterized in that: The upper half (12) of the window circular waveguide is connected to the upper end of the window heat insulation support (3) and the flange assembly through screws; the lower half (13) of the window circular waveguide is connected to the lower end of the window heat insulation support (3) and the upper end of the circular waveguide (4) through screws.

5. The distributed cooling waveguide polarization coupling device according to claim 1 or 4, characterized in that: The gap between the upper half (12) of the window circular waveguide and the lower half (13) of the window circular waveguide is 0.2 mm.

6. The distributed cooling waveguide polarization coupling device according to claim 2, characterized in that: The top of the second window flange (2) is provided with a groove; the first window flange (1) is installed in the groove; a sealing ring groove (11) is provided in the groove, and a sealing rubber ring is installed in the sealing ring groove (11).

7. The distributed cooling waveguide polarization coupling device according to claim 3, characterized in that: The polarizer thermal insulation support (7) adopts a clamp-type structure and is divided into left and right halves, which are used to wrap around the periphery of the connection between the phase shifter (6) and the orthogonal coupler (10); a first connecting plate is provided on the left half of the polarizer thermal insulation support (7), and a plurality of first connecting holes are provided on the first connecting plate.

8. The distributed cooling waveguide polarization coupling device according to claim 7, characterized in that: The polarizer thermal insulation support 2 (8) and the polarizer thermal insulation support 3 (9) are both L-shaped structures, including a second connecting plate and a third connecting plate arranged on one side of one end of the second connecting plate; the second connecting plate and the third connecting plate are both provided with a plurality of second connecting holes.

9. The distributed refrigeration waveguide polarization coupling device according to claim 1, characterized in that: The orthogonal mode coupler (10) is a three-port microwave device in the form of a Boifot node.

10. The distributed cooling waveguide polarization coupling device according to claim 3, characterized in that: The window thermal insulation support (3), the polarizer thermal insulation support one (7), the polarizer thermal insulation support two (8) and the polarizer thermal insulation support three (9) are all made of G10 material.

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