Dual-polarized low-temperature compact receive front-end device capable of fast phase adjustment

Abstract

The application relates to a dual-polarized low-temperature compact receiving front-end device capable of realizing rapid phase adjustment, which comprises a vacuum sealing window, a heat insulation waveguide, a polarization network, a waveguide coupler, a low-temperature isolator, a low-temperature amplifier and a vacuum refrigeration system. The vacuum refrigeration system comprises a cold head, a cold plate, an expander, a vacuum Dewar and a cold screen. Different electromagnetic wave transmission forms are adopted to form dual-polarized signals, the signals are transmitted to a rectangular waveguide form, the rectangular waveguide transmission distance difference is utilized, a rectangular waveguide diaphragm is added for the adjustment of the phase difference of the dual-polarized signals, the waveguide coupler and the polarizer are only needed to be disassembled, the waveguide diaphragm with the corresponding thickness is added, and the screw is fixed back, so that the adjustment of the phase difference between the dual-polarized signals can be rapidly and effectively realized, other electrical performances are not affected, and the original assembly relationship is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of cryogenic electronic devices and cryogenic receiving systems, and in particular to a dual-polarization cryogenic compact receiving front-end device capable of realizing rapid phase adjustment. Background Art

[0002] The cooled receive front end (RXF) is a receiving unit operating in the liquid nitrogen and liquid helium temperature ranges. The liquid nitrogen temperature range primarily corresponds to the 77K operating temperature of superconducting systems, while the liquid nitrogen temperature range corresponds to the 4K operating temperature of quantum computer systems. Its function is to read and transmit weak signals, such as deep-space signals or quantum bit signals. RXFs are important receiving equipment for large-aperture distributed receiving systems, deep-space exploration, and radio astronomy. These devices rely on circularly polarized antennas for both reception and transmission, and the received signal processing path is non-directional. After the circularly polarized signal enters the RXF, it undergoes a polarization network to convert it into a left-handed and right-handed polarization signal, allowing it to be processed by the receive channel. Therefore, the RXF device must have dual-polarization reception capabilities and ensure phase and amplitude consistency of the received electromagnetic wave signals.

[0003] Because differences in electromagnetic wave signal phase and amplitude significantly reduce the efficiency of multi-channel synthesis, thus weakening the detection capabilities of receiver systems, a practical phase adjustment device is essential. The cooling and warming time of a refrigerated receiver front end often exceeds four hours. The ability to quickly and accurately adjust the phase between channels after warming without causing changes in other system performance, mismatches, or changes in the original assembly relationship is crucial, as time is extremely valuable for both deep space exploration and target identification in military receiver systems. Summary of the Invention

[0004] In order to address the deficiencies in the prior art, the present invention aims to provide a dual-polarization low-temperature compact receiving front-end device capable of achieving rapid phase adjustment.

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

[0006] A dual-polarization, low-temperature, compact receiving front-end device capable of rapid phase adjustment includes a vacuum-sealed window, a thermally insulating waveguide, a polarization network, a waveguide coupler, a cryogenic isolator, a cryogenic amplifier, and a vacuum refrigeration system. The vacuum refrigeration system includes a cold head, a cold plate, an expander, a vacuum dewar, and a cold shield.

[0007] The cold head, cold plate, polarization network, waveguide coupler, low-temperature isolator and low-temperature amplifier are all located in the cold shield; the cold shield is located in the vacuum dewar; the vacuum sealing window is installed on the vacuum dewar; one end of the thermal insulation waveguide is connected to the vacuum sealing window, and the other end is connected to the cold shield.

[0008] The cold plate is installed on the cold head, and the low-temperature amplifier, waveguide coupler and low-temperature isolator are all installed on the cold plate; the expander is located outside the vacuum dewar, and is used to provide cooling for the cold head; the vacuum sealing window is installed on the vacuum dewar, and the thermal insulation waveguide is installed on the vacuum sealing window and is located inside the vacuum dewar, one end of the thermal insulation waveguide is connected to the vacuum sealing window, and the other end is connected to the cold screen; the input interface of the polarization network is connected to the cold screen, and the output interface of the polarization network is connected to the input interface of the waveguide coupler; the output interface of the waveguide coupler is connected to the input interface of the low-temperature isolator, and the output interface of the low-temperature isolator is connected to the input interface of the low-temperature amplifier.

[0009] The thermally isolated waveguide transmits the signal to the polarization network, which dual-polarizes the signal into two output paths. The output interface of the polarization network uses a rectangular waveguide interface. Phase adjustment of the device is achieved by disposing rectangular waveguide membranes between the output interface of the polarization network and the input interface of the waveguide coupler. The thickness and number of rectangular waveguide membranes are adjusted. The number of rectangular waveguide membranes is greater than or equal to 0.

[0010] According to a preferred embodiment of the present invention, the vacuum Dewar is made of aluminum and is polished to reduce cold radiation under vacuum.

[0011] Preferably, according to the present invention, the cold shield is used to isolate the cooling capacity of the cold head, and the cold shield is made of aluminum that is nickel-plated and then polished.

[0012] Preferably, according to the present invention, the cold plate is U-shaped and fixed to the cold head 9 by screws; the low-temperature amplifier and the low-temperature isolator are cooled to below 10K by the action of the cold plate.

[0013] Preferably, according to the present invention, the vacuum sealing window is a metal structure processed by aluminum gold plating process, which is in the working temperature range of 300K, and the vacuum sealing window realizes wave transmission through the sealing film.

[0014] Preferably, according to the present invention, the thermal insulation waveguide is a metal structure made of glass fiber material G10 and prepared by a metal copper gold plating process and polished; the thermal insulation waveguide is used to physically isolate the 10K cold plate and polarization network to 300K; the thermal insulation waveguide is provided with a weight-reducing circular hole.

[0015] Preferably, according to the present invention, the cold head and the cold plate are both made of copper with gold plating process and are polished.

[0016] Preferably, according to the present invention, the waveguide coupler is connected to the output interface of the polarization network via a screw; the output interface of the waveguide coupler is connected to the input interface of the cryogenic isolator via a coaxial cable; and the output interface of the cryogenic isolator is connected to the input interface of the cryogenic amplifier.

[0017] Preferably, according to the present invention, the vacuum sealing window and the thermal insulation waveguide adopt a circular waveguide transmission form; the input interface of the polarization network is a circular waveguide interface, and the output interface is a rectangular waveguide interface; the input interface of the waveguide coupler is a rectangular waveguide interface, and the output interface is a coaxial SMA interface; the low-temperature isolator and the low-temperature amplifier adopt a coaxial transmission form, and both have a radio frequency circuit composed of a microstrip printed circuit board and devices.

[0018] Preferably, according to the present invention, the circular waveguide interface and the rectangular waveguide interface are fixed with screws.

[0019] Compared with the prior art, the advantages of the present invention are:

[0020] (1) The dual-polarization low-temperature compact receiving front-end device capable of realizing rapid phase adjustment described in the present invention is used to realize electromagnetic wave signal reception of the dual-polarization low-temperature receiving front-end. The present invention adopts different transmission forms of electromagnetic waves to form dual-polarization signals, and a rectangular waveguide structure is provided on the signal transmission route, which can not only realize low-loss transmission of the waveguide coupler, but also add a rectangular waveguide diaphragm to achieve phase compensation for the adjustment of the phase difference of the dual-polarization signal. It is only necessary to disassemble the waveguide coupler and the polarizer, add a waveguide diaphragm of corresponding thickness, and fix it back with screws to quickly and effectively adjust the phase difference between the dual-polarization signals without affecting other electrical properties and ensuring the original assembly relationship. The advantages of this technology are that the waveguide circuit has much smaller loss than the microstrip circuit; the waveguide circuit has high processing accuracy; the waveguide circuit is assembled in a screw-mounted form, and the microstrip is assembled in a welding form, and the assembly relationship and structural form are simple. In summary, the advantage of this invention is that it can quickly adjust the phase without changing the original assembly relationship in a refrigerated environment and under fixed structural conditions.

[0021] (2) The dual-polarization low-temperature compact receiving front-end device capable of rapid phase adjustment described in the present invention can adjust and compensate for the phase difference between channels, has the characteristics of rapid phase adjustment, and does not affect other performances. The metal material of the rectangular waveguide interface is stable at low temperatures, and the rectangular waveguide only has TE or TM mode in the electromagnetic wave transmission mode, and does not produce mode changes due to length changes. During circuit transmission simulation, the receiving signal transmission mode can be changed to rectangular waveguide transmission. And by adding an adjustable surface, according to the phase size, the phase adjustment between the two channels of the dual-polarization receiving front end is achieved by adding a rectangular waveguide diaphragm, making low-temperature phase adjustment feasible, fast and without affecting other electrical performance indicators. The structure is compact and does not change the original assembly relationship. This design not only overcomes the change in electromagnetic wave transmission mode caused by circular waveguide adjustment, which causes system recognition signal errors, but also solves the disadvantages of adjustment uncertainty, instability, and low processing and manufacturing cycle and precision caused by low temperature changes of microstrip lines and transmission coaxial lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the structure of the dual-polarization low-temperature compact receiving front-end device capable of achieving rapid phase adjustment in the present invention;

[0023] Figure 2 This is a waveguide connection diagram of a dual-polarization, low-temperature, compact receiving front-end device capable of achieving rapid phase adjustment in the present invention;

[0024] Figure 3 It is a schematic structural diagram of the rectangular waveguide diaphragm in the present invention;

[0025] Figure 4 This is an example diagram of the phase compensation calculation of the rectangular waveguide diaphragm in the present invention.

[0026] in:

[0027] 1. Cold plate, 2. Cryogenic amplifier, 3. Cold shield, 4. Vacuum dewar, 5. Screws, 6. Waveguide coupler, 7. Expander, 8. Cryogenic isolator, 9. Cold head, 10. Insulated waveguide, 11. Vacuum microwave window, 12. Polarization network, 13. Waveguide diaphragm, 14. Waveguide-free diaphragm. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings:

[0029] Cryogenic receivers operate in temperatures below 10K. After receiving RF signals, they implement dual-polarization transmission through a polarization network. The output signals from the polarization network exhibit phase and amplitude differences, particularly phase differences. These discrepancies are then fed into a cryogenic amplifier for amplification and transmission to the terminal. This phase difference significantly reduces the efficiency of noise synthesis between dual channels and across multiple receiving front-end devices. The phase of electromagnetic signals is closely related to their transmission length. Electromagnetic wave transmission technology can utilize circular waveguides, rectangular waveguides, coaxial cables, and microstrip lines. However, due to the material and machining precision of coaxial and microstrip lines, adjusting the phase by increasing their length can cause significant fluctuations in amplitude and other parameters. This also requires welding and assembly, which alters the original assembly relationship, significantly increasing phase adjustment uncertainty. Circular waveguide transmission offers low loss, but the electromagnetic waves it transmits exhibit TE11, TH11, and higher-order modes. Increasing the transmission length introduces uncertainty.

[0030] In devices such as dual-polarization cryogenic receiving front-ends and multi-channel cryogenic receiving front-ends for distributed receiving systems, in order to solve the phase adjustment problem of two channels or multi-channel cryogenic receiving front-ends, so as to achieve fast phase adjustment without affecting other system indicators, especially multi-channel synthesis consistency, the present invention provides a method such as Figure 1-Figure 2 The device is a compact, low-temperature dual-polarization receiver front-end device capable of rapid phase adjustment. This device allows for rapid and efficient phase adjustment of the dual-polarization receiver front-end without compromising performance. The present invention utilizes a rectangular waveguide transition signal transmission interface and incorporates a rectangular waveguide diaphragm for phase compensation. The rectangular waveguide diaphragm exhibits stable metallic properties at low temperatures, low transmission loss, and excellent standing wave performance, resulting in high adjustment precision and accuracy without affecting other electrical properties of the circuit. Furthermore, the device utilizes screw fastening for compact assembly, maintaining the original state, ensuring guaranteed operation time and operability.

[0031] like Figure 1 The dual-polarization, low-temperature, compact receiving front-end device capable of rapid phase adjustment is shown. It includes a vacuum-sealed window 11, an insulating waveguide 10, a polarization network 12, a waveguide coupler 6, a cryogenic isolator 8, a cryogenic amplifier 2, and a vacuum refrigeration system. These components, such as the vacuum microwave window 11, the insulating waveguide 10, the polarization network 12, the waveguide coupler 6, the cryogenic isolator 8, and the cryogenic amplifier 2, are secured to a cold plate 1 via cold tape and cooled by the vacuum refrigeration system.

[0032] The vacuum refrigeration system includes a cold head 9, a U-shaped cold plate 1, an expander 7, a vacuum dewar 4, and a cold shield 3. The vacuum dewar 4 is made of polished aluminum to reduce cold radiation under vacuum. The cold shield 3 is nickel-plated and polished aluminum. It isolates the cold energy from the cold head 9 to ensure stable cooling. The expander 7 cools the cold head 9. The U-shaped cold plate 1 is fixed to the cold head 9 with screws 5. The cryoamplifier 2 and cryoisolator 8 are fixed to the U-shaped cold plate 1. The cold plate cools the cold head to below 10K.

[0033] Preferably, according to the present invention, the vacuum sealing window 11 is a metal structure processed by aluminum gold plating process, which is in the working temperature range of 300K. The vacuum sealing window 11 realizes wave transmission through the sealing film. The thermal insulation waveguide 10 is a metal structure processed by metal copper gold plating process and polishing. The thermal insulation waveguide 10 is used to physically isolate the 10K cold plate 9 and the polarization network 12 to 300K. The thermal insulation waveguide 10 is made of glass fiber material G10, and usually needs to add circular holes to reduce weight. The thermal insulation waveguide 10 is fixed to the vacuum sealing window 11. The cold head 9 and the cold plate 1 both adopt the copper gold plating process and are polished.

[0034] According to the preferred embodiment of the present invention, the thermal insulation waveguide 10 transmits the signal to the polarization network 12, and the polarization network 12 performs dual polarization on the signal into two outputs. The output interface of the polarization network 12 is as follows: Figure 2 As shown, it is a rectangular waveguide interface form. The waveguide coupler 6 is connected to the output interface of the polarization network 12 by screws. The output of the waveguide coupler 6 can be connected to the low-temperature isolator 8 through a coaxial cable, and the low-temperature isolator 8 is connected to the low-temperature amplifier 2. The vacuum sealing window 11 and the thermal insulation waveguide 10 are circular waveguide transmission forms. The input interface of the polarization network 12 is a circular waveguide port, and the output interface is designed as a rectangular waveguide port. The input of the waveguide coupler 6 is a rectangular waveguide interface, and the output is a coaxial SMA interface. The low-temperature isolator 8 and the low-temperature amplifier 2 are coaxial transmission forms, and the inside of the two is a radio frequency circuit composed of a microstrip printed circuit board and devices.

[0035] From the above content, it can be seen that the signal transmission passes through several transmission paths such as circular waveguide-rectangular waveguide-coaxial SMA-microstrip printed circuit board. Except for circular waveguide and rectangular waveguide, other forms of transmission signals are connected by cables and printed circuit boards and devices are connected by gold wires, which cannot be quickly replaced. The circular waveguide and rectangular waveguide are fixed with screws, which are easy to disassemble and replace. The present invention is a compact device that can adjust and compensate for the phase difference between dual polarization channels at low temperatures without changing the original assembly relationship. Moreover, the present invention is based on the metal copper rectangular waveguide transmission structure, which is stable at low temperatures and has a fixed transmission mode, low loss, and good standing wave, which can make low-temperature phase adjustment feasible and fast without affecting other electrical performance indicators.

[0036] like Figure 3As shown, the present invention is used to adjust the phase of the device by designing a rectangular waveguide membrane 13 with the same length and width as the rectangular waveguide interface and whose thickness can be adjusted according to the phase requirements. By setting multiple rectangular waveguide membranes 13, different phase adjustment needs can be met. Figure 3 In the figure, position 13 indicates the presence of a rectangular waveguide diaphragm, and position 14 indicates the absence of a waveguide diaphragm. The number of rectangular waveguide diaphragms is determined based on the phase difference between the channels. This allows for both small and large-scale phase adjustment of the microwave signal. By fixing the rectangular waveguide diaphragm between the waveguide coupler 6 and the output port of the polarization network 12, phase adjustment can be quickly achieved while maintaining the original assembly relationship. The rectangular waveguide diaphragm is copper-gold-plated, resulting in low transmission loss and good standing wave performance. Its addition does not affect the system's gain, standing wave, or other indicators, while achieving phase adjustment due to its increased thickness.

[0037] Figure 4 This is an example diagram of the phase compensation calculation of the rectangular waveguide diaphragm in the present invention. Figure 4 In the figure, the horizontal axis represents different frequencies in GHz; the vertical axis represents the phase value at different frequencies in degrees. Comparing the two curves, we can see that when the thickness of the rectangular waveguide diaphragm increases by 0.2mm, the phase changes from -151.9° to -155° at a frequency of 16GHz. Figure 4 The rectangular waveguide diaphragm shown has a length a = 15.8 mm, a width b = 7.9 mm, and a thickness d = 0.2 mm (30.2 mm - 30 mm = 0.2 mm). At a frequency of 16 GHz, the phase difference is 3°. If phase adjustment needs to be increased, the number of diaphragms can be increased. Alternatively, diaphragms of varying thickness can be designed to achieve varying step phase adjustment.

[0038] In summary, the present invention utilizes a vacuum-sealed window, an insulated waveguide, a polarization network, a waveguide coupler, a cryogenic amplifier, and a vacuum refrigeration system to achieve electromagnetic wave signal reception at a dual-polarization cryogenic receiving front end. The refrigeration system secures the insulated waveguide, polarization network, waveguide coupler, and cryogenic amplifier to a cold plate via cold tape to achieve refrigeration. The circuit of the present invention utilizes different electromagnetic wave transmission modes to form a dual-polarization signal, and transitions signal transmission to a rectangular waveguide form. The difference in transmission distance within the rectangular waveguide is utilized to add a waveguide diaphragm to adjust the phase difference of the dual-polarization signal. The present invention only requires disassembling the waveguide coupler and polarizer, adding a waveguide diaphragm of appropriate thickness, and then screwing it back together to quickly and effectively adjust the phase difference between the dual-polarization signals without affecting other electrical properties and maintaining the original assembly relationship. This is of strategic significance for the dual-polarization receiving front end, which requires phase consistency to achieve observation targets through combined observation of the observation array.

[0039] 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 dual-polarization low-temperature compact receiving front-end device capable of achieving rapid phase adjustment, characterized in that: The device comprises: a vacuum sealing window (11), a heat-insulating waveguide (10), a polarization network (12), a waveguide coupler (6), a low-temperature isolator (8), a low-temperature amplifier (2), and a vacuum refrigeration system; the vacuum refrigeration system comprises a cold head (9), a cold plate (1), an expander (7), a vacuum dewar (4), and a cold shield (3); The cold head (9), cold plate (1), polarization network (12), waveguide coupler (6), cryogenic isolator (8) and cryogenic amplifier (2) are all located in the cold shield (3); the cold shield (3) is located in the vacuum dewar (4); the vacuum sealing window (11) is mounted on the vacuum dewar (4); one end of the thermal insulation waveguide (10) is connected to the vacuum sealing window (11), and the other end is connected to the cold shield (3); The cold plate (1) is mounted on the cold head (9), and the low-temperature amplifier (2), waveguide coupler (6) and low-temperature isolator (8) are all mounted on the cold plate (1); the expander (7) is located outside the vacuum dewar (4) and is used to provide cold energy for the cold head (9); the vacuum sealing window (11) is mounted on the vacuum dewar (4), the heat-insulating waveguide (10) is mounted on the vacuum sealing window (11) and is located inside the vacuum dewar (4), one end of the heat-insulating waveguide (10) is connected to the vacuum sealing window (11), and the other end is connected to the cold shield (3); the input interface of the polarization network (12) is connected to the cold shield (3), and the output interface of the polarization network (12) is connected to the input interface of the waveguide coupler (6); the output interface of the waveguide coupler (6) is connected to the input interface of the low-temperature isolator (8), and the output interface of the low-temperature isolator (8) is connected to the input interface of the low-temperature amplifier (2); The heat-insulating waveguide (10) transmits the signal to the polarization network (12), and the polarization network (12) performs dual-polarization on the signal into two outputs. The output interface of the polarization network (12) adopts a rectangular waveguide interface. By arranging a rectangular waveguide diaphragm (13) between the output interface of the polarization network (12) and the input interface of the waveguide coupler (6), the thickness and number of the rectangular waveguide diaphragm (13) are adjusted to achieve phase adjustment of the device.

2. The dual-polarization low-temperature compact receiving front-end device capable of achieving rapid phase adjustment according to claim 1, characterized in that: The vacuum dewar (4) is made of aluminum and is polished to reduce cold radiation under vacuum.

3. The dual-polarization low-temperature compact receiving front-end device capable of achieving rapid phase adjustment according to claim 1, characterized in that: The cold shield (3) is used to isolate the cold energy of the cold head (9), and the cold shield (3) is made of aluminum plated with nickel and then polished.

4. The dual-polarization low-temperature compact receiving front-end device capable of achieving rapid phase adjustment according to claim 1, characterized in that: The cold plate (1) is U-shaped and is fixed to the cold head (9) by screws (5); the low-temperature amplifier (2) and the low-temperature isolator (8) are cooled to below 10K under the action of the cold plate (1).

5. The dual-polarization low-temperature compact receiving front-end device capable of achieving rapid phase adjustment according to claim 1, characterized in that: The vacuum sealing window (11) is a metal structure processed by aluminum gold plating process, which is in the working temperature range of 300K. The vacuum sealing window (11) realizes wave transmission through the sealing film.

6. The dual-polarization low-temperature compact receiving front-end device capable of achieving rapid phase adjustment according to claim 1, characterized in that: The thermal insulation waveguide (10) is a metal structure made of glass fiber material G10 through a metal copper gold plating process and then polished; the thermal insulation waveguide (10) is used to physically isolate the 10K cold plate (1) and the polarization network (12) to 300K; and a weight-reducing circular hole is provided on the thermal insulation waveguide (10).

7. The dual-polarization low-temperature compact receiving front-end device capable of realizing rapid phase adjustment according to claim 1, characterized in that: The cold head (9) and the cold plate (1) are both made of copper using a gold plating process and are polished.

8. The dual-polarization low-temperature compact receiving front-end device capable of realizing rapid phase adjustment according to claim 1, characterized in that: The waveguide coupler (6) is connected to the output interface of the polarization network (12) via a screw; the output interface of the waveguide coupler (6) is connected to the input interface of the low-temperature isolator (8) via a coaxial cable; the output interface of the low-temperature isolator (8) is connected to the input interface of the low-temperature amplifier (2).

9. The dual-polarization low-temperature compact receiving front-end device capable of realizing rapid phase adjustment according to claim 1, characterized in that: The vacuum sealing window (11) and the heat-insulating waveguide (10) adopt a circular waveguide transmission form; The input interface of the polarization network (12) is a circular waveguide interface, and the output interface is a rectangular waveguide interface; The input interface of the waveguide coupler (6) is a rectangular waveguide interface, and the output interface is a coaxial SMA interface; The low-temperature isolator (8) and the low-temperature amplifier (2) adopt a coaxial transmission form, and both contain radio frequency circuits composed of microstrip printed boards and devices.

10. The dual-polarization low-temperature compact receiving front-end device capable of realizing rapid phase adjustment according to claim 9, characterized in that: The circular waveguide interface and the rectangular waveguide interface are fixed by screws.

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