Pin structure of low-temperature superconducting radio frequency coaxial connector
By using ceramic insulators and an integrally molded pin structure in the N-type RF coaxial connector, combined with a stress relief groove design, the problem of pin cracking and falling off in a low-temperature superconducting environment is solved, achieving high-reliability signal transmission and sealing performance.
Patent Information
- Application Number
- CN202422422882.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-09
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-10-09
AI Technical Summary
Existing N-type RF coaxial connectors are difficult to meet the insulation, vacuum sealing and low-temperature resistance requirements in the field of low-temperature superconductivity, and the pins are prone to cracking or falling off during multiple plugging and unplugging.
The insulator is made of ceramic material. The pin body and the insulator are integrally formed and designed as a deformation part, a connection part and an insertion part. A stress relief groove is set on the transition piece, and the connection is made by vacuum brazing to ensure the stability and durability of the connection between the pin and the ceramic.
The durability and coaxiality of the pins are improved, material costs are reduced, and the reliability and vacuum sealing performance of multiple plugging and unplugging in low-temperature environments are ensured.
Smart Images
Figure CN223378469U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of low-temperature superconducting N-type radio frequency coaxial connectors, in particular to a pin structure of a low-temperature superconducting radio frequency coaxial connector. Background Art
[0002] RF coaxial connectors are essential components used in electronic communication systems, installed on communication cables and instruments. They provide both mechanical connection and ensure the smooth transmission of electromagnetic signals. The rapid development of RF technology and the increasing complexity of operating conditions have placed higher demands on RF coaxial connectors, requiring them to not only ensure reliable mechanical connections but also operate in low-temperature and vacuum environments.
[0003] Since the invention of the N-type RF coaxial connector by Paul Neill of Bell Labs in the 1940s, Figure 1 This N-type coaxial connector, characterized by excellent high-frequency transmission performance, strong anti-interference capabilities, and easy and reliable installation, has become one of the most common coaxial connector types in wireless communication and sensor systems. This N-type RF coaxial connector typically consists of an inner conductor, an outer conductor, an insulator, and a pin. The inner and outer conductors are the center conductor and outer metal shield, respectively, separated by an insulator to prevent signal interference and leakage. The pin is the core of the connector, used to insert and remove the inner conductor to complete signal transmission.
[0004] In the field of low-temperature superconductivity, N-type RF coaxial connectors are often used for signal transmission between vacuum and atmosphere. Therefore, higher insulation requirements, vacuum sealing requirements and low-temperature resistance requirements are put forward based on traditional N-type RF coaxial connectors. The mechanical connection and plastic insulation methods of existing N-type RF coaxial connectors are difficult to meet.
[0005] To meet the requirements for the use of N-type RF coaxial connectors in the low-temperature superconducting field, ceramics with better insulation properties need to be used as the insulator of the RF coaxial connector. At the same time, vacuum brazing is used to connect the different components of the RF coaxial connector to ensure reliable vacuum sealing performance. However, this also brings many challenges:
[0006] The insulator is made of ceramic, which also greatly limits the material of the center pin. In order to avoid brazing cracks caused by large differences in thermal expansion coefficients during brazing, the pin is usually made of materials such as Kovar alloy and molybdenum with a thermal expansion coefficient close to that of ceramic. Copper cannot be used due to its large thermal expansion coefficient.
[0007] In addition, the structure between the metal pin and the insulator requires an additional transition piece with a thermal expansion coefficient close to that of the insulator, but this also reduces the coaxiality between the pin and the outer conductor, see Figure 2signal;
[0008] During use, N-type RF coaxial connectors are frequently plugged and unplugged in low-temperature environments. The plugging and unplugging forces are transmitted through the pins to the product's brazed joints, causing cracks in the brazed joints after repeated use. Even more serious, the connector may fall off. Therefore, it is necessary to design a pin structure with a ceramic insulator, an integrated transition piece and pin body, capable of brazing and repeated plugging and unplugging. Utility Model Content
[0009] In order to solve the technical problems existing in the above background technology, the present utility model provides a.
[0010] The technical solution of this utility model is as follows:
[0011] A pin structure of a low-temperature superconducting radio frequency coaxial connector, wherein an insulator is placed in an outer cylinder, and the pin body is inserted into the insulator. The insulator is designed as a boss with a through hole in the middle for the pin body to penetrate. The outer surface of the insulator is connected to the outer cylinder by vacuum brazing. The pin body as a whole extends longitudinally and is an integrally formed structure. From top to bottom, it is divided into a deformation part, a connecting part and an insertion part. The diameter of the insertion part is smaller than the diameter of the connecting part. A deformation groove is provided circumferentially on the deformation part. The connecting part is a transition piece. The lower surface of the transition piece is connected to the upper surface of the insulator by vacuum brazing. A plurality of stress relief grooves opening downward are provided at the connection between the transition piece and the insulator.
[0012] The cross section of the transition piece is circular and bears stress evenly. The depth of the stress relief groove on the transition piece is no more than 2 / 3 of the thickness of the transition piece and is evenly distributed on the transition piece. After calculation and stress analysis, it can be seen that the stress is evenly dispersed during use to achieve the purpose of stress relief.
[0013] The cross-section of the pin body is circular, with a diameter in the range of 1-5mm. Considering the processing cost, the circular cross-section is more convenient to process. The pin body can be made of stainless steel, nickel, Kovar alloy 4J29 / 4J33, oxygen-free copper, molybdenum, tungsten, and beryllium copper.
[0014] Preferably, the pin body can also be designed to have a polygonal cross-section to reduce relative rotation between the pin body and the insulator. Furthermore, the through hole of the insulator is opened to match the cross-sectional shape of the pin body.
[0015] The insulator is a circular boss, which is divided into an upper boss and a lower boss. The radius of the upper boss is smaller than that of the lower boss. The insulator material can be selected from 95%, 97%, 99% alumina, zirconia, and zirconia toughened alumina.
[0016] The upper surface and inner surface of the boss on the insulator are provided with a metallized layer and connected to the pin body by vacuum brazing. The insulator and the pin body are clearance-matched, and the clearance is between 0.05-0.2mm.
[0017] A metallized layer is provided on the side surface of the lower boss of the insulator and is connected to the outer cylinder by vacuum brazing.
[0018] The diameter of the boss on the insulator is larger than the diameter of the transition piece. The design of the boss can make the pin more stably fixed during use and can also be firmly connected to the outer tube.
[0019] The deformation groove is located in the middle of the deformation part. The cross section of the deformation groove is square. It bends under force during use and has a certain deformation space, which serves as the concentrated force point of the entire pin.
[0020] The utility model provides a method for using a pin structure of a low-temperature superconducting radio frequency coaxial connector, which includes: inserting a pin body into a through hole of an insulator, providing a metallized layer on the upper surface and inner surface of the upper boss, and vacuum brazingly connecting the pin body; installing the insulator into an outer cylinder, providing a metallized layer on the side of the lower boss, and vacuum brazingly connecting the pin body to the outer cylinder, wherein the pin body is machine-formed, the pin body is provided with a deformation groove for bending, the upper surface and inner surface of the upper boss of the insulator are metallized, and a through hole is left in the middle to allow the pin body to penetrate.
[0021] The utility model provides a low-temperature superconducting radio frequency coaxial connector pin structure with the following beneficial effects:
[0022] The insulator has stable material properties, a small expansion coefficient, and is not prone to cracking. Compared with the traditional brazing process that only metalizes the upper surface, it expands the welding area, making the connection between the pin and the ceramic more firm and reliable.
[0023] The transition piece part of the pin body is also integrally formed, which solves the risk of the pin cracking from the transition piece after multiple bending, reduces material costs, improves processing efficiency, ensures the coaxiality of the pin body, reduces processing complexity, and reduces production costs.
[0024] At the same time, the design of the stress relief groove can effectively relieve and reduce the brazing stress between the transition piece and the ceramic, thereby improving product reliability. The deformation groove located in the deformation part effectively improves the bending resistance of the pin. The N-type RF coaxial connector of the utility model can frequently perform multiple plugging, unplugging, bending and debugging actions in a low temperature environment.
[0025] The utility model can meet the insulation requirements, vacuum sealing requirements and low temperature resistance requirements of the N-type RF coaxial connector while ensuring signal transmission, and adopts a vacuum brazing connection method to realize the connection between different components of the RF coaxial connector to ensure reliable vacuum sealing performance.
[0026] Thanks to the effect of the pin seal structure of the utility model on relieving brazing stress, more choices of pin materials are available, such as oxygen-free copper widely used in the vacuum field, which has better conductivity and ductility. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] In the attached figure:
[0028] Figure 1 A simplified schematic diagram of an N-type RF coaxial connector in the background art;
[0029] Figure 2 A cross-sectional view of a conventional coaxial connector with a split transition piece in the background art;
[0030] Figure 3 This is a schematic diagram of the overall structure of a low-temperature superconducting radio frequency coaxial connector;
[0031] Figure 4 This is a schematic diagram of a pin body in a pin structure of a low-temperature superconducting radio frequency coaxial connector;
[0032] Figure 5 The present invention is a cross-sectional view of a pin body in a pin structure of a low-temperature superconducting radio frequency coaxial connector.
[0033] The components represented by the reference numerals in the figure are:
[0034] 1. Insulator; 2. Outer tube; 3. Pin body; 4. Deformation groove; 5. Transition piece; 6. Stress relief groove. DETAILED DESCRIPTION
[0035] The technical solution of this utility model is as follows:
[0036] See also Figure 3 and Figure 4 , a pin structure of a low-temperature superconducting radio frequency coaxial connector, the insulator 1 is placed in the outer tube 2, the pin body 3 is inserted into the insulator 1, the insulator 1 is designed as a boss, and a through hole is provided in the middle for the pin body 3 to penetrate, the outer surface of the insulator 1 is connected to the outer tube 2 by vacuum brazing, the pin body 3 extends as a whole along the longitudinal direction, and is an integrated molding structure, which is divided into a deformation part, a connecting part and an insertion part from top to bottom. The diameter of the insertion part is smaller than the diameter of the connecting part, and a deformation groove 4 is provided circumferentially on the deformation part. The connecting part is a transition piece 5, and the lower surface of the transition piece 5 is connected to the upper surface of the insulator 1 by vacuum brazing. A plurality of stress relief grooves 6 with downward openings are provided at the connection between the transition piece 5 and the insulator 1.
[0037] The cross section of the transition piece 5 is circular and bears the force evenly.
[0038] The depth of the stress relief groove 6 on the transition piece 5 is no more than 2 / 3 of the thickness of the transition piece 5, the width is 0.1-0.5mm, and the depth is 0.3-0.7mm. It is evenly distributed on the transition piece 5, and the force is evenly dispersed during use to achieve the purpose of stress relief. It can effectively relieve and reduce the brazing stress between the transition piece 5 and the insulator 1, thereby improving product reliability.
[0039] The cross-section of the pin body 3 is circular, with a diameter in the range of 1-5 mm. Considering the processing cost, the circular cross-section is more convenient to process. The design of the pin body 3 has the effect of relieving brazing stress, so that there are more choices for the material of the pin body 3, such as oxygen-free copper widely used in the vacuum field, which has better conductivity and ductility.
[0040] The material of the pin body 3 can also be stainless steel, nickel, Kovar alloy 4J29 / 4J33, molybdenum, tungsten, and beryllium copper. The pin body 3 is formed into one piece through machining, which solves the risk of the pin body 3 cracking after multiple bending, reduces material costs, and improves processing efficiency.
[0041] Preferably, the pin body 3 may also be designed to have a polygonal cross-section to reduce relative rotation between the pin body 3 and the insulator 1 . Furthermore, the through hole of the insulator 1 is opened to match the cross-sectional shape of the pin body 3 .
[0042] The deformation groove 4 is located in the middle of the deformation part. The cross section of the deformation groove 4 is square. The groove width is within the range of 0.5-1.0mm and the groove length is within the range of 1-5mm. Figure 4 and Figure 5 As shown in the figure, when it is bent under force during use, there is a certain deformation space, which is the concentrated force point of the entire pin, effectively improving the bending resistance of the pin body 3.
[0043] The insulator 1 is a circular boss, which is divided into an upper boss and a lower boss. The radius of the upper boss is smaller than that of the lower boss. The material of the insulator 1 can be selected from 95%, 97%, 99% alumina, zirconia, and zirconia toughened alumina.
[0044] The upper and inner surfaces of the upper boss of insulator 1 are metallized and vacuum-brazed to the pin body 3. The side surfaces of the lower boss of insulator 1 are metallized and vacuum-brazed to the outer tube 2. Compared to traditional brazing processes that only metallize the upper surface, this expands the welding area and makes the connection between the pin and the ceramic more secure and reliable.
[0045] As shown in the figure, the insulator 1 is metallized by the molybdenum-manganese method at a depth of 2-5 mm on the outer side, the boss surface, and the upper inner side surface. The thickness of the metallization layer is: MoMn: 10-30 μm, and the nickel plating layer is: 2-10 μm.
[0046] The diameter of the through hole of the insulator 1 is larger than the diameter of the insertion portion of the pin body 3 , and the insulator 1 and the pin body 3 are clearance-fitted, with the clearance being between 0.05-0.2 mm.
[0047] The diameter of the boss on the insulator 1 is larger than the diameter of the transition piece 5 . The design of the boss can fix the pin more stably during use and can also be firmly connected to the outer tube 2 .
[0048] When sealing the pin, the insulator 1 is placed in the outer tube 2 to ensure that the two parts are tightly attached. Silver-based solder is placed at the fitting point between the outer metallization layer of the insulator 1 and the inner side of the outer tube 2. The same solder is placed on the metallization layer of the insulator 1. The pin body is inserted into the through hole of the insulator 1. The transition piece 5 fits well with the boss on the insulator 1. Then, it is placed in a vacuum furnace for vacuum brazing. After being taken out of the furnace, the air tightness of the N-type RF coaxial connector and the coaxial dimensions of the pin body 3 and the outer tube 2 are tested.
[0049] The utility model provides a method for using the pin structure of a low-temperature superconducting radio frequency coaxial connector, which is as follows: the pin body 3 is inserted into the through hole of the insulator 1, and the upper surface and inner surface of the upper boss are provided with a metallized layer, which is vacuum brazed to the pin body 3; the insulator 1 is installed in the outer tube 2, and the side surface of the lower boss is provided with a metallized layer, which is vacuum brazed to the outer tube 2, wherein the pin body 3 is integrally machined and formed, and the pin body 3 is provided with a deformation groove 4 for bending, and the upper surface and inner surface of the upper boss of the insulator 1 are metallized, and a through hole is left in the middle to allow the pin body 3 to penetrate.
[0050] The utility model provides a low-temperature superconducting radio frequency coaxial connector pin structure with the following beneficial effects:
[0051] The material properties of the insulator 1 are stable, the expansion coefficient is small, and it is not easy to crack. Compared with the traditional brazing process in which only the upper surface is metallized, the welding area is expanded, making the connection between the pin and the ceramic more firm and reliable.
[0052] The transition piece 5 of the pin body 3 is also integrally formed, which solves the risk of the pin cracking from the transition piece 5 after multiple bending, reduces material costs, improves processing efficiency, ensures the coaxiality of the pin body 3, reduces processing complexity, and reduces production costs.
[0053] At the same time, the design of the stress relief groove 5 can effectively relieve and reduce the brazing stress between the transition piece 5 and the ceramic, thereby improving product reliability. The deformation groove 4 located in the deformation part effectively improves the bending resistance of the pin. The N-type RF coaxial connector of the present invention can frequently perform multiple plugging, unplugging, bending and debugging operations in a low temperature environment.
[0054] The utility model can meet the insulation requirements, vacuum sealing requirements and low temperature resistance requirements of the N-type RF coaxial connector while ensuring signal transmission, and adopts a vacuum brazing connection method to realize the connection between different components of the RF coaxial connector to ensure reliable vacuum sealing performance.
[0055] Thanks to the effect of the pin seal structure of the utility model on relieving brazing stress, more choices of pin materials are available, such as oxygen-free copper widely used in the vacuum field, which has better conductivity and ductility.
Claims
1. A pin structure of a low-temperature superconducting radio frequency coaxial connector, wherein an insulator (1) is placed in an outer cylinder (2), and an insertion portion of a pin body (3) is inserted into the insulator (1), characterized in that: The insulator (1) is designed as a boss, with a through hole in the middle for the pin body (3) to penetrate, and the outer surface of the insulator (1) is connected to the outer cylinder (2) by vacuum brazing. The plug body (3) extends longitudinally as a whole and is an integrally formed structure. It is divided into a deformation portion, a connection portion and an insertion portion from top to bottom. The diameter of the insertion portion is smaller than the diameter of the connection portion. The deformation portion is circumferentially provided with a deformation groove (4). The connection portion is a transition piece (5). The lower surface of the transition piece (5) is vacuum brazed to the upper surface of the insulator (1). A plurality of stress relief grooves (6) with downward openings are provided at the connection portion between the transition piece (5) and the insulator (1).
2. The pin structure of a low-temperature superconducting radio frequency coaxial connector according to claim 1, characterized in that: The insulator (1) is a circular boss, which is divided into an upper boss and a lower boss, and the radius of the upper boss is smaller than the radius of the lower boss.
3. The pin structure of a low-temperature superconducting radio frequency coaxial connector according to claim 2, characterized in that: The upper surface and inner surface of the upper boss of the insulator (1) are provided with a metallized layer and are connected to the pin body (3) by vacuum brazing.
4. The pin structure of a low-temperature superconducting radio frequency coaxial connector according to claim 2, characterized in that: A metallized layer is provided on the side surface of the lower boss of the insulator (1) and is connected to the outer cylinder (2) by vacuum brazing.
5. The pin structure of a low-temperature superconducting radio frequency coaxial connector according to any one of claims 2 to 4, characterized in that: The cross section of the transition piece (5) is circular.
6. The pin structure of a low-temperature superconducting radio frequency coaxial connector according to claim 5, characterized in that: The diameter of the upper boss of the insulator (1) is greater than the diameter of the transition piece.
7. The pin structure of a low-temperature superconducting radio frequency coaxial connector according to claim 1, characterized in that: The deformation groove (4) is located in the middle of the deformation part.
8. The pin structure of a low-temperature superconducting radio frequency coaxial connector according to claim 1, characterized in that: The depth of the stress relief groove (6) is no more than 2 / 3 of the thickness of the transition piece (5).
9. The pin structure of a low-temperature superconducting radio frequency coaxial connector according to claim 3, characterized in that: The insulator (1) and the pin body (3) are clearance-matched, with the clearance being between 0.05 and 0.2 mm.
10. The pin structure of a low-temperature superconducting radio frequency coaxial connector according to claim 1, characterized in that: The diameter of the pin body (3) is in the range of 1-5 mm.