CN-122000758-A - Conductive connection structure with single-ended limiting inner conductor and radio frequency coaxial adapter

CN122000758ACN 122000758 ACN122000758 ACN 122000758ACN-122000758-A

Abstract

The invention discloses a conductive connection structure with single end limiting of an inner conductor and a radio frequency coaxial adapter, wherein the conductive connection structure comprises the inner conductor, a central insulating medium and an outer conductor which are coaxially arranged, the central insulating medium is axially fixed in an inner cavity of the outer conductor, the inner conductor is coaxially arranged in a central inner hole of the central insulating medium in a penetrating mode, the inner conductor is provided with a diameter abrupt change step which is adaptive to the specification of interfaces at two ends of the standard-crossing adapter, only axial hard limiting is formed by abutting the step with the end face of the medium, the integral of limiting and impedance transition is realized by multiplexing an inherent structure, no additional axial hard limiting structure is arranged at other parts, and the inner conductor and the inner hole of the medium are in interference fit to form axial static friction constraint. The invention breaks through the technical prejudice that the inner conductor of the adapter must be limited at two ends in two directions, solves the pain point that the performance and the reliability of the prior art are difficult to be compatible, synchronously optimizes the radio frequency performance, the limiting reliability and the mass production economy in a very small design space, and meets the requirements of a high-frequency broadband radio frequency system.

Inventors

WANG XIURONG
WANG XUEMIN
WANG FAQI

Assignees

深圳海普瑞丽科技有限公司

Dates

Publication Date: 20260508
Application Date: 20260327

Claims (10)

1. The utility model provides a single-ended spacing conductive connection structure of inner conductor, is applied to and strides specification radio frequency coaxial adapter, includes coaxial inner conductor, central insulating medium and outer conductor that sets up, the both ends of inner conductor are big head end and little head end respectively, and inner conductor corresponds big head end and little head end and is provided with the diameter abrupt change step of the rated specification of adaptation both ends interface, diameter abrupt change step face little head end, central insulating medium axial fixed mounting in the inner chamber of outer conductor, the inner conductor coaxial wears to locate in the central hole of central insulating medium, The inner conductor is only axially abutted with the end face of the central insulating medium, which faces the big end, through the diameter abrupt change step to form a unique axial hard limit structure, and the rest parts of the inner conductor are free of any axial hard limit structure which is rigidly abutted with the central insulating medium or the outer conductor; the inner conductor is in interference fit with the central inner hole of the central insulating medium from the diameter abrupt change step to the outer wall of the small end, so that static friction constraint on axial movement of the inner conductor is formed.
2. The conductive connection structure of single-ended limit of inner conductor according to claim 1, wherein the central insulating medium is made of glass fiber or silicon dioxide filled modified polytetrafluoroethylene.
3. The conductive connection structure with single-ended limit for inner conductor according to claim 2, wherein the elastic modulus of the filled and modified polytetrafluoroethylene is not lower than 1500mpa, the relative dielectric constant at 25 ℃ is 2.2-2.4, and the loss tangent at 10ghz is not more than 0.0008.
4. The single-ended limited conductive connection structure of an inner conductor according to claim 1, wherein the inner conductor is sequentially provided with a big end adapting section, a middle transition section and a small end adapting section with decreasing diameters along the axial direction, and the axial length of the middle transition section accounts for 20% -21% of the total length of the inner conductor.
5. The conductive connection structure with single-ended limit for an inner conductor according to claim 4, wherein the outer diameter of the middle transition section is between the outer diameter of the big end adaptation section and the outer diameter of the small end adaptation section to form a continuous smooth diameter decreasing structure, the ratio of the outer diameter of the middle transition section to the outer diameter of the big end adaptation section is 0.68-0.78, and the ratio of the outer diameter of the middle transition section to the outer diameter of the small end adaptation section is 1.58-1.85.
6. The conductive connection structure with single-ended limit for an inner conductor according to claim 5, wherein the axial length of the big-end adapting section is 44% -47% of the total length of the inner conductor, and the axial length of the small-end adapting section is 32% -35% of the total length of the inner conductor.
7. The conductive connection structure of single-ended limit of inner conductor according to claim 1, wherein the butt joint interfaces at two ends of the outer conductor are of a straight wall structure without a bell mouth, two cylindrical center holes with different diameters are sequentially formed in the inner wall of the outer conductor along the axial direction, a single annular positioning clamping groove is formed at the joint of the two cylindrical center holes, and the central insulating medium is clamped in the annular positioning clamping groove through an annular positioning step of the outer wall, so that axial play-free locking of the central insulating medium is realized.
8. The conductive connection structure with single end limiting of the inner conductor according to claim 7, wherein the outer edge of the outer conductor corresponding to the big end is sleeved with a connection screw sleeve, an axial limiting structure with an annular limiting clamping groove and an elastic clamping spring matched is arranged between the connection screw sleeve and the outer conductor, the axial limiting structure limits the axial movement and the falling of the connection screw sleeve relative to the outer conductor, so that the axial position of the connection screw sleeve is kept stable relative to the outer conductor, and the connection screw sleeve can freely rotate along the circumferential direction.
9. The conductive connection structure of single-ended limit of inner conductor according to claim 8, wherein an annular assembly guiding chamfer is provided on an inner wall of the butt end of the connection screw sleeve, the assembly guiding chamfer extends along an axial direction toward the butt end direction, and integrally protrudes out of an end face of the butt end of the outer conductor.
10. A radio frequency coaxial adapter for interconnection across a specification radio frequency interface, the radio frequency coaxial adapter comprising an inner conductor single ended limited conductive connection structure as claimed in any one of claims 1 to 9.

Description

Conductive connection structure with single-ended limiting inner conductor and radio frequency coaxial adapter Technical Field The invention relates to the technical field of conductive connection, in particular to a conductive connection structure with single-ended limiting inner conductor and a radio frequency coaxial adapter. Background The radio frequency coaxial adapter is a core basic component for realizing signal interconnection and switching in a radio frequency microwave transmission system, and is mainly used for radio frequency signal interconnection among radio frequency transmission cables, active/passive functional devices, system functional modules, test measuring instruments and complete equipment, and meanwhile provides stable impedance matching, reliable electromagnetic shielding and mechanical connection guarantee for a transmission link. The large-small-head adapter (such as an N-type to SMA-type adapter structure with different interface specifications) adapting to different standard radio frequency interface series is a necessary element for solving the interconnection requirement of different interface standard devices in a radio frequency system, and is widely applied to the fields of 5G/6G mobile communication, millimeter wave radar, satellite communication, aerospace, electronic test measurement and the like. The typical radio frequency coaxial adapter adopts a coaxial transmission line basic structure, is mainly composed of an inner conductor (also called a contact pin), an outer conductor, a central insulating medium (also called an insulator) positioned between the inner conductor and the outer conductor, a matched locking connection mechanism and the like which are coaxially arranged, and can support low-loss and high-fidelity transmission of transverse electromagnetic waves (TEM mode). Along with the continuous evolution of the radio frequency system towards the high-frequency broadband, small-sized integration and high reliability, the radio frequency system provides severe design requirements for the radio frequency transmission performance, mechanical stability and environmental adaptability of various cross-specification radio frequency coaxial adapters. The design space for optimizing and adjusting is extremely narrow, firstly, the size and the fit tolerance of the butt joint interface at the two ends of the adapter are forcedly limited by IEC 6069 series international standard and cannot be adjusted randomly, otherwise, the compatibility with standard devices is lost, secondly, the radio frequency transmission link must be strictly matched with the standard characteristic impedance of 50 omega commonly used in industry, the ratio of the inner diameter of an outer conductor to the outer diameter of an inner conductor of a corresponding coaxial structure is required to be stably maintained at about 3.44, the tiny adjustment of the outer diameter of the inner conductor can directly cause the large deviation of the local characteristic impedance to cause the radio frequency performance deterioration, thirdly, under the development trend of industry miniaturization, the inner cavity installation space of the adapter is fixed, and the redundancy-free space is used for adding an additional impedance compensation structure and a limiting component. Under the severe rigidity constraint, the structural design of the inner conductor bears two core functions of impedance matching and axial limiting, and the design requirements of the two core functions are in conflict naturally, so that the extremely small optimizing design space is further compressed. According to the basic theory of the coaxial transmission line, the characteristic impedance of the radio frequency coaxial structure is determined by the outer diameter of the inner conductor, the inner diameter of the outer conductor and the relative dielectric constant of the middle insulating medium, and the uniformity of the whole-course characteristic impedance of the transmission link is a core premise for guaranteeing the undistorted and low-loss transmission of radio frequency signals. For the cross-specification radio frequency coaxial adapter, the diameter transition structure of the inner conductor is not only a core object of impedance matching design, but also a natural carrier of an axial limiting structure, so that the axial positioning and limiting reliability of the inner conductor is a core design dimension which is designed cooperatively with radio frequency transmission performance and is important equally, and the design of the limiting structure directly determines the assembly consistency, mechanical connection stability, long-term working reliability and impedance matching performance of the adapter in a full working frequency band. The fixed design consensus and the ubiquitous technical prejudice are formed in the field for a long time, in order to ensure the axial stability of the inner conductor when the c