CN217934176U

CN217934176U - SFT semi-hard cable without insulation medium series motion

Info

Publication number: CN217934176U
Application number: CN202222404712.2U
Authority: CN
Inventors: 马常彪; 张博文; 金鑫; 郝曼曼; 甘福同; 徐凡
Original assignee: Cetc Shanghai Microwave Communication Co ltd
Current assignee: Cetc Shanghai Microwave Communication Co ltd
Priority date: 2022-09-09
Filing date: 2022-09-09
Publication date: 2022-11-29
Anticipated expiration: 2032-09-09

Abstract

The utility model provides a SFT semi-hard cable that no insulating medium moved, this SFT semi-hard cable include micropore insulating medium, inner conductor and outer conductor, and wherein, micropore insulating medium cladding is in the outside of inner conductor, and the outer conductor cladding is in micropore insulating medium's the outside. The micropore insulation medium of the SFT semi-hard cable is micropore polytetrafluoroethylene, and the total volume percentage of micropores in the micropore polytetrafluoroethylene is 2-3.5%. The inner conductor of the SFT semi-hard cable is an oxygen-free copper wire with a silver-plated surface, and the outer conductor is a seamless oxygen-free copper wire. The SFT semi-hard cable has no phenomenon of insulating medium crosstalk when a tin soldering joint is welded at 250 ℃ or the semi-hard cable is welded; under the environment temperature change of minus 55 to 125 ℃, the volume expansion or shrinkage phenomenon of the insulating medium can not occur; when the cable is bent, the cross section of the bent part is not obviously deformed and the outer conductor is not broken, and the radio frequency performance is stable; various coaxial connectors matched with the existing SFT semi-hard cable can be directly used; the cable is suitable for various use environments of the existing SFT semi-hard cable.

Description

SFT semi-hard cable without insulation medium series motion

Technical Field

The utility model belongs to the radio frequency coaxial cable field, concretely relates to SFT semi-hard cable that non-insulation medium moved.

Background

The SFT semi-rigid cable is a radio frequency cable with a coaxial structure and consists of an inner conductor, an insulating medium and an outer conductor. The inner conductor is made of silver-plated copper wire material, the insulating medium is made of Polytetrafluoroethylene (PTFE) solid material, and the outer conductor is made of seamless oxygen-free copper pipe. The inner conductor and the outer conductor have good conductivity, and the polytetrafluoroethylene has low dielectric constant, loss tangent and excellent physical and chemical stability, so that the semi-rigid cable has excellent radio frequency performance and environmental adaptability. The SFT semi-hard cable has the characteristics of simple structure, good rigidity, good dimensional stability, strong environmental adaptability and the like, and is widely used for electrical connection of antennas of electronic equipment, feeder networks and radio frequency modules.

However, when the SFT semi-rigid cable is soldered at 250 ℃ or at ambient temperature of-55 to 125 ℃, there is a large difference between the thermal expansion coefficient of the solid ptfe insulating medium and the thermal expansion coefficients of the inner and outer conductors (the thermal expansion coefficient of solid ptfe is about 10 to 15 × 10 ^-5 K, the coefficient of thermal expansion of copper is about 16.5X 10 ^-6 and/K), the solid polytetrafluoroethylene insulating medium expands when heated and generates larger internal stress between the inner conductor and the outer conductor, and when the axial expansion stress is larger than the adhesive force between the solid polytetrafluoroethylene insulating medium and the inner conductor and the outer conductor, the solid polytetrafluoroethylene insulating medium generates an outward extending end head in a string mode, and otherwise, the solid polytetrafluoroethylene insulating medium retracts inwards. When the cable is bent into a complex shape or is long enough, the axial adhesion force is large enough, and the outer conductor of the cable has microscopic defects, the situation that the solid polytetrafluoroethylene insulating medium breaks the outer conductor can occur.

In order to overcome the above defects of the SFT semi-hard cable, the currently mainly adopted solution is repeated aging at high and low temperatures, releasing the internal stress of the cable. However, in practical applications, while releasing the internal stress of the cable, the adhesion between the cable insulating medium and the inner conductor and the outer conductor is also reduced, the structural stability of the SFT semi-rigid cable is weakened, and the possibility of the occurrence of the dielectric crosstalk is increased, so that the problems of the dielectric crosstalk and the outer conductor being burst cannot be fundamentally solved.

SUMMERY OF THE UTILITY MODEL

For solving prior art's problem, the utility model provides a replace the entity polytetrafluoroethylene insulating medium among the SFT semi-hard cable of prior art for micropore polytetrafluoroethylene insulating medium, and micropore's total volume and polytetrafluoroethylene among the micropore polytetrafluoroethylene, two kinds of materials of copper are the thermal expansion volume difference under the maximum temperature difference in soldering assembly or service environment is equivalent, make when SFT semi-hard cable when soldering assembly or service temperature rise, polytetrafluoroethylene insulating medium's inflation is at first used for filling the reservation micropore of self, and can not appear stretching out/retracting cable end or prop broken phenomenon with the outer conductor.

The utility model provides a SFT semi-hard cable that no insulating medium moved. The utility model has the following concrete technical scheme:

the utility model provides a SFT semi-hard cable that no insulating medium moved, a serial communication port, including micropore insulating medium, inner conductor and outer conductor, wherein, micropore insulating medium cladding is in the outside of inner conductor, and the outer conductor cladding is in micropore insulating medium's the outside.

The utility model provides a SFT semi-hard cable that no insulating medium moved in a cluster still has such technical characteristic, and wherein, micropore insulating medium is micropore polytetrafluoroethylene.

The utility model provides a SFT semi-hard cable that no insulating medium moved in cluster still has such technical characteristic, and wherein, micropore's total volume percentage is 2 ~ 3.5% in the micropore polytetrafluoroethylene.

The utility model provides a SFT semi-hard cable that insulating medium moved in a cluster still has such technical characteristic, and wherein, the inner conductor is the silvered anaerobic copper line in surface, and the outer conductor is seamless anaerobic copper pipe.

Action and effect of the utility model

The utility model provides a SFT semi-hard cable that no insulating medium moved, this SFT semi-hard cable include micropore insulating medium, inner conductor and outer conductor, and wherein, micropore insulating medium cladding is in the outside of inner conductor, and the outer conductor cladding is in micropore insulating medium's the outside. The micropore insulation medium of the SFT semi-hard cable is micropore polytetrafluoroethylene, and the total volume percentage of micropores in the micropore polytetrafluoroethylene is 2-3.5%. The inner conductor of the SFT semi-hard cable is an oxygen-free copper wire with silver-plated surface, and the outer conductor is a seamless oxygen-free copper tube.

Therefore, compared with the prior art, the utility model provides a SFT semi-hard cable that non-insulation medium moved has following advantage:

(1) When a tin soldering joint or a semi-hard cable is soldered at 250 ℃, the phenomenon of insulating medium crosstalk cannot occur;

(2) Under the environment temperature change of minus 55 to 125 ℃, enough holding force is maintained between the insulating medium and the inner and outer conductors, and the insulating medium does not expand or contract in volume;

(3) When the SFT semi-rigid cable is bent, the cross section of the bent part cannot be obviously deformed and the outer conductor cannot be propped, and the radio frequency performance is stable.

Additionally, the utility model provides a SFT semi-hard cable that no insulating medium moved in cluster can also directly use the various coaxial connector that match with current SFT semi-hard cable, is applicable to current SFT semi-hard cable's various service environment.

Drawings

Fig. 1 is a schematic structural diagram of an SFT semi-hard cable without dielectric crosstalk according to an embodiment of the present invention.

Detailed Description

Terms used in the present invention generally have meanings commonly understood by those of ordinary skill in the art, unless otherwise specified.

In the following examples, various procedures and methods not described in detail are conventional methods well known in the art.

The reagents used in the following examples are commercially available and the experimental procedures and experimental conditions not specified are those conventional in the art.

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings.

< example 1>

The embodiment provides an SFT semi-hard cable without insulating medium crosstalk, and the specification of the SFT semi-hard cable corresponds to the existing semi-hard cable with the model number of SJ 50973/SFT-50-2-51.

Fig. 1 is a schematic structural diagram of an SFT semi-rigid cable without dielectric crosstalk according to an embodiment of the present invention. As shown in fig. 1, the SFT semi-rigid cable 4 without the series of insulating mediums includes a micro-porous insulating medium 2, an inner conductor 1 and an outer conductor 3, wherein the micro-porous insulating medium 2 covers the outer side of the inner conductor 1, and the outer conductor 3 covers the outer side of the micro-porous insulating medium 2.

The micropore insulating medium 2 of the SFT semi-hard cable 4 without the insulating medium moving in series is micropore polytetrafluoroethylene, the micropore polytetrafluoroethylene is formed by extruding polytetrafluoroethylene resin purchased from large-volume metalfluoride chemical (China) limited company, and the extrusion preparation method is the existing preparation method. The total volume percentage of micropores in the microporous polytetrafluoroethylene is 2-3.5%, the microporous insulating medium 2 plays a supporting role in structure, the coaxiality of an inner conductor and an outer conductor is ensured, and electromagnetic waves of a TEM mode are transmitted in the insulating medium on radio frequency; the inner conductor 1 of the SFT semi-hard cable 4 is an oxygen-free copper wire (purchased from Hengfeng copper wire Co., ltd., changzhou city) with silver-plated surface; the outer conductor 3 of the SFT semi-rigid cable 4 is a seamless oxygen free copper tube (purchased from oxygen free copper tube works in shanghai city), and the outer conductor 3 allows an electromagnetic field to propagate between the outer conductor and the inner conductor and prevents the electromagnetic field from leaking into the space.

The equivalent dielectric constant of the microporous polytetrafluoroethylene insulating medium of the SFT semi-hard cable without the insulating medium series connection is 1.88-1.96.

The structural dimensions of the SFT semi-rigid cable without dielectric crosstalk are listed in table 1.

TABLE 1

The characteristic impedance Z of the SFT semi-hard cable without the series of the insulating medium ₀ Calculated by the following formula, its characteristic impedance Z ₀ Is 50 omega +/-2 omega,

in the formula: d is the outer dimension of the inner conductor, D is the inner dimension of the outer conductor, epsilon _r Is the dielectric constant of the insulating medium.

The transmission rate of the SFT semi-hard cable without the insulating medium crosstalk is calculated by the following formula and is 71.5 to 72.5 percent,

in the formula: epsilon _r Is the dielectric constant of the insulating medium.

The dielectric constant of the solid ptfe insulating medium of the prior art SFT semi-rigid cable is about 2.08 and therefore its transmission rate is about 70%.

< example 2>

The embodiment provides an SFT semi-hard cable without insulating medium crosstalk, and the specification of the SFT semi-hard cable corresponds to the existing semi-hard cable with the model number of SJ 50973/SFT-50-3-51.

The SFT semi-rigid cable without dielectric crosstalk according to this embodiment is the same as that according to embodiment 1 except for the difference in size.

The total volume percentage of micropores in the microporous polytetrafluoroethylene of the SFT semi-hard cable without the insulating medium crosstalk in this embodiment is 2 to 3.5%.

The structural dimensions of the SFT semi-rigid cable without dielectric crosstalk are listed in table 2.

TABLE 2

The characteristic impedance Z of the SFT semi-hard cable without the dielectric medium series flow is calculated by the formula ₀ 50 omega +/-2 omega, and the transmission rate is 71.5-72.5%.

< test example >

In this test example, the SFT semi-hard cable without the series of the insulating medium in the above embodiment is subjected to the radio frequency characteristic and the mechanical characteristic test, and the test results are shown in table 3.

TABLE 3

As can be seen from table 3, the insulating medium of the SFT semi-rigid cable without the insulating medium crosstalk in the examples is equivalent to the adhesion, minimum bend radius, and radio frequency transmission characteristics (transmission frequency, voltage standing wave ratio, insertion loss, etc.) of the inner and outer conductors, and the conventional SFT semi-rigid cable.

In conclusion, compare with current SFT semi-hard cable, because the utility model discloses a SFT semi-hard cable that non-insulation medium moved in series except that transmission rate adjustment be 71.5% ~ 72.5%, insulation medium's dielectric constant adjustment be 1.88 ~ 1.96, its dimensional tolerance, insulation medium all are equivalent with inner and outer conductor's adhesive force, minimum bend radius and radio frequency transmission characteristic, consequently, the utility model discloses a SFT semi-hard cable that non-insulation medium moved in series can directly use various coaxial joint that match with current SFT semi-hard cable, also is applicable to the various service environment of current SFT semi-hard cable simultaneously.

In addition, because the solid polytetrafluoroethylene insulating medium in the SFT semi-hard cable in the prior art is replaced by the microporous polytetrafluoroethylene insulating medium, and the total volume of micropores in the microporous polytetrafluoroethylene is equivalent to the thermal expansion volume difference of two materials of polytetrafluoroethylene and copper under the maximum temperature difference in the soldering assembly or use environment, when the soldering assembly or use temperature of the SFT semi-hard cable rises, the expansion of the polytetrafluoroethylene insulating medium is firstly used for filling the reserved micropores of the SFT semi-hard cable, so that the phenomenon of insulating medium crosstalk cannot occur when a solder joint or the welding semi-hard cable is welded at 250 ℃; under the ambient temperature change of-55 to 125 ℃, the insulating medium and the inner and outer conductors maintain enough holding force, and the insulating medium does not expand or shrink in volume; when the antenna is bent, the cross section of the bent part is not obviously deformed and the outer conductor is not broken, and the radio frequency performance is stable.

The foregoing is a detailed description of embodiments that will enable those skilled in the art to make and use the invention. Based on the prior art, those skilled in the art should, without innovative efforts, make improvements or modifications only by means of analytical or analogical methods or limited enumeration, be within the scope of protection defined by the claims.

Claims

1. An SFT semi-hard cable without insulating medium series movement is characterized by comprising a micropore insulating medium, an inner conductor and an outer conductor,

the micropore insulating medium is coated on the outer side of the inner conductor, and the outer conductor is coated on the outer side of the micropore insulating medium.

2. An SFT semi-rigid cable with no dielectric crosstalk according to claim 1,

wherein, the micropore insulation medium is micropore polytetrafluoroethylene.

3. An SFT semi-rigid cable with no dielectric crosstalk according to claim 2,

wherein the total volume percentage of micropores in the microporous polytetrafluoroethylene is 2-3.5%.

4. An SFT semi-rigid cable without dielectric medium crosstalk according to claim 1,

wherein the inner conductor is an oxygen-free copper wire with a silver-plated surface,

the outer conductor is a seamless oxygen-free copper pipe.