Coax

Abstract

Being positioned between inner conductor and outer conductor, the insulator is in shape of corrugated pipe. Being composed of thermoplastic fluoride bearing resin, the insulator includes an insulated layer and insulated ribs. The insulated layer includes a circumference face cladding the inner conductor. Insulated ribs are extruded from the insulated layer along radial direction, and are contacted to outer conductor. The insulated ribs possess continuous shape in axial direction. Three more insulated ribs are distributed along circumferencial direction discretely in each other.

Description

technical field [0001] The present invention relates to a coaxial cable, and more particularly, to an insulator portion interposed between an inner conductor and an outer conductor, and the structure of the outer conductor. Background technique [0002] The insulator is placed between the inner and outer conductors of the coaxial cable. There are many types of insulators, and conventionally known ones include those made of PTFE (PoliTetraFluoroEthylene), which is a non-thermoplastic fluororesin, or those made of PFA (PerFluoroAlkoxy), which is a thermoplastic fluororesin. [0003] When the insulator is made of PTFE, which is a non-thermoplastic fluorine-containing resin, the dielectric properties (dielectric loss tangent) can be maintained at a high level, but it is difficult to manufacture coaxial cables by an inexpensive manufacturing method such as continuous molding and extrusion. Manufacturing costs rose. [0004] When the insulator is made of PFA which is a thermopla...

AI Technical Summary

Problems solved by technology

However, the mixing of foaming agent into PFA itself becomes the main cause of deterioration of dielectric properties (dielectric loss tangent) of insulator (PFA)

Therefore, in order to make the dielectric loss tangent of the insulator (PFA) equal to that of the insulator (PTFE), it is necessary to make the expansion rate more than 80%, but this expansion rate cannot be realized as an industrial product.

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