Low attenuation high frequency coaxial cable for microwave energy in the gigaHertz frequency range

摘要

A low attenuation high frequency coaxial cable is provided for carrying microwave energy in the gigaHertz range. A center conductor is wrapped with a plurality of layers of low density PTFE dielectric material. At least one layer of high density unsintered PTFE dielectric material is tightly wrapped around the low density tape with overlapping edges and then is sintered for forming an envelope strong enough to hold the low density material in position during the remainder of the cable preparation and during an attaching of terminating connectors. An outer conductor of longitudinally extending, parallel, adjacent electrically conductive wire strands is applied with a slight helical lay around the dielectric of the cable along its axis thereof surrounding the high density tape. A serving may be applied over the longitudinal wire strands and a jacket applied around the cable over the serving. The cable so formed provides an improvement in performance. After heat curing of the cable, it may be improved further by providing a tight wire braid around the jacket which again is provided with another outer jacket. The serving may be omitted, and then the jacket of unsintered high density PTFE is applied around the wire strands of the outer conductor. This jacket is sintered, and then a wire braid is applied tightly over the sintered jacket.