Abstract: As a coaxial cable includes a dielectric layer around a center conductor, an outer conductor layer around the dielectric layer, and a sheath around the outer conductor layer, wherein the dielectric layer is made of unsintered polytetrafluoroethylene, and a metal foil imparting an increased shielding effectiveness and shape maintainability is provided between the dielectric layer made of the unsintered polytetrafluoroethylene and the outer conductor layer, it is possible to make it a high frequency coaxial cable which, having a very excellent low insertion loss, and also having a high shielding effectiveness against a signal leakage increasing an attenuation, can be bent easily and freely by hand without using a tool or the like while effectively maintaining an electrical characteristic for a high frequency signal and, after being bent, has an excellent shape maintainability in that bent condition, enabling an easy wiring work or connecting work by virtue of the excellent shape maintainability.

Abstract: A transmission line is provided, at least a portion of the wave energy transmitting part of the line being made of a dielectric material shaped to create a physical condition which preserves the deflected wave surface of the electromagnetic wave along the portion of the transmission line. The physical condition for preserving the deflected wave surface is formed by providing at least one linear portion which retards the speed of energy transmission so as to prevent the rotation of the electric field surface of the electromagnetic wave. The wave energy transmitting portion composed of dielectric material is preferably made to have an oval cross-section in which the ratio between the major axis and the minor axis has a value not lower than 4/3. Alternatively, the wave energy transmitting portion can be made to have a rectangular cross-section.