Abstract: A coaxial cable structure for electrical signal transmission at frequencies up to the microwave region. The center conductor may be a conventional metallic conductor and the dielectric material between the center conductor and the outer coaxial shield conductor and the outer coaxial shield conductor may be conventional polyethylene or polytetrafluoroethylene. The outer conductor is formed over the dielectric layer acting as a mandrel by means of emplaced, small diameter carbon fibers stabilized in place by an impregnating resin. Use of a curable resin forms the cable rigidly. A variation employs braided carbon fibers without curable resin.