This paper is a review tracing the development of superconductive communication cables.
A 1.6mm superconductive coaxial line constructed of Pb conductors and FEP dielectric has been developed, which has the characteristic impedance of 50±0.3 ohms and the attenuation of about 0.6dB/Km at 1GHz and 4.2K. The attenuation up to 4GHz is mainly due to dielectric losses.
Superconductive coaxial lines are arranged in a helium conducting tube and refrigerated by liquid helium. The helium tube is insulated thermally from room temperature environment by multilayer insulators, shield conductors and vacuum space.
At present, the total heat inflow into cryogen in the refrigerant conductor is about 100W/Km.