HF signals transmission system - between stationary equipment and vehicle moving along track uses coaxial cable with metal rails

摘要

The signal transmission system uses a coaxial radiating h.f. cable which consists of an inner and an outer conductor, which are separated by a layer od dielectric material. The cable is laid parallel to the track on which the vehicle runs and there are metal rails running along the cable. The outer conductor of the h.f. cable (6) is connected with the metal rial (1) at several points along its length and the spacing between these points is less than half the wavelength of the highest frequency to be transmitted through the cable. An aerial (5) on the vehicle is used to pick up signals by induction.