Radio propagation along a coupled mode leaky coaxial cable in tunnels

This paper deals with the propagation of UHF radio signals along a coupled mode leaky cable in tunnel environments. In the study we model the coupled mode cable as a long electrical antenna. We simulate the distribution of the received signal level excited by the cable in free space, over the half plane, and in a tunnel. It is found that the received signal levels are fluctuated in the region near the cable and dropped gradually in the region far away from the cable.