Leaky coaxial cable for communication in high speed railway transportation

The practical performance of leaky coaxial cables is affected by the surrounding materials. Coupling loss and transmission loss vary according to the distance between a concrete wall and the cable. Some experiments were conducted using concrete walls on an experimental railway, and several kinds of installation methods were tested. It was confirmed that the effect of snow was small. It is also shown that the newly developed antenna, the main beam of which had the same directivity pattern as that of the leaky coaxial cable, was very effective in reducing coupling loss and fluctuation of received power.