Effect of antenna on propagation characteristics of electromagnetic waves in tunnel environments

Abstract

The optimal radiation pattern and optimal position of the source antenna installed inside a tunnel is the concern of this paper. By comparing theoretical and experimental results, it is shown that the field distribution of the electromagnetic wave in tunnel environments is sensitive to the position of the transmitting antenna in the cross section of a tunnel. And compared with the Omni-directional antenna, the utilization of the vertical antenna with radiation pattern of sinn θ on the upper middle of the wall, or the horizontal antenna with radiation pattern of sinn ϕ on the middle of the side wall, could represent significant improvement of the standing wave graphics, as well as the propagation attenuation.