Electromagnetic wave propagation in a two‐dimensional tunnel with a modified cross‐junction

Abstract

This paper investigates theoretically and experimentally the electromagnetic wave propagation in a two‐dimensional tunnel with a modified cross‐junction in connection with radio communications in tunnels, underground, urban areas with high‐rise buildings and others. Modal expansions and Fourier transform are used as an analytical method, and the surface impedance model is employed as a boundary condition on the tunnel walls. The results presented here can be applied to special tunnels such as the T‐type, modified T‐type, L‐type and step‐type. Experiments based on a microwave simulation are performed by using tunnels composed of concrete slabs. It is found that, concerning electric field intensity, experimental and theoretical results agree well.

Proposal of design method for fixed wireless telecommunication in 400-MHz band and measurements of propagation inside office buildings

“…Consequently, it is expected that if L and P(0) are measured for each building, the design for the propagation loss in the building will become valid in general [8,11,12]. The reason that the central value of the received power level is not inversely proportional to the distance may be that the effects of reflection and transmission of the interior materials of the wall, ceiling, and floor, as well as the furniture, are dominant over the effect of radiation, as in attenuation in a tunnel [6].…”

“…There are reports on electromagnetic wave propagation characteristics in space in many frequency bands, such as the propagation loss as a function of the distance in a corridor [6] and the penetration loss from an outdoor base station. There are only a few reports on the relationship between propagation loss and transmitterreceiver distance in an office environment with furniture [79].…”