Equivalent analysis method of electromagnetic waves propagation in semi-circular arched tunnel

Abstract：Attenuation of electromagnetic waves propagation in a semi-circular arched tunnel can not be found accurately by means of the classical theory method.Based on the equivalent analysis method, the lowest attenuation mode of semi-circular arched tunnel was compared with the lowest attenuation modes of rectangular tunnel and circular tunnel.The result indicates that, at 900 MHz, the error rate of a semi-circular arched tunnel equaling a rectangular tunnel with the same values of the width and the height is very low, the attenuation curves are very close to each other, and the equivalent analysis method is proved feasible.

Keyword：semi-circular arched tunnel;electromagnetic wave;lowest attenuation mode;equivalent analysis method