Analysis of electromagnetic wave propagation characteristics in rectangular tunnels based on the geometrical optics method

Propagation characteristics of electromagnetic wave in rectangular tunnels are studied using the geometrical optics method. The relation between the power of the receiving antenna and the propagation distance is analyzed. The results indicate that the received power becomes less with the increase of the propagation distance. The more the height´s difference between the sending and receiving antenna, the farther the propagation distance will be, the more similar between the curve obtained by the geometrical optics and the curve under the single mode; the further the electromagnetic wave is transmitted, the more difference of the receiving power there are. And results of them are compared with the ones in single mode. The results of geometrical optics method are more consistent with actual condition.