矩形隧道中电磁波传播模式的分析

隧道中环境复杂,对电磁波传播特性的研究比较困难.使用软件模拟方法可以实现对连续变化环境中电磁波传播特性的研究,克服了理论研究和实验方法的局限性.研究结果显示:矩形隧道电磁波的传播,是由多种模式共同作用的结果.近场区高次模起主要作用,信号波动剧烈,远场区低次模起主要作用,信号波动平缓.水平极化电磁波的衰减小于垂直极化电磁波的衰减;靠近隧道壁的信号比位于中央位置的信号有更大的衰减和波动.

Analysis of electromagnetic wave propagation modes in rectangular tunnel

The tunnel environment is so complex that the study on the characteristics of electromagnetic waves propagation in a tunnel is very difficult. Based on the software simulation method, electromagnetic wave propagation modes in a rectangular tunnel were analyzed. The results show that a tunnel radio signal consists of a summation of many propagation modes. In the near field region, there are more significant higher-order modes that cause sharp fluctuation, in the far field region, lower-order modes, especially the dominant mode, act as the important role. The attenuation of the horizontal polarization electromagnetic wave is less than that of the vertical polarization electromagnetic wave. The signal of the spot near tunnel walls causes more attenuation and sharper fluctuation than that of the center tunnel.