在矿井巷道、地铁隧道等类似限定空间中的通信受巷道壁粗糙度、电导率、空气湿度等因素影响，与地面上通信相比有着较大差别。精确描述限定空间中(矿井巷道)的通信，对其通信调度至关重要。基于分段思想对巷道电磁波传播特性进行了研究，将电磁波传播区域分为自由空间区、多模传播区、基模传播区、极远区，得到近场区电磁波传播机制的分界点，有助于实现对巷道电磁波传播机制的预测。在研究矩形巷道中电磁波传播机制分界点时，针对4种典型尺寸的巷道，通过不同巷道载波频率变化试验的测量及电磁仿真软件Wireless Insite建立巷道电磁波传播模型，改变传输频率得出不同的试验结果。结果表明：在矩形巷道中载波频率为900～2 700 MHz条件下，随着收发天线载波频率的增大，电磁波在近场区中的分界点值逐渐减小，受安装天线极化作用影响较小。

Communication in mine roadways, subway tunnels and other similar restricted space is greatly affected by factors such as wall roughness, electrical conductivity, air humidity and other factors. Compared with ground communication, there is a big difference. Therefore, it is very important to accurately [JP3]describe the communication in the restricted space. Based on the segmentation idea, the electromagnetic wave propagation characteristics in the roadway were studied, and the electromagnetic wave propagation area is divided into free space area, multimode propagation area, fundamental mode propagation area, and extreme far area. It is helpful to obtain the demarcation point of electromagnetic wave propagation mechanism in the near field area to realize the prediction of the electromagnetic wave propagation mechanism in the tunnel. When studying the demarcation point of electromagnetic wave propagation mechanism in rectangular roadways, aiming at 4 types of roadways of typical sizes, electromagnetic wave propagation models in the roadway were established through measurement of different roadway frequency variations and electromagnetic simulation software Wireless Insite, and different results were obtained by changing the transmission frequency to obtain the received power. The results show that in the rectangular roadway, when the carrier frequency is from 900 MHz to 2 700 MHz, with the increase of the carrier frequency of the transceiver antenna, the demarcation point value of the electromagnetic wave in the near-field region gradually decreases, which is less affected by the polarization of the installed antenna.

0 引言

1 电磁波的传播模型

   1.1 近场区分界点的划分

   1.2 自由空间传播

2 试验验证与分析

   2.1 测试巷道1的试验与分析

   2.2 测试巷道2的试验与分析

   2.3 测试巷道3的试验与分析

   2.4 巷道4的仿真与分析

3 结论