隧道中UHF电波传播特性的分析

计算了我国不同类型隧道(铁路隧道、公路隧道、北京地铁1号线、盾构法修建的北京地铁4号线)中UHF电磁波的衰减常数,讨论了隧道横截面尺寸、载波频率对电磁波传播的影响,推导出电磁波传播和隧道横截面几何形状的关系,分析了矩形隧道中不同极化方向和电波衰落的关系,这些结论有助于设计隧道无线通信系统.本文中衰减常数是近似解的形式,在UHF频段下衰减常数的近似解与精确解结果符合的很好.

Analysis of Propagation of UHF Radio Waves in Tunnels

In this article,the attenuation of UHF electromagnetic waves in diverse types of tunnels in our country(railway tunnels,highway tunnels,Beijing No.1 and No.4 subways) are analyzed,also,the dimensions of the cross sections of tunnels and the frequency of carrier are the concerns of this paper.The author detrudes the connection between the propagation of the radio wave and the shapes of the cross sections,and the connection between the different polarized waves and the various decline magnitude.The conclusions will give a reference to design the wireless communication system in tunnels.The paper uses the proximate solutions of attenuating constant,and it's feasible to use the proximate solutions which conform with the accurate solutions very well in UHF frquency.