Theory of the radio wave propagation in railway trains

Radio waves have found applications for communication and control in modern railway operations. This paper concentrates on characterising radio wave propagation in trains. For this purpose, an oversized imperfect periodically loaded rectangular waveguide is proposed, and the surface impedance approximation is adopted to formulate the problem. The theoretical results show that HEMq,mn and TSMq,m0 modes can propagate. Meanwhile, why TSEq,m0 modes can not exist is also proved. The closed-form propagation constants for those important TSMq,m0 modes are obtained. The numerical results for the propagation attenuation of the dominant TSM1,10 are presented. The influence of passengers on propagation is discussed.