Propagation Character of Electromagnetic Wave of the Different Transmitter Position in Mine Tunnel

In order to analysis the propagation character of electromagnetic wave in the limited space of mine tunnel when the wireless sensor is set in different position, the electric-field intensity and magnetic-field intensity of horizontal polarization wave are obtained according to Maxwell equation and boundary condition of tunnel. The electric-field attenuation coefficient of horizontal and vertical polarization wave are deduced through the traveling-wave condition of limited space. The attenuation characters of different position transmitter in rectangular mine tunnels are simulated in an experiment tunnel.The results shows the attenuation of electric-field intensity is increase quickly in 50 m. When the transmitter is more close to the wall of the mine tunnel, the mode of propagation is more complex and the attenuation is more serious, whereas in the middle of the mine tunnel, the attenuation rate of radio is the least. It is benefit to evaluate the channel of wireless sensor network in mine tunnel.