Research on low-loss and high-speed seabed propagation model for underwater Radio-Frequency-Electromagnetic communication

The mainly limitation of the development of underwater Radio-Frequency-Electromagnetic (RF-EM) wireless communication is severe attenuation introduced by the seawater characteristics of high permittivity and high conductivity. Fortunately, in previous studies, it was found through experiments that the loss between two underwater antennas near seawater surface or seabed is much smaller than the higher order severe attenuation for the line of sight (LOS) path in seawater. But no one has given reasonable explanation for this phenomenon. To solve this problem, we investigate the propagation mechanism of this phenomenon theoretically. An alternative seabed propagation model based on evanescent wave effect generated by the total reflection on the seabed-rock-layer surface is proposed in this paper. Then we analyze the performance of this model according to Goos-Hanchen (GH) Shift of evanescent wave. Simulation results show that the propagation loss in this model is about 1/20 of that in seawater and the propagation velocity can be increased by 20 times. Proposed technology is expected to become an important part of underwater high-speed and reliable communication and deep-sea development.