Development of method to extend radio wave communication range under the sea

Since the radio wave is rapidly attenuated in the seawater, the radio wave communication has not been applied to the underwater communication. However, the radio wave communication in the seawater can be realized by placing a dielectric material as a propagation path between watertight cases which contain a transmitter and/or a receiver. This radio wave communication method in the seawater is proposed by authors. The proposed method is only used for a short distance communication because the attenuation of a dielectric material is still large compared with the air. In order to apply the proposed method to underwater systems, the extension of the communication distance is desired. The major factor of the attenuation is considered the radio wave propagation into seawater from the propagation path. It is known that the radio wave cannot penetrate a metal foil or a wire netting. Therefore, the attenuation of the radio wave can be decreased by covering the propagation path with the metal foil or the wire netting. In this paper, the communication property is analyzed how the communication range can be extended by covering the propagation path in the metal foil or the wire netting.