Patent ID: 7877059
Filing Date: 2011-01-25
Classification: H04B,Y10S

Abstract:
1. An underwater communications system comprising: a transmitter which transmits electromagnetic and/or magnetic signals and a remote receiver said transmitter comprising a data input, a modulator for modulating the input data onto a carrier signal and an electrically insulated, magnetic coupled antenna for transmitting said modulated signals, at least one of said transmitter and said remote receiver being underwater said system further comprising at least one intermediate transceiver comprising an intermediate receiver and an intermediate transmitter, said intermediate transceiver being operable to relay a signal from said transmitter to said remote receiver via electromagnetic and/or magnetic signals, wherein communications between said transmitter and said intermediate receiver or communications between said intermediate transmitter and said remote receiver takes place within a near field of said electromagnetic and/or magnetic signals of said transmitter or said intermediate transmitter, said near field corresponding to the region where at least one of inverse distance squared (1/r