Loop Antennas for Underwater Communications

In this paper, the performances of circular loop antennas for underwater communication, designed to work both in freshwater and seawater, are analyzed. Firstly, the attenuation and wavelength in both environments are evaluated with the goal of selecting the proper working frequencies, that are supposed to be 433.92 MHz in freshwater and 10 kHz in seawater. Secondly, several antenna configurations with different size are designed and the results obtained with numerical simulations are presented, comparing some performances. Moreover, a comparison of the transmission coefficient behaviour with the distance between two loop antennas both in freshwater and seawater is provided.