Preliminary results on cylindrical antennas for underwater communication

In this paper, we investigate the possibility of using cylindrical antennas for short-range underwater communication in freshwater. The performances of three types of cylindrical antennas are compared: dipole, monopole and folded dipole. In freshwater the wavelength is 9-10 times lower than in free space at a specific frequency. This allows a reduction of the antenna actual length and therefore the possibility to work at lower frequencies, where the attenuation introduced by the water is lower, too. The dimensions of the three cylindrical antennas are derived using a well-known analytical model. The antennas have been designed and simulated to work in ISM 433MHz frequency band.