A Seawater Antenna for Emergency Applications

This work proposes a liquid antenna made with seawater for UHF emergency marine communication. Thanks to the high conductivity of seawater, it is possible to consider it a good conductor. Moreover, thanks to the high dielectric permittivity of seawater, the electrical length of an antenna can be reduced by tens of times. Thanks to these characteristics, it is possible to design compact, light, and efficient antennas. In this work, we proposed a seawater antenna for maritime UHF communication. The antenna body is realized with a column of seawater created using a small pump. By adjusting the column height, it is possible to change the antenna's resonance frequency, resulting in a liquid-reconfigurable antenna. Coupling with the radio frequency front end is achieved with a magnetic coupling. A simple prototype has been designed and experimentally assessed, providing satisfactory results.