A generic field analysis technique for a liquid antenna along with a novel high-gain structure of water antenna is presented in this article. The antenna design has liquid material as a conducting radiator contained within a tube, placed on a grounded dielectric substrate. This monopole antenna is fed by a coaxial feed, having the radiating pin inside liquid. The antenna is divided into different regions, and boundary conditions are applied to obtain the resultant field equation. The proposed technique is validated using simulated and measured results, with an existing design with seawater as radiator, and helps to predict the E-field of water antenna in advance to be used as a reconfigurable antenna. Parametric analysis is done to achieve the best antenna design, and a high-gain water antenna with gain value of 23:53 dB, resonating at 2:9 GHz having a bandwidth of 1:08 GHz is proposed and fabricated. The high gain is achieved by placing a superstrate on top of the structure at a cavity height of 11 mm. This seawater monopole antenna delivers broad bandwidth with high gain and is an attractive option to be used as a reconfigurable antenna.
K E Y W O R D Santenna design, field analysis, high gain antenna, liquid antenna, water antenna