Further investigation on water antennas

Abstract

Water antennas are a special type of antennas and have attracted limited attention so far. In this study, a monopole water antenna with a dielectric layer is chosen as an example to study some less obvious characteristics of the water antenna. The resonant frequency, radiation efficiency and fractional bandwidth are of particular interest. Firstly, the effects of the dielectric layer between the water and the ground plane are studied. The results show that this layer has a crucial effect on the antenna resonant frequency and radiation efficiency. Secondly, the water with different conductivity is investigated. With different conductivity, the antenna may be regarded as a dielectric resonant antenna, a conducting antenna or their combination. Thirdly, a water antenna with a supporting structure is fabricated for validation. Measurements are conducted in an anechoic chamber and a reverberation chamber to evaluate its performance as a function of various parameters. Finally, the water temperature electromagnetic characteristics are investigated. Good agreements are achieved between the simulation and measurement results. It is shown that this type of antenna shows better performance than the conventional antenna in aspects such as broadband, cost, reconfigurability, transparency and it can be a promising candidate for a range of applications.