A Fan-Shaped Compact Water Antenna With Wide Bandwidth and Optical Transparence

A novel wideband and compact water antenna with optically transparent characteristic is presented in this communication. This antenna mainly consists of a fan-shaped cylindrical radiator, a top disk, a cylindrical base, and a water reflector. Based on two resonant modes, this antenna can achieve wideband characteristic. Meanwhile, when combined with fan-shaped radiator and top disk loading, the overall dimensions can be greatly reduced without compromising impedance matching. The ground made of distilled water is used for full transparency. The proposed antenna covers frequency range from 1.16 to 2.79 GHz for
$S_{11} < -10$
dB. As far as we know, the proposed antenna shows the widest relative bandwidth (82.5%) in the field of transparent antennas, without sacrificing size and radiation performance.