A Wideband Polarization-Reconfigurable Water Dielectric Resonator Antenna

A water dielectric resonator antenna with reconfiguration and broadband characteristics is presented. By injecting pure water into various cavities of the Plexiglass holder, the antenna can be switched among left-hand circular polarization, right-hand circular polarization, and linear polarization in almost the same operating frequency range. With the high relative permittivity, water acts as a dielectric resonator as well as an interface similar to electric wall to form a broad axial-ratio bandwidth. Thus, a broad usable bandwidth is measured to be over 22%, and the measured radiation efficiency and realized gain centralize in 60%-70% and 3-4 dBi, respectively.