Radiation Pattern and Polarization Reconfigurable Antenna Using Dielectric Liquid

Abstract

A reconfigurable antenna with radiation pattern and polarization reconfiguration capabilities is investigated in this communication. The antenna consists of a central dielectric resonator antenna (DRA) and two parasitic DRAs made of a liquid solution with low dielectric loss. Utilizing the flowing of liquid, the existing of parasitic DRA can be changed to produce different patterns. An omnidirectional pattern can be realized when only the central DRA radiates, while a unidirectional pattern can be obtained using the parasitic DRAs. Furthermore, the polarization of the antenna with unidirectional radiation can be changed by forming different parasitic DRAs, which can be realized via liquid flowing. Based on this principle, three different radiation states, namely, omnidirectional radiation and unidirectional radiation with $x$ - or $y$ -polarization, can be obtained. To verify the design, a prototype of the antenna operating at 2.4 GHz was simulated, fabricated, and measured. The measurement results indicate that the antenna provides effective impedance matching over the band of interest as well as radiation pattern and polarization reconfiguration capabilities.