A Circularly-Polarized-Reconfigurable Patch Antenna With Liquid Dielectric

A circularly-polarized-reconfigurable patch antenna based on fluidic control method is proposed in this paper. liquid dielectric, ethyl acetate, introduced to change the substrate of a from homogeneous inhomogeneous. Two orthogonal fundamental transverse magnetic (TM) modes are excited with 90° phase difference order produce circularly polarized (CP) radiation. Then, polarization switchable between left-hand circular (LHCP) and right-hand (RHCP) through injection dielectric different channels substrate. For demonstration, designed at 2.4 GHz for radio frequency identification (RFID) application. According measured result, circular-polarization-reconfigurable has stable gain 8 dBic an efficiency 90 % across effective band. Additionally, overlapped impedance bandwidth two state 2.24 2.52 which can fully cover 3-dB axial ratio (AR) 2.38 2.43 GHz.