Liquid Metal Reconfigurable Patch Antenna for Linear, RH, and LH Circular Polarization With Frequency Tuning

摘要

A microstrip circular patch antenna with frequency and polarization reconfigurability using liquid metal is presented. The antenna has a C-shaped slot cut at the center of the patch and reconfigurability is achieved using two putty containers and liquid metal to switch between four different states. Linear polarization (LP) is observed at 5.83 GHz when there is no liquid metal inside the containers. Depositing two liquid metal droplets in the containers yields circular polarization (CP) at 6 GHz. The right-hand CP (RHCP) is obtained when the right-most container is filled, and the left-hand CP (LHCP) is obtained when the leftmost container is filled with the liquid metal. When all containers are filled, LP is observed at 6.15 GHz. For the LP case, the antenna has a measured gain of 2.68 dB when all containers are filled and a measured gain of 3 dB when the containers are empty, and the axial ratios (ARs) are 19.65 dB (filled containers) and 23.74 dB (empty containers). When the LHCP is activated, the gain is 2.44 dB and the AR is 0.54 dB at 6 GHz. For RHCP, the gain is 2.37 dB and the AR is 1.5 dB at 6 GHz.