Polarization Agility Using A Microfluidically Reconfigurable Metasurface

This paper presents a microfluidically reconfigurable metasurface for polarization switching. A 5 × 5 unit cells metasurface array acts as a superstrate layer on the top of a circularly polarized antenna. The square split ring resonator with cross-shaped microfluidic channels can be reconfigured by pneumatically injecting or removing liquid metal alloy into 3D printed channels in two orthogonal directions. The incoming circular polarized (CP) wave can be either converted into a linearly polarized (LP) wave or transmitted without any effect as a CP wave. The simulated return loss plots for CP-CP and CP-LP conversion exhibit good impedance matching from 4.5 – 4.9 GHz, which represents a fractional bandwidth (FBW) of 8.5%. The far-field realized peak gain for both states remains greater than 6 dBi. The common bandwidth of CP-CP and CP-LP conversion is 4.5 –4.7 GHz resulting in FBW of 4.3%. The proposed metasurface antenna can be used in MIMO systems and biomedical applications to reduce polarization mismatches and multipath fading.