A Switchable Linear-to-Circular Polarizer Based on Varactor-loaded Metasurface at 30 GHz

In this paper, a switchable linear-to-circular polarizer based on varactor-loaded metasurface is proposed. With an incident 45° linear polarization (LP) plane wave, the polarization of the transmission wave through this polarizer can be switched between left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) by controlling the bias voltage of the varactors. Simulation results show that the designed polarizer exhibits transmission losses better than -1 dB, and 3 dB axial ratio bandwidth of LHCP and RHCP is 1.7GHz (or 5.7%) and 1.5GHz (or 5%), respectively.