A Reconfigurable Polarization Converter Based on Active Metasurface

We present a reconfigurable polarization converter which is composed of an active metasurface and a dielectric plate backed with metallic gratings. The unit cell of the active metasurface is a butterfly-shaped structure embedded with voltage controlled varactor diodes. By controlling the bias voltage of the varactor diode, the proposed polarization converter is able to switch its functions between linear polarization converter and circular polarization converter. For biased voltage of OV, the proposed device acts as a linear polarization converter; whereas for the bias voltage of -19 V, it is switched to be a circular polarization converter.