A linear-to-circular polarization converter with half transmission and half reflection using a single-layered metamaterial

A linear-to-circular polarization converter with half transmission and half reflection using a single-layered metamaterial is theoretically and numerically demonstrated. The unit cell of the metamaterial consists of two coupled split-ring resonators with identical dimensions. A theoretical analysis based on an electrical circuit model of the coupled split-ring resonators indicates that the linear-to-circular polarization converter is achieved when the magnetic coupling between the split-ring resonators is set to a certain strength. A finite-difference time-domain simulation reveals that the single-layered metamaterial behaves as the linear-to-circular polarization converter and that the polarization converter has the combined characteristics of a half mirror and a quarter-wave plate.