Dual-band polarization conversion based on non-twisted Q-shaped metasurface

In this paper, we theoretically and experimentally report an achiral dual-band metasurface with linear birefringence. The unit cell of the achiral metasurface consists of non-twisted Q-shape metallic ring resonators with a stub breaking the rotational symmetry. Moreover, due to the presence of the stub, we find the proposed metasurface emits dual-band circularly polarized wave with low transmission loss and high polarization extinction for a normal incident y-direction linearly polarized wave. We also systematically investigate the dependence of the electromagnetic response of the proposed structure on the geometric parameters. It is hoped that the proposed simple, easily fabricated model of achiral metasurface can be used in further polarization control applications