Asymmetric chiral metamaterial multi-band circular polarizer based on combined twisted double-gap split-ring resonators

Abstract

In this paper, an ultrathin asymmetric chiral metamaterial multi-band circular polarizer using combined twisted double-gap split-ring resonators (DGSRRs) is proposed and investigated. Experiment and numerical simulations are in good agreement, indicating that when a y-polarized wave is incident on this chiral metamaterial propagating along -z direction, the right circularly polarized (RCP) wave is emitted at 5.58 GHz and 9.34 GHz, while left circularly polarized (LCP) wave is excited at 6.41 GHz and 7.65 GHz, in addition to large polarization extinction ratio of more than 18 dB at the four resonant frequencies. The surface current distributions are studied to illustrate the transformation behavior for both circular polarizations.