Asymmetric transmission with double bands based on chiral twisted double-split-ring resonators

A bi-layered chiral structure with double split-ring resonators is proposed to achieve dual-band asymmetric transmission of linear polarization waves propagating forward and backward. Moreover, according to the theoretical and numerical results, this designed chiral metamaterial can achieve the asymmetric transmission of both linearly and circularly polarized waves, in contrast to previously reported chiral structures that can realize asymmetric transmission of either linearly or circularly polarized waves only.