Negative refraction and cross polarization effects in metamaterial realized with bianisotropic S-ring resonator

The refraction and propagation properties of left-handed materials with bianisotropic effects are investigated. We show that the dispersion relation of the material is strongly influenced by the inclusion of chirality; therefore, different refraction behaviors are observed corresponding to different values of the chirality. A realization of the bianisotropic left-handed material based on the structure of S-ring resonators is further proposed. By subtly shorting some horizontal metallic strips inside of the ring, magnetoelectric coupling is raised, leading to a bianisotropic effect in this artificial medium. The structure is theoretically analyzed from a microscopic viewpoint, and then the macroscopic constitutive parameters are presented, where a nonzero chirality component is clearly shown. Numerical simulation shows that there exists strong cross polarization effects when waves are incident onto a slab of this material, further confirming the results predicted by our theoretical analysis.