Polarization-insensitive planar left-handed metamaterials

In this paper, we propose a new kind of four-fold symmetric planar left-handed metamaterial (LHM) which consists of a cross and a ring. The results demonstrate that the left-handed metamaterial has a pass band at around 12.79GHz. Negative refractive index realizes with both negative permittivity and negative permeability over the same frequency. Also S-parameter retrieval method is used to extract effective permittivity, permeability and refractive index. Refractive index below zero extends from frequency of 12.43GHz to 13.64GHz. At last, transmission properties with different polarizations of incident EM waves are discussed which verify the polarization-insensitive left-handed metamaterial.