Advances in planar and volumetric metamaterials

We present two recent advances in the area of electromagnetic metamaterials. The first is the development of 2D transmission-line (TL) based metamaterials with arbitrary tensorial effective material parameters. These new metamaterials are distinct from earlier TL metamaterials which were limited to having effective material parameters that are diagonal in the Cartesian basis. The second advance is the development of a 3D isotropic negative refractive index metamaterial. The volumetric metamaterial exhibits an isotropic response for all polarizations and angles of incidence.