Dispersion analysis of resonance cone behaviour in magnetically anisotropic transmission-line metamaterials

We apply a periodic dispersion analysis to the study of two-dimensional, anisotropic transmission-line (TL) metamaterials that, although electrically isotropic, possess magnetic anisotropy in the effective medium limit. It is shown that these structures can be designed to exhibit hyperbolic dispersion surfaces in phase space, and resonance cones, akin to those observed by K.G. Balmain et al., in real space. Full-wave simulations demonstrate that these resonance cones can be made to refract negatively at, and to focus through, an interface between two anisotropic TL metamaterials whose axes are mutually transposed by 90 degrees.