Perturbation Theory for a Biisotropic Sample in a Cavity Resonator with Applications to Measurement Techniques

Resonator measurement techniques for exploring electromagnetic parameters of of biisotropic (non-reciprocal chiral) materials are discussed. The biisotropic materials are the most general linear isotropic materials and the corresponding constitutive relations are governed by four complex material parameters. The theory of resonator measurement techniques, based on the perturbation analysis, is developed. It is shown that the complex permittivity, permeability and the non-reciprocity (Tellegen) parameter of a small sample can be determined by measuring resonant frequency shifts in a rectangular resonator. To measure the non-reciprocity parameter, a method utilizing a rectangular resonator with two degenerated modes is proposed.