Boundary Effects on the Determination of Electromagnetic Properties of Bianisotropic Metamaterials From Scattering Parameters

A retrieval method is proposed for determination of electromagnetic properties of bianisotropic metamaterial (MM) slabs involving boundary effects from electric and magnetic surface susceptibilities. To achieve this, we derived two characteristic functions for wave impedances by the application of generalized sheet transition conditions from which electromagnetic constitutive parameters are determined using scattering (S-) parameters of a pair of slabs with different lengths. We applied our method for extraction of electromagnetic parameters of an Ω-shaped MM slab. From our analysis, we noted the following main results. First, when compared with other methods that do not consider boundary effects, we noted that our method retrieves reference-plane-invariant and thickness-independent electromagnetic properties provided that higher order wave interactions at interfaces are negligible when considering two separate pairs of MM slabs differing by the same length and when the accuracy of simulations (meshing size) is improved. Second, extracted constitutive parameters are in good agreement with the locality conditions over which our model is constructed. Third, extracted electric surface susceptibilities at interfaces are correspondingly greater than magnetic surface susceptibilities due to strong electric resonance of the Ω-shaped MM slab.