Characterization of metamaterial slabs in terms of scattering parameters under oblique plane wave incidence

In this work, a retrieval procedure which allows the determination of equivalent dyadic permittivity and permeability of metamaterials from reflection and transmission coefficients obtained for several incidence directions and polarizations is presented. The main goal is to determine to which extent a model of anisotropic homogeneous material can be applied to specific metamaterials. Preliminary results on wire media and arrays of magnetic resonators show that a certain level of symmetry in the unit cell is required to avoid bianisotropy, and that small unit cells compared to the wavelength are favorable for such a homogenization.