Robust technique for the polarisability matrix retrieval of bianisotropic scatterers via their reflection and transmission coefficients

A consistent algorithm for extracting the polarisability matrix of bianisotropic meta-atoms directly from their reflection and transmission properties is introduced in this study. Considering a two-dimensional periodic distribution of the scatterer under study, illuminated by properly-polarised, normally-incident, plane waves, the point-dipole approximation is successfully applied in order to analytically compute the scattered field of the array in terms of the particle polarisabilities. Then, simulated or measured S-parameters can be employed for the inversion of the resulting non-linear system of equations, leading to the desired dynamic polarisability matrix and, especially, the magneto-electric coupling term. Finally, the featured technique is applied to an assortment of important structures, frequently utilised for various metamaterial applications and the outcomes are extensively compared with previously existing techniques, thus verifying the merits of the novel approach.