Optimization approach to the retrieval of the constitutive parameters of a slab of general bianisotropic medium

Abstract

The reconstruction of the frequency-dispersive constitutive parameters of general bianisotropic media is achieved by an optimization approach. The constitutive parameters are optimized in order to match the measured reflection and transmission data for plane wave incidence onto bianisotropic slabs. Two optimization methods, in our case the differential evolution (DE) algorithm and the Nelder-Mead simplex method, are used for the reconstruction at low frequencies. The Nelder-Mead simplex method is then used to obtain the solutions at higher frequencies, where the initial guess is obtained by the linear extrapolation of the solutions at previous frequencies. The proposed reconstruction method is tested with both noiseless and noisy data, and is proven feasible and robust.