Profile inversion of spherical objects illuminated by TE- and TM-polarized waves

A new technique for inverting the radially dependent permittivity profile in spherical dielectric objects illuminated by TE- or TM-polarized waves is presented. The technique is based on a generalization of the well established Fourier transform method used for reconstructing permittivity profiles in planar stratified media in conjunction with a previously proposed renormalization technique to obtain a unique solution of the involved nonlinear problem. The unknown permittivity profile is reconstructed in terms of a spherical Fourier-Bessel transform of the measured reflection coefficient data in conjunction with a numerical transform. A number of reconstruction examples has been considered and an excellent agreement between original and reconstructed profiles has been achieved even for very high values of permittivity.