Dielectric resonance in composites filled with metal-coated microspheres

Using formulas obtained from the first-order solutions of Mie theory in an effective medium approach, several example computations of bulk permittivity of a composite are given in different cases of layered spherical inclusions dispersed in a matrix. It is theoretically shown that a simple, isotropic negative-permittivity composite material could be constructed by suitable choice of geometrical and dielectric parameters of the constituents.