Effective permittivity of layered dielectric sphere composites

A straightforward model is presented for analysing the effective permittivi ties of layered dielectric sphere composites. Using the present model, the effective permittivity, epsilon(eff), Of layered dielectric sphere composit es can be deduced using classical two-phase dielectric mixture formulae in two steps: first, the effective permittivity, epsilon(incl), of the inclusi ons is calculated by taking the layered dielectric sphere inclusions as sub -composites; and second, the effective permittivity, epsilon(eff), of the c omposites is found by substituting the layered dielectric sphere inclusions with homogeneous spheres whose permittivity is equal to epsilon(incl). The present model is applicable to multi-layer sphere composites. Experiments on resin-based hollow bead composites show that the present model accuratel y predicts the effective permittivity of layered dielectric sphere composit es. (C) 1998 Kluwer Academic Publishers.