Dispersion of the dielectric Frohlich model and mixtures

The dispersion mechanism of the dielectric Fröhlich model is first analyzed. The frequency dependence of the effective permittivity of a two-phase Fröhlich composite is then modeled and derived based on the classic Maxwell Garnett mixing rule. The changes of the dispersive model parameters due to the mixing are analyzed and specified. According to these results, the influence of dispersive behavior of individual phase on that of Fröhlich mixture is such that, depending on the volume fraction, the composite follows either a double-Debye-type dispersion or a more complicated model which combines a Lorentz-type, a shifted passive Debye-type and a shifted active Debye-type dispersions.