Calculations of Complex Dielectric Permittivity of Two-Phase Composite Medium

A new method is developed to treat rigorously the propagation of electromagnetic waves in composite media. An effective, complex wave vector keff ascribed to the composite is found and used to detrmine an effective dielectric constant ?eff (k). This "dynamic" method (unlike the static methods for static electric fields) is not inherently limited to lossless composites but can be applied to treat the media with finite complex permittivity. The problem of wave propagation is solved supposing periodical structures of media and using the Floquet´s and variational techniques. This method implies a priori that the multiple scattering is taken into account. As an example, a two-phase system in which one constituent in the form of spheres or fibres is embedded in a host homogeneous medium is considered.