Abstract-In this paper, the electric voltage of a single-layer ho-mogeneous and anisotropic composite material has been calculated developing a mathematical model based on the diffusion equation . The proposed model has based developed assuming the minimum wavelength of the source much longer than the greatest dimen-sion of the analyzed structures and charge relaxation time of the composite material smaller than any allowable rise time of field source. Thefinite-differrnce time-domain method,based on an explicit