Two-dimensional analysis of composite structures by the finite-difference time-domain method adopting scaling approach [EM shielding]

In this paper, the electric voltage of a single-layer homogeneous and anisotropic composite material has been calculated developing a mathematical model based on the diffusion equation. The proposed model has been developed assuming the minimum wavelength of the source much longer than the greatest dimension of the analyzed structures and the charge relaxation time of the composite material smaller than any allowable rise time of the field source. The finite-difference time-domain method, based on an explicit scheme, has been used to solve the differential equations and a scaling approach has been adopted to reduce computing time. The obtained results carried have been compared with those obtained simulating an equivalent electrical circuit network using SPICE. A good agreement between these two methods has been observed.