Numerical Modeling of Periodic Composite Media for Electromagnetic Shielding Application

Abstract

This paper describes a methodology to extract effective electrical properties for periodic composite medium. The extraction algorithm is based on a periodic finite-difference time-domain (FDTD) method. The results are compared with conventional mixing theories and 3D Fourier series expansion methods. Two results show satisfactory agreement. With the extracted effective permittivity and conductivity, one can readily use these parameters to study electrical properties of composite materials with arbitrary micro-geometry and the shielding effects of using composite materials.

Effective Permittivity of 3-D Periodic Composites With Regular and Irregular Inclusions

“…The most common simplification is to consider regularly-shaped inclusions and sometimes a 2-D projected structure is analyzed. In the time domain, the effective permittivity has been calculated in 2-D for random mixtures using finite difference time-domain (FDTD) simulation [6] (where inclusions are disks), [7] (disks, regular polygons and fractals), and 3-D random mixtures using FDTD [8] (spheres, crosses and regular polyhedrons), and [9] (spheres and a complex yet symmetric structure). With timedomain EM analysis, regular shapes, such as cubes, spheres, and regular polygons have been studied because these enabled simplified gridding using rectangular meshing (and analytic projections onto a rectangular mesh in the case of spheres).…”

Electromagnetic Properties of Disordered Three-Dimensional Mixtures

“…Studies of effective medium properties have used various simulation methods. The effective permittivity of a mixture has been calculated using finite difference time-domain EM simulation in two dimensions [1], [2] and three dimensions [3], [4], in two dimensions using frequency-domain finite element EM analysis [5], and in three dimensions using the frequency-domain finite difference [6]- [8] and finite element [9]- [11] methods.…”