FDTD simulation of shielding effectiveness of metal-coating plastics for information terminals

Metal-coating plastics are being used as shielding materials for electronic and information terminals due to their light weight. In this paper, a finite-difference time-domain (FDTD) algorithm was newly proposed for analyzing the shielding effectiveness of metal-coating plastics in a broad frequency band. The method was based on the derivation of a time-domain representation of the surface resistance of an equivalent resistive film. The validity of the proposed algorithm, for both far-field and near-field shielding, was verified by comparing the calculated results with theoretical ones. Good agreement was found between them when the size of the shielding material is sufficiently large compared to the wavelength.