Abstract:Composite materials have been widely employed in modern aerospace, automotive and electronics industries. However, when the composite material is used as external layer of the enclosure, its thickness of a few millimeters, becomes a big challenge for the evaluation of electromagnetic Shielding Effectiveness(SE) based on the Finite-Difference Time-Domain(FDTD) method. Subgridding Boundary Condition(SGBC) method combined with the FDTD method is applied to tackle this issue. The SE of different enclosures has been analyzed in the frequency range of 0.1-1 GHz. The results obtained by using SGBC-FDTD method are compared to those calculated using software based on full wave analysis, and good agreements are observed.