Electromagnetic shielding effectiveness for isotropic and anisotropic materials

'ABCD' and 'Scattering' matrix analysis techniques for determining shielding effectiveness of isotropic and anisotropic multilayered shields are presented. These techniques are well-suited to computer implementation. A variety of materials fit the models used including advanced composite materials (e.g., fiber-reinforced epoxies where the fibers are 'long' and 'oriented'), conductive filled thermoplastics (randomly oriented, chopped fibers or other conductive particles) and the more common metallic shields. Advanced composite materials are now widely used as structural and surface components in aircraft and spacecraft. Chopped-fiber-filled structural foams are used as enclosures for electronic equipment. Such applications require accurate assessment of electromagnetic shielding effectiveness.