Electromagnetic Shielding Effectiveness of Coated Textiles

A mathematical model is required for the propagation of electromagnetic (EM) waves through a textile that is coated with a metal layer, and for propagation through a sheet of woven copper wire. Maxwell's equations are solved for a three-layer boundary-value model for EM waves penetrating coated fabric, obtaining the dependence of transmission and reflection coefficients on the thickness of the metal coating. An extension to model the attenuation of EM waves passing through knitted copper wire indicates that approximating the knitting by a sheet of metal with a constant thickness that gives the same mass of metal per unit area does not match experimentally observed attenuations.