Analytical Formulation for Shielding Effectiveness of a Lossy Enclosure Containing Apertures

The paper deals with an analytical formulation for shielding effectiveness evaluation of a lossy rectangular enclosure containing apertures. On the basis of circuit model theory, an extremely fast technique to include conductor losses into the model is derived. The enclosure is taken into account as a short-circuited waveguide. Lossy conductive walls of the cavity are modeled using a surface impedance boundary condition and electromagnetic field attenuation in waveguide propagation is considered. Our model takes readily accounts higher order resonant modes. Several enclosures with different conductivities and apertures are studied. Results predicted with the model shows very good agreement with those obtained using a full wave method. Our model is more accurate compared to existing ones.