Evaluation of the effects of an external incident electromagnetic wave on metallic enclosures with rectangular apertures

An analytical model is presented, which is useful to evaluate the shielding effectiveness of a rectangular metallic enclosure with a rectangular aperture. The aperture is modeled as a coplanar transmission line, and the enclosure is modeled as a length of a rectangular waveguide ended by a short. The effects of the incident electromagnetic wave are taken into account by using suitable forcing terms in the equations related to the aperture model. The method provides an approximated solution in closed form, and is useful to achieve a fast evaluation of the shielding effectiveness, which can be computed as a function of the enclosure dimensions, the aperture dimensions, and the characteristics of the incident electromagnetic wave. Numerical simulation results are in good agreement with the results given by other theoretical models. Results also compare well with measurement data. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 28: 289–293, 2001.