Computation of shielding effectiveness of concentric spherical shields with plane wave illumination

As a basic problem for the multilayer shield, the model of the concentric spherical shields being illuminated by a plane wave is investigated and formulated in a computationally suitable form. The incident plane wave and all the fields involved are expressed in terms of spherical vector wave functions, and each spherical shell is expressed by a 2×2 matrix which relates the inner field coefficients to the outer field coefficients. To evaluate the shielding effectiveness of the cavity as a whole. The RMS-based SE (shielding effectiveness) is proposed and its analytical form is derived. Several numerical examples concerning the cavity resonance suppression are shown