Analytical model of a shielding enclosure populated with arbitrary shaped dielectric obstacles

Abstract

This paper proposes a new analytical model for an approximate evaluation of the shielding effectiveness (SE) for an enclosure populated with arbitrary shaped dielectric obstacles. The model is based on the enclosure equivalent circuit method proposed by Robinson et al. Dielectric obstacles are taken into account in the calculation of the characteristic impedance and the propagation constant for each regular part situated along the enclosure length. To do this, the model uses the effective value of relative permittivity, which is determined in the cross section of each regular part from a simple percentage ratio. Using the proposed model and the finite element method, the SE calculations were performed for three typical enclosures populated with different dielectric obstacles. The obtained results are in good agreement, and the average value of the absolute error does not exceed 4.4 dB.