Applicability of the thin sheet approximation to the analysis of EM emission from coated PCBs

This paper discusses the application of the so-called thin sheet approximation (TSA) for dielectric coatings to the calculation of the 3D coupling of printed circuit boards (PCBs) using the method of moments (MoM). By extending the TSA to open structures, the volume currents in the dielectric layer can be described by surface currents on the PEC conductor and the problem can be reduced to single current layers. As a consequence, the number of unknowns is reduced drastically. In order to verify the TSA approach and its accuracy and to investigate the influence of the layer and conductor thickness of coated PCBs, comparisons to results obtained by the classical MoM computation and a finite element (FEM) solver are given.