Analytical prediction of the effect of conductive planes on EMC filter structures

This paper deals with modeling and simulation of the influence of conductive cover planes on electrical low-pass filter structures. The filter structures are used for electromagnetic compatibility (EMC) purpose within the frequency range of a few MHz up to 4 GHz. It is shown that there is a significant influence of the conductive planes caused by standing waves between the cover plane and the ground plane. To make an analytical modeling approach possible, the filter structures have to be simplified and the wave equation is solved by means of Greens function. Finally, the results are compared to simulation by a commercial field solver and to measurements on simple printed circuit board structures.