EMI radiation physics using generalized characteristic mode (GCM) analysis with loss for practical structures

Abstract

Characteristic mode analysis has been proposed for lossless case for decades. However, for real electromagnetic interference (EMI) structures, such as printed circuit board (PCB) midplane connector and heat sink, lossy material (such as copper) and terminations (resistive loads) are unavoidable which tradidiotnal CM method cannot handle. In this paper, a generalized CM analysis for lossy material and/or with resistive loads is developed for practical structures. With the proposed method, by applying integral-equation (IE) based method and characteristic mode (CM) analysis, the current is split into radiating and non-radiating ones. The radiated power from each part of the structure can be quantified using the radiating current. Therefore, the radiation hot spot can be identified. This method facilitates the CM method in real applications.