Modeling common-mode radiation of 3D structures

Common-mode radiation, which is often the predominant contributor to the overall radiation from circuit boards and electronic hardware, has in the past been difficult to calculate. Since the return paths for common-mode currents are not obvious, all parasitic circuit elements must be properly taken into account. The authors calculate the radiation, which includes both differential and common-mode components, from arbitrarily shaped 3-D conductor-dielectric composite structures using a full-wave approach. Excellent agreement between measured and calculated results is demonstrated. Further, a great deal of insight into the mechanism for generation of common-mode current, and hence radiation, is obtained