Simulating electromagnetic radiation of printed circuit boards

A realistic approach is introduced for the computation of the electromagnetic radiation interference (EMI) from printed circuit boards. The approach is suitable for large problems and real circuit boards can be investigated. Each trace and its source and loads are represented as electrical circuits and a conventional time-domain circuit simulation is used to find the currents. The field is then calculated by applying the free-space Green´s function to all currents including the polarization currents. This is, to the authors´ knowledge, the first CAD tool which can predict EMI from basic principles.<>