Radiated emission prediction of a SMPS based on time domain EMF-circuit co-simulation

It´s well known that a switched-mode power supply is easily to produce electromagnetic radiation emission and often fails in EMC test for its RFI exceeding limits between 30MHz–100MHz. The accurate radiation emission prediction technology is very helpful for a SMPS designer to find the potential problems at earlier stage and remove them in advance. This paper proposes a novel time domain simulation method, electromagnetic field-circuit collaborative strategy (FCS), to predict the far-field radiation emission of a Buck converter. The feasibility and deviation of this method are analyzed firstly. Then a buck converter is modeled and simulated to predict its EMI source and far-field radiation emissions. The effectiveness of this method is verified by comparing the prediction results and the experiment results.