Separation of high and low frequency behavior in non-linear circuit simulation, excited with modulated signals

Exciting non-linear circuits with modulated signals will generate crossmodulatlon frequencies. In ordinary simulation techniques this makes time stepping methods a necessity. In the case of EMC testing where the carrier frequency is as high as 2 GHz and the modulating frequency only 1 kHz, the simulation time will be extremely long. This paper presents Time Domain Frequency Separation (TDFS), a method where the high and low frequency behavior is calculated separately to decrease the computation time. In a simulation made with Saber the calculation took approximately fourteen hours, and with TDFS in Matlab two minutes,