A unified SPICE compatible model for large and small signal envelope simulation of linear circuits excited by modulated signals

The envelope simulation method, developed earlier for large signal simulation (time domain, TRAN), is extended to include small signal envelope simulation (AC) and DC sweep simulation (steady state for a range of carrier frequencies). The model is derived for AM, FM and PM modulation schemes and is demonstrated on a piezoelectric transformer circuit. The analytical derivations of the model were verified against full circuit simulations that include the high frequency carrier. Excellent agreement was found between the simulation results according to the new unified envelope model and the full simulation.