Large signal periodic time-domain circuit simulation

A novel time-domain algorithm has been applied in the field of circuit analysis to model large signal effects under periodic excitation. Conventionally, the need to integrate out initial transients over many cycles had effectively made time-domain simulation impractical. The new algorithm, however, neatly avoids this problem, yielding the periodic steady state directly by simulating over just one cycle. A prototype simulator has been written that implements the algorithm within a circuit context, and it has been used in a preliminary study of large signal harmonic effects in both driven and autonomous circuits. In particular, the following circuits are analysed: a single-stage transistor amplifier, a varicap tuner, a full wave rectifier and a Colpitts oscillator. The nonlinear effect of jump resonance is observed in the varicap tuner circuit. An extension of the basic algorithm beyond harmonic analysis into the realms of mixers and other possibly noncommensurate frequency circuits is proposed. Possibilities regarding mixed-mode circuit/device simulation are also discussed