Computational technique for the periodic steady-state analysis of large nonlinear circuits

A comparison of the computation speed and storage requirements of three algorithms for the determination of the periodic steadystate response of nonlinear circulits, namely the Newton, extrapolation, and gradient methods, shows the latter to be the most attractive if an efficient function minimization routine is available. The gradient algorithm equations have been derived on the basis of a general tableau representation of the network equations which, in contrast to the recently reported state variable formulation, lends itself to straightforward implementation in modern, network, transient analysis programs which use sparse matrix techniques. The algorithm has been implemented with one such program and tested on several circuits using two optimization routines. Satifactory results are obtained with the variable metric routine but convergence is sensitive to scaling and the initial time.