A Comparison of Iterative Methods for the Solution of Nonlinear WDFs with Non-Lossless Junctions

Circuits containing multiple nonlinear elements are typically solved by means of iterative techniques. Recently, Wave Digital Filters (WDFs) have demonstrated good performance for the simulation of circuits containing a high number of nonlinearities. In particular, the vast majority of the approaches available in the literature consider WDFs characterized by reciprocal lossless connection networks. In this article, we provide, instead, a comparison of iterative methods for the solution of WDFs characterized by non-lossless junctions with involutory scattering matrices, e.g., connection networks absorbing nullors. We run different tests at different amplitudes and frequencies, unveiling and giving insights into the trade-off between convergence speed and simulation time.