Transient-based conversion matrix approach for nonlinear stability analysis

A new methodology aimed at assessing the large-signal stability of nonlinear driven circuits in the large-signal regime is presented. The procedure combines the conversion matrix approach with a transient envelope simulation and can be implemented with most commercial nonlinear microwave CAD tools. A method for the analysis of the onset of spurious oscillation in nonlinear circuits operating in large-signal conditions is also given and criteria for the evaluation and modification of the critical loads that give rise to spurious frequencies are provided. This approach has been successfully tested on a medium-power amplifier.