Time-Domain Simulation of Nonlinear Circuits Through Implicit Runge-Kutta Methods

This paper presents a novel approach to the accurate time-domain simulation of nonlinear circuits that employs a class of high-order implicit Runge–Kutta (RK) formulas. The RK methods that are here considered are selected among the wide family of known RK methods as being particularly suited to the task of analog simulation. The properties of stability and accuracy of these RK methods are briefly reviewed while the implementation in the flow of an analog simulator is described in detail. When compared to standard multistep methods, the considered RK techniques reveal to be much more reliable and thus particularly suited to the analysis of those circuits, such as circuits for RF applications or sharply nonlinear switched circuits, that are critical for conventional integration methods.