A loop-breaking method for simulation of feedback circuits using a VCVS-terminated subnetwork model

Abstract

A model for a multi-terminal subnetwork is applied in a loop-breaking method for open and closed-loop analysis of feedback circuits. The model contains two physically disconnected subnetworks having specific terminals connected to grounded voltage-controlled voltage sources (VCVS). Gain pa-rameters of the VCVSs control signal transfer through the model allowing a feedback loop to be opened or closed in a switch-like manner. The method is applied in circuit analysis and simulation where closed-loop dc bias conditions are imposed on the open-loop circuit. Small-signal analysis of the equivalent circuit produces Bode's return-ratio and return difference corresponding to the modeled component.