Unified approach for large signal stability analysis of 4Watt UHF RF power amplifier

This paper highlights large signal stability analysis on predicting RF power amplifier (PA) circuit instabilities by calculating system´s poles and zeroes from closed loop transfer function of the circuit linearized around its steady state through a small current perturbation excitation at the node the circuit. By using this technique, the nature of amplifier oscillations can be determined, which assists in selecting a suitable strategy for circuit stabilization. The proposed methodology has been successfully applied to analyze and eliminate low frequency oscillations in the design of 4W UHF RF power amplifier.