Stability Analysis and Design Criteria of Paralleled-Device Power Amplifiers Under Large-Signal Regime

This paper describes a method for the stability analysis and stabilization criteria in multi-device paralleled power amplifiers (PA) under large-signal operating conditions. The symmetry of the amplifier is exploited for a simple and effective study of odd- and even-order modes. The overall stability analysis is transformed into a sequence of analyses on single-mode single-transistor large-signal equivalent amplifiers, which are carried out by using a conversion matrix approach. Examples of application of the method are provided on a 9-GHz GaAs pHEMT monolithic-microwave integrated-circuit (MMIC) PA and a 590-MHz power silicon bipolar hybrid microwave integrated-circuit (HMIC) PA.