Design-oriented non-linear analysis of class-AB power amplifiers

An efficient and reliable nonlinear analysis method is proposed for the analysis and design of high-efficiency power amplifiers operating in any class. On the basis of a simplified device model, the method can be used for the optimization of efficiency, output power, and drive level of a power stage. A procedure is given for the optimum choice of the operating class, and for the determination of bias point, load, and drive level. The feasibility of the proposed method is demonstrated by comparing the results with the results of a more elaborate nonlinear CAD (computer-aided design) analysis program and with experimental data. The computation of the design tables for a selected transistor is quite fast (approximately one minute on a PC), allowing an easy optimization of the power stage.<>