Large-signal characterization and modeling approach suitable for the design of actively load-modulated amplifiers

Abstract

An active load pull based large signal modeling approach suitable for designing and optimizing load modulated amplifiers, such as Doherty or LINC based amplifiers, is proposed. The dynamic loads seen by the amplifier's transistor was optimized using a large signal load pull based behavior model built into a CAD software. The simulation versus measurement results demonstrated the strong ability of the constructed model to predict the nonlinear behavior of actively loaded amplifiers. The developed approach was used to optimize the design of 16 watts peak-envelope power Doherty amplifier in terms of power added efficiency, AM/AM and AM/PM distortions.