Exploring Feasible Design Space for Multi-Octave Power Amplifier Using Nonlinear Embedding

This brief presents a design space analysis for optimum load trajectory selection in multi-octave continuous class power amplifiers using nonlinear embedding model. The proposed approach solves the major problem associated with the synthesis of a broadband matching network due to the non-foster behavior of load at the device package terminal. The nonlinear embedding model allows the designer direct access at the current generator plane for applying any load apparently creating desired waveforms for any class of operations. These loads are then projected to the package plane using the model for designing the required matching network. For demonstration, a nonlinear embedding model of 25 W GaN HEMT device from Wolfspeed is extracted and utilized to develop multi-octave continuous class F PA operating in 0.5-2.2 GHz band with 60%-73.8% drain efficiency in measurement.