Design Challenges In Continuous Mode Power Amplifiers

This paper analyzes the appropriate design space for continuous mode power amplifiers that results into foster loads realizable with passive matching networks. An insight is presented to engineer the second harmonic loads to provide clockwise trajectory on Smith chart. This enables designers to choose the solutions which are feasible in terms of designing matching network. The scheme presented is validated with two waveform engineering based design examples using Continuous Class B/J and Continuous Class F modes of operation. A 15 W GaN HEMT transistors from Wolfspeed are used to design these power amplifiers to obtain high efficiency over a wide bandwidth.