Design Approach for Realization of Very High Efficiency Power Amplifiers

This paper presents a systematic methodology for overcoming the practical design problems inherent to real world high efficiency power amplifier (PA) designs. The approach is based on measured RF waveforms and hence guarantees the definite accomplishment of high efficiency modes of operation. The study highlights the important design considerations which must be understood in order to correctly engineer voltage and current waveforms at the device output. The factors limiting performance from reaching ideal efficiency values are clarified and demonstrated on a real device. The impact of device scaling is also explained, showing the increased difficulty in realising high efficiency amplifier modes in large periphery devices.