Design of high-efficiency multi-octave power amplifier with phase shift parameter

In this letter, a novel load design space is proposed based on the resistance-resistance series of continuous modes (Res.-Res. SCMs) for designing high-efficiency power amplifiers (PAs) with multi-octave. By introducing a phase shift parameter into the voltage waveform expression of Res.-Res. SCMs, the load design space is expanded, enabling greater design flexibility and bandwidth enhancement. To validate the proposed approach, a multi-octave PA was designed and implemented using a GaN HEMT. Measurement results show that the PA achieves a drain efficiency (DE) of 55.3-73.9%, an output power of 38.7-41.2 dBm, and a gain of 9.7-12.2 dB across 0.5-3.9 GHz, corresponding to a relative bandwidth of 154.5%.