Analysis on the intrinsic design space of DLM continuous class-B/J power amplifier

The analysis on the design space at the intrinsic plane for dynamic load modulated (DLM) continuous Class-B/J power amplifier (PA) is presented in this paper. The proposed intrinsic design space extends the classical design space of the continuous Class-B/J power amplifier which is the special case operated at the saturated power, and it indicates a potential that DLM continuous Class-B/J PA can achieve broadband performance. Based on the proposed intrinsic design space, DLM PA can maintain high efficiency at a large dynamic range of output power. A 15 W GaN HEMT device CGH60015D provided by CREE is used to verify the proposed design space at three frequencies of 1.5 GHz, 2.0 GHz and 2.5 GHz. The measured drain efficiency and output power by load-pull measurements show that the proposed design space can give a distinct guideline for engineers to choose the optimal load impedances at the intrinsic plane for developing DLM PAs.