Novel Design Space of Load Modulated Continuous Class-B/J Power Amplifier

A novel design space of load modulated (LM) continuous Class-B/J power amplifiers (PAs) is proposed, and a detailed mathematical analysis is presented. The combination of LM technique and continuous mode is introduced to enhance the wideband performance of LM PAs. An inversely proportional relationship between Z L and C out is derived, which indicates that the nonlinear C out can affect the optimal load impedances at output power backoff (OPBO) and the design parameter β should be appropriately adjusted. The measured results of a PA prototype show that the PAE is 39%-45% under LM when OPBO = 5 dB across 1.6-2.4 GHz. Compared with the same PA with fixed Vvar, the proposed PA with optimum V var at 2 GHz achieves a PAE improvement with 11% when OPBO = 5 dB.