High efficiency wideband continuous class power amplifier design based on reflection coefficient circle impedance area optimization

Abstract

This paper proposes a high-efficiency wideband continuous-class power amplifier (PA) optimizing the fundamental and harmonic impedance areas to achieve wideband and efficient operation. Unlike conventional impedance area constraint methods, reflection coefficient circles are used to characterize the desired fundamental and harmonic impedance areas, thereby increasing the number of feasible solutions in the output matching network (OMN) optimization. Additionally, a multi-objective algorithm is employed to optimize the OMN, enabling the PA to achieve high efficiency over wide frequency band. To validate the feasibility of the proposed method, a continuous-class PA operating in the frequency range of 1.5-2.6 GHz is designed and measured. The results demonstrate that the PA achieves a saturated output power of 40-41.5 dBm with a corresponding gain around 10 dB. Maximum efficiency ranging from 68% to 75% can be achieved within the operating frequency range.