2026-02-09 Latest Published
By Lang Ran
Bin Wang
Yongxin Wang
Shihao Chen
Progress In Electromagnetics Research C, Vol. 166, 1-8, 2026
Abstract
A design approach using a harmonic-tuned network (HTN) and terminated coupled-line structures (TCLSs) for high-efficiency filtering power amplifiers (FPA) is proposed in this paper, effectively addressing the efficiency degradation caused by the integration of filtering structures in conventional FPA designs. The proposed approach enables compact circuitry while providing bandpass filtering characteristics. Bandpass filtering is realized through the cascaded TCLSs, while the incorporation of open-circuit and short-circuit branches introduces additional transmission zeros and poles, significantly improving frequency selectivity. In addition, HTN enables precise control of the harmonic impedance, effectively improving the efficiency of the power amplifier (PA). Based on this approach, an FPA operating in the 2.3-2.6 GHz band is designed and implemented. Experimental results show that the FPA achieves a output power (Pout) of 40.8-41.3 dBm, a drain efficiency (DE) of 67.2-72.2%, a gain of 12.8-13.3 dB, and stopband suppression greater than 39 dB on both sides of the passband. These results verify the effectiveness of the proposed design in enhancing PA efficiency and enabling circuit miniaturization, while also providing a feasible design approach for FPA development.
