Design of Multioctave Bandwidth Power Amplifier Based on Resistive Second-Harmonic Impedance Continuous Class-F

In this letter, a generic method is presented for multioctave power amplifier (PA) based on extended version of the continuous class-F. The theory allows resistive second-harmonic impedance and sacrifices part of efficiency to get a bandwidth over one octave. A high-voltage GaN HEMT is adopted to achieve high output power and drain efficiency. Finally, a 0.2-2.5 GHz miniature multioctave PA is designed and fabricated. Experimental results show the drain efficiency of 55.5%-70.3% and the output power of 43.7-46.9 dBm across 0.2-2.5 GHz (170%). The compact size of the proposed PA can also be observed with only 2.6 cm × 5.5 cm, which is greatly reduced compared with other PAs with similar performances.