A Continuous-Mode Class-F-1 X-band GaN MMIC Power Amplifier with a 29.7 % Fractional Bandwidth

This paper presents a high-performance X-band continuous-mode Class-F-1 MMIC power amplifier (PA) in 0.25-m GaN technology. Design considerations and challenges of continuous-mode Class-F-1 (CCF-1) have been discussed. Broadband matching networks with low losses are designed by accounting for varying optimal impedances at different frequencies and power levels with minimal components. Measured results show the CCF-1 PA achieving Psat of 37.4 dBm, with a peak PAE of 44.3%, and a gain of 21.2 to 24 dB in the f-3dB from 8.3 to 11.2 GHz (29.7%). Performance evaluation using a 5G NR FR1 256-QAM 100-MHz bandwidth modulated signal yields an average Pout of 31.3 dBm, meeting the 3.5% error vector magnitude (EVM) requirement. Compared to the previously published 0.25-m GaN MMICs with harmonic tuning in a similar frequency range, this work achieves the largest fractional bandwidth, and the FoMs are among the best.