This letter presents an integrated 5G NR n79–band power amplifier with high power and efficiency that was fabricated using WIN Semiconductors’ 0.25-µm GaN/SiC technology. The stability and linearity issues of the PA is thoroughly considered. High efficiency and broadband operation were achieved using a continuous Class-F mode output matching network. This two-stage PA had a power gain, 3-dB power bandwidth, saturation power, and peak power-added efficiency of 20.4 dB, 3.6–5.4 GHz, 39.1 dBm, and 50.9%, respectively. Its average output power was 33.3 dBm under an error vector magnitude requirement of 3.5% for a 5G NR FR1 256-QAM 100-MHz-bandwidth modulated signal with a frequency of 3.7–5.0 GHz.