Abstract: In this paper, in order to solve the problem of low efficiency of traditional wideband high-power amplifier, a new type of resistive reactance continuous B/J power amplifier mode is adopted to expand the output load impedance space of transistor with high efficiency. As a result, the drain stage output efficiency of broadband power amplifier is improved. Then, a balanced power amplifier (PA) based on 0.25 μm gate-length GaN HEMT is proposed. The PA combines LC matching network and Chebyshev impedance converter to realize broadband input and output impedance matching of GaN HEMT device, and utilizes a 3 dB Lange coupler to achieve broadband balanced power combination. Under the operating condition of continuous wave (CW), the proposed balanced PA has an output power greater than 100 W, drain efficiency greater than 45%, power gain greater than 9 dB, and anti-load mismatch better than 5:1 in the frequency range of 2 GHz to 6 GHz.