A wideband Gallium Nitride (GaN) HEMT power amplifier (PA) achieving 7.6W output power over 1.1 GHz bandwidth at fo=2.75 GHz is presented. A systematic design and synthesis of wideband low-pass matching networks realizing optimal fundamental impedance is applied. These techniques have produced amplifiers with increased output power, efficiency and very large fractional bandwidth. Additionally, the PA can achieve a maximum 61% power added efficiency. This work seeks to maximize the usable bandwidth of the GaN HEMT PA to the maximum possible operating frequency.