An over 200-W output power GaN HEMT push-pull amplifier with high reliability

We describe a state-of-the-art 250-W output power AlGaN/GaN HEMT push-pull transmitter amplifier operated at a drain bias voltage of 50 V. We also demonstrated stable operation under RF stress testing for 1000 h at a drain bias voltage of 60 V, for the first time. The amplifier, combined with a digital pre-distortion (DPD) system, also achieved an adjacent channel leakage power ratio (ACLR) of less than -50 dBc for 1-carrier W-CDMA signals with a drain supply voltage of 50 V. We show, for the first time, that an AlGaN/GaN HEMTs push-pull amplifier can fulfill the requirements of W-CDMA systems.