A 6W Uneven Doherty Power Amplifier in GaN Technology

In this paper the design of a 6 W uneven GaN Doherty power amplifier is presented. The Doherty PA is designed to achieve high efficiency for modulated signals with high peak to average power ratio used in modern wireless communication systems. The Doherty amplifier has been designed using two equal sized GaN devices for the Main Class AB and Peaking Class C amplifiers. An uneven power divider is used at the input to deliver more input power to the Peaking amplifier than the Main amplifier. The measured maximum output power of the realised uneven Doherty is 38 dBm with 60% of peak power added efficiency (76% of drain efficiency). The power added (drain) efficiency is higher than 52% (62%) up to 6 dB of back off, or 42% (45%) up to 10 dB of back off.