Design of GaN HEMT Transistor Based Amplifiers for 5 - 6 GHz WiMAX Applications

2.5 and 5 Watt average power (15 and 30 Watt peak power) GaN HEMT amplifiers for WiMAX signal protocols have been designed and fabricated for use in the 5.5 to 5.8 GHz band. The 2.5 Watt PA produces 11 dB of gain and the 5 Watt PA produces 10 dB of gain with EVMs less than 2.5% at the respective average power with drain efficiencies greater than 26% at average power. A design methodology for optimizing linear performance is described for these two transistors and resultant amplifiers.