Design of X-band 40 W Pulse-Driven GaN HEMT power amplifier

In this paper, a design of X-band (9∼10 GHz) 40 W Pulse-Driven GaN HEMT power amplifier is presented. The selected active device is a commercially available GaN HEMT chip from TriQuint. The optimum input and output impedances of the GaN HEMT are extracted from load-pull measurement using automated tuner system from Maury Inc. and load-pull simulation using nonlinear model from TriQuint. The combined impedance transformer type matching circuit of the power amplifier is designed using EM co-simulation. The fabricated power amplifier which is 15×17.8 mm2 shows an efficiency of above 32%, power gain of 8.7∼6.7 dB and output power of 46.7∼44.7 dBm at 9∼10 GHz with pulse width of 10 μsec and duty of 10 %.