Design of X-band 40 W Pulse-Driven GaN HEMT Power Amplifier

In this paper, a design of X-band (9 similar to 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 15x17.8 mm(2) shows an efficiency of above 32%, power gain of 8.7 similar to 6.7 dB and output power of 46.7 similar to 44.7 dBm at 9 similar to 10 GHz with pulse width of 10 mu sec and duty of 10 %.