High Power Wideband AlGaN/GaN HEMT Feedback Amplifier Module with Drain and Feedback Loop Inductances Y. Chung, S. Cai, W. Lee, Y. Lin, C. P. Wen, Fellow, IEEE, K. L. Wang, Fellow, IEEE, and T. Itoh, Fellow, IEEE Department of Electrical Engineering, University of California, Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90095, USA E-mail: ykchung@ee.ucla.edu Abstract A high power wideband feedback amplifier module using AlGaN/GaN high electron mobility transistor (HEMT) has been developed that covers the frequency range of DC to 5GHz with small signal gain of 9 dB. Shunt feedback topology is introduced by adding inductances to increase the bandwidth. At midband frequency, power added efficiency (PAE) of 20 % and saturation power level of 29.5 dBm were obtained at a drain voltage of 12 V (V ds ) and a gate voltage of -3 V (V gs ). I. Introduction High power amplifiers with broad bandwidth are key components in phased array radars and communications systems. GaN-based HEMT’s for high power applications at microwave frequencies are now possible. This is due to the high breakdown field, high carrier density, and high electron