High linearity and high power performance with barrier layer of sandwich structure and Al<sub>0.05</sub>GaN back barrier for X-band application
Bin Hou, Ling Yang, Minhan Mi, Meng Zhang, Chupeng Yi, Mei Wu, Qing Zhu, Yang Lu, Jiejie Zhu, Xiaowei Zhou, Ling Lv, Xiaohua Ma, Yue Hao
Abstract
Abstract The high power and linearity performance of GaN-based HEMT for X-band application was achieved using the barrier layer of sandwich structure and Al 0.05 GaN back barrier. The AlGaN-sandwich-barrier can modulate polarization-graded field for more flat transconductance profile under the high drain bias. Only about 7.5% current collapse (CC) occurs for drain quiescent bias of 40 V. Due to the Al 0.05 GaN back barrier, the three-terminal off-state breakdown voltage (BV DS ) of 260 V and a very small drain-induced barrier lowering (DIBL) of 2.7 mV V −1 is achieved. The AlGaN sandwich barrier combined with Al 0.05 GaN back barrier device exhibits a high current-gain cutoff frequency f T of 42 GHz@ V DS = 10 V, and a high power-gain cutoff frequency f MAX of 130 GHz@ V DS = 60 V. Load-pull measurement at 10 GHz revealed a saturated power density of 7.3 W mm −1 was achieved with an associated PAE of 29.2% and Gain of 10.6 dB. Two-tone measurement at 10 GHz showed an OIP3 of 38 dBm and a corresponding linearity figure-of-merit OIP3/ P DC of 4.5 dB. These results demonstrate the great potential of AlGaN-sandwich -barrier/GaN/Al 0.05 GaN HEMTs as a very promising alternative to high power and high linearity X-band power amplifier.