An over 100 W n-GaN/n-AlGaN/GaN MIS-HEMT power amplifier for wireless base station applications

Novel n-GaN/n-AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) with Si₃N₄ film were fabricated on a semi-insulating (S.I.) SiC substrate. An n-GaN/n-AlGaN/GaN MIS-HEMT with a breakdown voltage of 400 V was obtained by using SiN/n-GaN cap structure. The single-chip GaN MIS-HEMT amplifier operated at 60 V achieves a high output power of 110 W with a linear gain of 13 dB at 2.14 GHz. This is the first report of an AlGaN/GaN MIS-HEMT with an over 100 W output power. The MIS-HEMT amplifier, combined with a digital pre-distortion (DPD) system, also demonstrates an adjacent channel leakage power ratio (ACLR) of less than -50 dBc for 4-carrier W-CDMA signals