2-GHz band cryogenically-cooled GaN HEMT amplifier for mobile base station receivers

This paper presents a 2-GHz band gallium nitride (GaN) high electron mobility transistor (HEMT) amplifier cryogenically cooled to 60 K as a part of the cryogenic receiver front-end (CRFE) for mobile base station receivers. The GaN HEMT amplifier attains the output power of 3 W and the maximum power added efficiency of 62% with a 50 V drain bias for class-AB operation. The results reported herein are the first on the performance of a cryogenically cooled GaN HEMT amplifier aiming at use in a 2-GHz band CRFE.