Linearity-optimized GaNHEMT Doherty amplifiers using derivative superposition technique for WCDMA applications

Abstract

Gallium nitride (GaN) high-electron mobility transistor (HEMT) Doherty amplifiers with the optimized linearity for wide-build code division multiple access (WCDMA) applications are represented. At a 7-dB back-off output power, the measured single-carrier WCDMA results show two-way and three-way GaN HEMT Doherty amplifiers with an adjacent channel leakage ratio (ACLR) of -43.2 and -48.2 dBc at +/- 2.5 MHz offset frequency with a drain efficiency of 43.1% and 30.9%, respectively. (C) 2008 Wiley Periodicals, Inc.