A wideband linear CMOS power amplifier design for 2.3-GHz and 2.6-GHz m-WiMAX system

In this work, a fully-integrated linear CMOS power amplifier (PA) is implemented in a 0.18-μm 1P6M RF CMOS process for 2.3-GHz and 2.6-GHz m-WiMAX system application. A wideband twisted figure-8-shaped transformer is utilized as both the power combining and matching, which is operated across 1 GHz bandwidth. The PA operates at Class AB mode and can deliver 29.1 dBm with a 26.5% PAE at 1-dB compression point and offer 22 dB gain. EVM is lower than 5% at 19 dBm average power under the 16 QAM m-WiMAX modulation signal test. Digital feedback pre-distortion (DFDPD) technique is employed to improve spectrum linearity by 7 dB at 19 dBm average power level.