1.2-V 5.8-GHz 90nm CMOS RF power amplifier parameter enhancement techniques

In this study, two parameter enhancement techniques, Transformer-based power combining and Diode linearization, which can improve the performance of a power amplifier, are implemented on a Class AB PA and then combined to determine their effectiveness. Using a 1.2-V 90nm CMOS process, a test chip containing the power combining network is fabricated and tested. The obtained results show that the power combining technique increases P_OUT by 13dB in exchange of 2X die area increase. The diode linearizer improves 1-dB input compression point by 1.3dB, IM3 up to 5dB and APC first offset frequency WiMAX specification by 10dB. These are all attained in exchange of a 1.1dB insertion loss.