Fully-integrated WLAN CMOS PA with reconfigurable transformer

Abstract

A modified series combining transformer incorporating an autotransformer for the dual-mode operation to improve efficiency performance in the low-output power region is presented. The dual-mode CMOS power amplifier (PA) with the proposed reconfigurable transformer is fabricated using 40-nm CMOS technology. Compared with other dual-mode WLAN CMOS PAs, the proposed PA achieves high-efficiency performance in both high-power and low-power modes; in dual-mode operation, the PA has average output power levels of 19.2 and 15.2 dBm with power added efficiencies of 17.3 and 14.4%, respectively, while satisfying the error vector magnitude requirements of WLAN 802.11g signals.