A 1.0-V 15.6-dBm 39.5%-PAE CMOS Class-E Power Amplifier with On-Chip Transformer for Q Enhancement

A 1-V fully-differential two-stage CMOS class-E power amplifier operating at 2.4 GHz is presented. An on-chip transformer-feedback topology is applied in the pre-amplifier in order to provide a high swing to drive the second stage. Injection-mode-locking topology is employed in the second stage to achieve high output power and high efficiency. Implemented in a 0.18-mum CMOS process, the amplifier delivers an output power of 15.6dBm with 39.5% PAE at a 1-V supply and an output power of 20.3dBm with 43% PAE at a 1.8-V supply, respectively