Analysis and Design of Fully Integrated High-Power Parallel-Circuit Class-E CMOS Power Amplifiers

A design methodology for watt-level, fully integrated CMOS power amplifiers (PAs) is presented. It is based on the analysis of the operation and power loss mechanism of class-E PAs, which includes the effects of a finite dc-feed inductance and an impedance matching transformer. Using the proposed approach, a class-E PA with a 2 $\times$ 1:2 step-up on-chip transformer was implemented in a 0.18- $\mu{\hbox {m}}$ CMOS technology. With a 3.3 V supply, the fully integrated PA achieves an output power of 2 W and a power-added efficiency of 31% at 1.8 GHz.