SPLIT DRIVER STAGES FOR A SWITCHING MODE POWER AMPLIFIER WITH MULTIPAIRS OF POWER STAGES

Abstract

In this study, we analyze the effects of a power splitter on the output power and the power consumption of a CMOS power amplifier using a distributed active transformer as an output balun. On the basis of the analyzed results, we propose a split driver stage structure to mitigate the undesired effects of the conventional power splitter. In the proposed structure, the power splitter is located between the first and second driver stages to isolate the input node of the power stage from the parasitic components of the power splitter. To verify the feasibility of the proposed structure, we designed conventional and proposed 1.9-GHz CMOS power amplifiers using 0.11-mm RF CMOS technology. The measured efficiency and output power of the proposed amplifier are improved compared to those of the conventional amplifier. From the measured results, we successfully verify the feasibility of the proposed split driver stage structure. (C) 2014 Wiley Periodicals, Inc.