A Highly Linear and Efficient CMOS RF Power Amplifier With a 2-D Circuit Synthesis Technique

Abstract

A 2-D circuit synthesis technique (2DCST) is introduced that simultaneously linearizes the AM–AM and AM–PM distortions of CMOS RF power amplifiers (PAs). A class-AB nMOS RF PA fabricated in a <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">${0.18-}\mu{\hbox {m}}$</tex></formula> CMOS process is reported. With a WCDMA signal, the amplifier achieved 41.6% power-added efficiency (PAE) with <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$-{\hbox{33-dBc}}$</tex> </formula> single-adjacent channel power ratio (ACPR1) and 38.5% PAE with <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$-{\hbox{40-dBc}}$</tex></formula> ACPR1 at output powers of 24.9 and 24.0 dBm, respectively. This state-of-the-art linearity and efficiency performance is comparable to that of GaAs HBT linear RF PAs. The 2DCST is applicable to a broad range of analog circuits and other semiconductor technologies.