CMOS RF Power Amplifier Variability and Reliability Resilient Biasing Design and Analysis

Abstract

This paper presents a novel biasing design that makes the complementary metal-oxide-semiconductor radio frequency power amplifier (PA) resilient to process variability and device reliability. The biasing scheme provides resilience through the threshold voltage adjustment, and at the mean time, it does not degrade the PA performance. Analytical equations are derived for studying the resilient biasing on PA process sensitivity. A class-AB PA with a resilient design is compared with a PA without such a design using a Predictive Technology Model 65-nm technology. The Advanced Design System simulation results show that the resilient biasing design helps improve the robustness of the PA in <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1dB</sub> , <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sat</sub> , and power-added efficiency. Except for postfabrication calibration capability, the adaptive body biasing design reduces the impact of variability and reliability on PA significantly when subjected to threshold voltage shift and electron mobility degradation.