Design Methodology of Low Phase Noise mmWave Oscillator with Partial Cancellation of Static Capacitance of High-Q On-chip MEMS Resonator

Abstract

Fully monolithic carrier synthesis at mmWave frequencies (>10 GHz) seek on-chip high quality factor resonators in micro-electromechanical systems (MEMS) technology. However, at mmWave frequencies, MEMS resonator’s usage is severely limited by its high static capacitance (C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> ) and low electromechanical coupling. In this work, we propose a technique of partial cancellation of C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> of mmWave MEMS resonator to utilize it for the development of an extremely low phase noise oscillator. Based on the proposed technique, we also present a methodology for low phase noise fully monolithic mmWave oscillator design. To validate the proposed technique and methodology, design and simulation results of an oscillator with 10.33 GHz on-chip MEMS resonator model in 65 nm CMOS have been also presented in this paper. Simulation results show that the oscillator achieves phase noise and FoM of -137 dBc/Hz and 212.8 dBc/Hz, respectively at 1 MHz offset, while consuming 2.8 mW power from 1 V supply.