Design and phase-noise modeling of temperature-compensated high frequency MEMS-CMOS reference oscillators

Phase-noise modeling;Phase-noise;Oscillator;VCO;Micromechanical oscillator;Capacitance cancellation;Negative capacitance;Negative impedance converter;Temperature compensation;Linear CMOS voltage to current converter;Piezoelectric resonator;Capacitive resonator;Tuning enhancement;TIA;Transimpedance amplifier;MEMS;Frequency tuning

Miri Lavasani, Seyed Hossein ; Electrical and Computer Engineering

University:Georgia Institute of Technology

Department:Electrical and Computer Engineering

关键词: Phase-noise modeling;    Phase-noise;    Oscillator;    VCO;    Micromechanical oscillator;    Capacitance cancellation;    Negative capacitance;    Negative impedance converter;    Temperature compensation;    Linear CMOS voltage to current converter;    Piezoelectric resonator;    Capacitive resonator;    Tuning enhancement;    TIA;    Transimpedance amplifier;    MEMS;    Frequency tuning;   

Others  :  https://smartech.gatech.edu/bitstream/1853/41096/1/Mirilavasani_Seyedhossein_201008_phd.pdf

美国|英语

来源: SMARTech Repository

【 摘 要 】

Frequency reference oscillator is a critical component of modern radio transceivers. Currently, most reference oscillators are based on low-frequency quartz crystals that are inherently bulky and incompatible with standard micro-fabrication processes. Moreover, their frequency limitation (<200MHz) requires large up-conversion ratio in multigigahertz frequency synthesizers, which in turn, degrades the phase-noise. Recent advances in MEMS technology have made realization of high-frequency on-chip low phase-noise MEMS oscillators possible.Although significant research has been directed toward replacing quartz crystal oscillators with integrated micromechanical oscillators, their phase-noise performance is not well modeled. In addition, little attention has been paid to developing electronic frequency tuning techniques to compensate for temperature/process variation and improve the absolute frequency accuracy.The objective of this dissertation was to realize high-frequency temperature-compensated high-frequency (>100MHz) micromechanical oscillators and study their phase-noise performance. To this end, low-power low-noise CMOS transimpedance amplifiers (TIA) that employ novel gain and bandwidth enhancement techniques are interfaced with high frequency (>100MHz) micromechanical resonators. The oscillation frequency is varied by a tuning network that uses frequency tuning enhancement techniques to increase the tuning range with minimal effect on the phase-noise performance. Taking advantage of extended frequency tuning range, and on-chip temperature-compensation circuitry is embedded with the sustaining circuitry to electronically temperature-compensate the oscillator. Finally, detailed study of the phase-noise in micromechanical oscillators is performed and analytical phase-noise models are derived.