High-Q Support Transducer MEMS Resonators Enabled Low-Phase-Noise Oscillators
Journal
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Journal Volume
68
Journal Issue
4
Pages
1387-1398
Date Issued
2021
Author(s)
Abstract
Structural and electrode material engineering methodology to attain quality factor enhancement in a support transducer enabled Wine-glass and Lam? mode resonator has been demonstrated in this work. To boost the quality factor, a series of short mechanical couplers is utilized to link the central resonant structure with the piezoelectric transducer arms. Two different top electrode materials are investigated, and the effect of metal loading on the performance of aluminum nitride (AlN)-on-Si-based resonator is investigated in detail. The new resonator design strategy improves the quality factor of the Wine-glass resonator from 9800 to 16 300 while still being able to maintain a spurious-free spectrum for a 200-MHz span, which is crucial for oscillator applications. An optimized oscillation system is realized using a commercially available low-noise amplifier. Careful positioning of the passive components is utilized to attain an ideal operating point for the resonator in the closed-loop condition. Using this scheme, Wine-glass and Lam? mode resonator-based high-performance oscillators with a low phase noise of -133.6 and -132.7dBc/Hz at 1-kHz offset and -153.7 and -150.4 dBc/Hz at 1-MHz offset, respectively, which satisfy that the Global System for Mobile (GSM) communication requirements are attained when normalized to a 13-MHz carrier frequency. ? 2020 IEEE.
Subjects
Aluminum nitride; Electrodes; Glass; Global system for mobile communications; III-V semiconductors; Low noise amplifiers; Microelectromechanical devices; Oscillators (electronic); Resonators; Transducers; Wine; Aluminum nitride (AlN); Carrier frequency; Electrode material; Global system for mobiles; Low phase-noise oscillators; Oscillation system; Resonant structures; Top-electrode materials; Phase noise
Type
journal article