Energy Storage
Dimensionless mechanical ratio metrics express the ratio of energy stored to energy dissipated per oscillation cycle in resonant micro-electromechanical structures. Spectrum analyzers determine the resonance quality factor by measuring the ratio of peak resonant frequency to the half-power response bandwidth during swept sine excitation. Sourcing specifications mandate minimum target values to ensure high frequency selectivity and low mechanical thermal noise in micro-gyroscopes.
Dissipation Analysis
Energy loss mechanisms in micro-machined resonators include viscous gas squeeze-film damping, anchor support dissipation, thermoelastic attenuation and internal material friction. Achieving a high resonance quality factor requires minimizing these energy dissipation pathways through structural optimization, balance tuning and high-vacuum enclosure packaging. In precision timing references and vibrating beam sensors, higher values yield sharper phase slopes across resonance, reducing phase noise and improving frequency stability against environmental temperature fluctuations.
Metrology facilities measure this parameter by recording ring-down decay time constants following sudden excitation removal in calibrated vacuum chambers.
Bandwidth Measurement
Drive loop electronics utilize high-Q frequency selectivity to sustain low-power self-oscillation at targeted structural natural frequencies. Sustaining a high resonance quality factor reduces driving voltage requirements, minimizing parasitic electrostatic feedthrough into sensitive capacitive pick-off channels. Calibration procedures adjust drive loop gain settings based on measured Q-factor variations across operational temperature bands.
Pressure Limit
Enclosure pressure increases elevate gas molecule collision rates, causing viscous damping to dominate over structural energy storage. Beyond critical cavity pressure thresholds, the resonance quality factor drops rapidly, broadening the resonant peak and degrading sensor signal-to-noise ratios. Quality control certificates state measured Q-values under final package vacuum seal conditions.
