Title | MEMS-based mechanical spectrum analyzer |
Publication Type | Journal Article |
Year of Publication | 2005 |
Authors | Rocha, L. A., E. Cretu, and R. F. Wolffenbuttel |
Journal | Instrumentation and Measurement, IEEE Transactions on |
Volume | 54 |
Pagination | 1260 - 1265 |
Date Published | jun. |
ISSN | 0018-9456 |
Keywords | AC-operated capacitive accelerometer, accelerometers, direct mechanical spectrum analysis, electronic modulation, electrostatic actuators, electrostatic force feedback, electrostatic momentum feedback, electrostatic time varying actuation, fast Fourier transform, fast Fourier transforms, force feedback, inverted pendulum accelerometer structure, mechanical domain, mechanical spectrum analyzer, mechanical vibration, MEMS, micromachining, micromachining techniques, micromechanical devices, pendulums, Si, spectral analysers, spring constant, time series, vibration analyzer, vibrations |
Abstract | An ac-operated capacitive accelerometer with electrostatic force feedback is employed for direct mechanical spectrum analysis. Force feedback acts as a means for electronic modulation of the spring constant of the suspension and thus for enhancing the sensitivity. Therefore, a suitable electrostatic time-varying actuation can be used to make the accelerometer selectively sensitive to a coherent frequency component of a mechanical vibration. By sweeping the frequency of the drive voltage over a selected range, the mechanical (vibration) spectrum is analyzed in the mechanical domain. An inverted pendulum type of accelerometer structure has been fabricated in silicon using micromachining techniques and operated using electrostatic momentum feedback. The spectral performance is comparable to fast Fourier transform based systems for spectral analysis on a time series supplied by a conventional accelerometer, while the overall system features a reduced complexity and reduced power consumption. |
URL | http://dx.doi.org/10.1109/TIM.2005.847168 |
DOI | 10.1109/TIM.2005.847168 |