Spectral analysis through electromechanical coupling

A general dynamic model for a momentum-actuated accelerometer is constructe d, where both differential and common-mode actuation voltages are considere d. The equivalent quasi-static model is applied to design a measurement sch eme for low-frequency accelerations. A more general method for real-time sp ectral analysis of mechanical vibrations is presented, which relies on a fe edback loop based on capacitive sensing, on-chip signal conditioning and el ectrostatic actuation. Both common- and differential-mode voltages are used to tune the accelerometer spectral characteristic, in order to extract the spectral component set by the electrostatic actuation. (C) 2000 Elsevier S cience S.A. All rights reserved.