Spectral analysis through electromechanical coupling

A general dynamic model for a momentum-actuated accelerometer is constructed, where both differential and common-mode actuation voltages are considered. The equivalent quasi-static model is applied to design a measurement scheme for low-frequency accelerations. A more general method for real-time spectral analysis of mechanical vibrations is presented, which relies on a feedback loop based on capacitive sensing, on-chip signal conditioning and electrostatic 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 Science S.A. All rights reserved.