Wideband, Low-Noise Accelerometer With Open Loop Dynamic Range Of Better Than 135db

This paper reports a high performance capacitive accelerometer with a noise level of 350 ng/root Hz, bandwidth of 4.5kHz, and 135 dB open loop dynamic range at 1Hz bandwidth. The accelerometer was designed in a mode-tuning structural platform. This platform is developed to address the issue between sensitivity and bandwidth for the low-noise capacitive in-plane accelerometers. The platform proposes to substitute the accelerometer's proof mass with a moving frame. Furthermore, the elastic elements and anchor points are located both inside and outside the moving frame. As such, the mode-tuning structural platform contributes in tuning the resonance frequencies and mode shapes of the accelerometer to acquire higher bandwidths. The proposed platform also addresses the issue of sensitivity by increasing the number of sensing elements located inside and outside the moving frame. To the best of the authors' knowledge, no MEMS accelerometer has been able to offer such a combination of high performance metrics, making this platform a viable candidate for developing high performance accelerometers.