A Low-Noise High-Order Mode-Localized MEMS Accelerometer

This paper reports a precision mode-localized accelerometer operating in a higher-order flexural mode. The accelerometer consists of two symmetric resonators coupled by a central rigid coupler to generate an ultra-weak coupling factor. A reduced noise floor is observed when the resonators operate in the higher-order flexural mode compared to the basic lower-order mode. The mode-localized accelerometer working in the fifth-order mode demonstrates an input-referred bias instability of 130 ng and noise floor of 85 ng/root Hz, which are the best results obtained for accelerometers employing the mode localization paradigm to date. These results indicate that the performance of the mode-localized sensors can be improved by operating at a higher working frequency if the coupling factor and quality factor do not drop significantly. [2020-0365]

Automated summary

This paper introduces a precision mode-localized accelerometer operating in a higher-order flexural mode, achieving ultra-weak coupling factor and reduced noise floor compared to lower-order modes. The accelerometer working in the fifth-order mode demonstrates the best results in terms of bias instability and noise floor among accelerometers using the mode localization paradigm. Operating at a higher working frequency can potentially improve the performance of mode-localized sensors if the coupling factor and quality factor remain stable.