A Novel Mode-Localized Accelerometer Employing a Tunable Annular Coupler

The tunable coupling structure is proved to be an effective way to improve the adjustability of sensitivity of mode-localized sensors. However, the non-linearity introduced by the electrical coupling structure brings difficulties to its practical application. In this paper, a mechanical sensitivity adjustment method is proposed with lower output non-linearity of amplitude ratio and larger measurement range of acceleration. The proposed accelerometer is tested under closed-loop circuit to obtain 37% sensitivity adjustment range with 0.42% output non-linearity. The experimental results demonstrate 1.45/g initial sensitivity over 40g linear measurement range. The accelerometer also demonstrates $13.65 \mu \text{g}/\surd $ Hz noise floor and $22 \mu \text{g}$ bias-instability. The linear dynamic range is calculated to be 140.2 dB, which provides a very promising solution for acceleration measurement in high-end industrial applications.