A Novel Mode-Localized Accelerometer Employing a Tunable Annular Coupler
Luhan Zu, Yongcun Hao, Meng Wang, Honglong Chang
Abstract
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 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$13.65 \mu \text{g}/\surd $ </tex-math></inline-formula> Hz noise floor and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$22 \mu \text{g}$ </tex-math></inline-formula> 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.