Epitaxially-encapsulated quad mass gyroscope with nonlinearity compensation

P Taheri-Tehrani, M Kline, I Izyumin… - 2016 IEEE 29th …, 2016 - ieeexplore.ieee.org
2016 IEEE 29th International Conference on Micro Electro …, 2016ieeexplore.ieee.org
We present an epitaxially-encapsulated 2× 2 mm 2 quad-mass gyroscope (QMG). Relative
to the earlier QMG which measured 8× 8 mm 2 and required an external vacuum package
and getter [1], this device is 16x smaller in area and is vacuum-sealed at the wafer-level.
Due to the device's small size, high quality factor (Q) and large oscillation amplitude are
required to achieve low noise. However, the device's high Q (85,000) makes it highly
sensitive to mechanical nonlinearity, resulting in amplitude-frequency dependence and …
We present an epitaxially-encapsulated 2×2 mm 2 quad-mass gyroscope (QMG). Relative to the earlier QMG which measured 8×8 mm 2 and required an external vacuum package and getter [1], this device is 16x smaller in area and is vacuum-sealed at the wafer-level. Due to the device's small size, high quality factor (Q) and large oscillation amplitude are required to achieve low noise. However, the device's high Q (85,000) makes it highly sensitive to mechanical nonlinearity, resulting in amplitude-frequency dependence and instability of the oscillator loop at large amplitudes. To overcome these problems, we demonstrate electrostatic compensation of the mechanical nonlinearity, enabling 10x greater amplitude and therefore scale factor (SF). Together with closed-loop amplitude control and quadrature compensation, this enables angle-random walk of 0.42 mdeg/s/VHz, comparable to the best QMG published to date. Closed-loop amplitude control and quadrature null are used to achieve a bias instability of 1.6 deg/hr.
ieeexplore.ieee.org
以上显示的是最相近的搜索结果。 查看全部搜索结果