真空封装的硅微陀螺仪

Vacuum packaged silicon micromachined gyroscope

研究了一种硅微陀螺仪,为了提高品质因数,将其封装在15.5 mm×6 mm的真空腔内.采用一种新方式实现了闭环自激驱动,该方式解耦了闭环驱动的相角和增益条件;优化设计了接口线路,消除了大部分耦合电容;推导开环检测时传递函数、静态灵敏度、带宽的表达式,并分析其影响因素.实验结果表明:驱动频率在1 h内相对变化量为0.000 22%;1 h内驱动幅度相对变化量为0.001 5%;标度因数为12 mV/(°.s-1),线性度为0.075 8%,陀螺输出信号噪声低于31.6μV/Hz12.

Described in this paper is a silicon micromachined gyroscope （SMG） which is packed in a vacuum chamber with the dimension of Ф15.5 mm × 6 mm in order to improve the Q-factors. A new closed-loop drive scheme, which decouples the angle and gain of the self-oscillation-driven, is adopted for the SMG. The interface circuit is optimized to remove most impacts of parasitic capacitances. The expression of transfer function, band width and static sensitivity is deduced in open-loop detection. The experiments show that the relative drift of drive frequency and amplitude in 1 h are 0. 000 22% and 0. 001 5% in one hour respectively, the scale factor is 12 mV/（° s^-1 ）, the linearity is 0. 075 8 % and the noise of output signal is below 31.6 μV/Hz^1/2.