硅微谐振加速度计交流检测信号解耦技术

硅微谐振加速度计以高精度的频率信号输出及潜在的敏感结构与处理电路实现一次集成的优势,成为硅微传感器研制的热点之一。针对交流检测信号耦合效应对硅微谐振加速度计性能的重要影响,在分析硅微谐振加速度计工作机理的基础上,从结构和电路两方面研究了交流检测信号耦合效应的来源,分析了耦合效应对检测电路和闭环控制精度的影响。采用双质量块结构方案和电路优化设计所研制的硅微谐振加速度计,基频为15 kHz,标度因数为36 Hz/g,量程为±30 g。试验证明耦合效应对仪表性能的影响降低到0.3 mg以内。

AC detection signal decoupling for silicon resonant accelerometer

The silicon resonant accelerometer(SRA) is one of the study focuses in silicon sensors,which takes quasi-digital signal as output and integrates the structure and circuit on a chip.Aiming at the significant influence of AC signal detection on the performance of SRA,the source and control of the couple effect was studied by analyzing the working principle of SRA.The theory and settlement of the effects of couple signal on circuit detection and control of closed-loop was introduced,and the design method of structure and circuit were optimized.Based on the simulation analysis,the natural frequency and scale factor of the designed SRA are 15 kHz and 36 Hz/g respectively,and the measuring range is ±30g.The experimental results demonstrate the couple effect is decreased to within 0.3 mg.