MEMS加速度计信号光电检测与电容检测的噪声分析  

Noise Analysis of Photoelectric and Capacitive Detection of MEMS Accelerometer Signal

作　　者：曾凡林[1,2] 钟少龙[1] 徐静[1] 吴亚明[1] 

机构地区：[1]中国科学院上海微系统信息技术研究所:传感技术国家重点联合实验室,微系统技术国家级重点实验室,上海200050 [2]中国科学院研究生院,北京100039

出　　处：《传感技术学报》2008年第5期785-790,共6页Chinese Journal of Sensors and Actuators

基　　金：中国科学院知识创新工程重要方向性项目;微系统技术国家级重点实验室基金项目资助

摘　　要：在高精度MEMS扭摆式加速度计电容检测和光电检测实现原理的基础上,分析了该加速度计热机械噪声和电学噪声特性。该加速度计结构在品质因数Q=1和Q=85时,热机械噪声分别为2.4μgn/Hz和0.28μgn/Hz。对于电学噪声,电容检测的电学噪声为3.27μgn/Hz,光电检测在只考虑电学噪声时能分辨的最小加速度可达0.05μgn。对比得出对于扭摆式加速度计结构,光电检测具有比电容检测更小的系统总噪声。The thermo-mechanical noise and electrical noise of MEMS torsional pendulum accelerometer are analyzed respectively, in which the sensitive signal is detected by capacitive or photoelectric circuits. The thermo-mechanical noise of the MEMS sensing structure is 2.4 μgn/√Hz, 0. 28 μgn/√Hz when the quality factor Q of the sensing structure equals 1, 85, respectively. The electrical noise is 3. 27 μgn/√Hz for capacitive detection, while the photoelectric detection has a resolution of 0. 05μgn considering the electrical noise only. So the total noise of MEMS accelerometer with photoelectric detection is smaller than the total noise with capacitive detection.

关 键 词：电容检测 光电检测 热机械噪声 电学噪声 

分 类 号：TH827.4[机械工程—仪器科学与技术] TB533[机械工程—精密仪器及机械]