硅谐振式压力微传感器闭环系统  

Closed-loop system of silicon resonant pressure micro-sensor

作　　者：李海娟[1] 周浩敏[1] 

机构地区：[1]北京航空航天大学仪器科学与光电工程学院,北京100083

出　　处：《北京航空航天大学学报》2005年第3期331-335,共5页Journal of Beijing University of Aeronautics and Astronautics

基　　金：航天科学基金资助项目 (0 3B5 1 0 49)

摘　　要：硅谐振压力微传感器在自激振荡回路中采取电阻热激励、电阻拾振时得到的信号 ,由于有用信号本身的量级小 ,因而含有严重的同频干扰信号 (耦合激励信号 ) ,信噪比SNR (SignalNoiseRatio)仅为 1 0 - 3数量级 .为了提高信噪比 ,滤除同频干扰 ,多级放大之后的处理中将锁相环PLL (Phase-LockedLoop)工作原理和分频技术相结合 ,由锁相环输出作为传感器的激励和鉴相相关信号 ,搭建硅谐振压力微传感器闭环自激振荡回路 .结果表明 :采用锁相分频技术的微传感器闭环系统能可靠运行 。When the silicon resonant pressure micro-sensor works in the self-oscillation close-loop system with thermal-excited and resistor detected, its output has a problem of dreadfully weak signal of micro-sensor. SNR (signal-to-noise ratio) is as low as 10-3, for the system used frequency-equaled signal to excite micro-sensor to get its syntony, as well caused the damaging coupling disturbance. PLL (phase-locked loop) principle and frequency-divided technique were used to design the double closed-loop control circuit of micro-sensor to avoid those. Micro-sensor worked in the outside loop and PLL made the inside loop. The frequency output of micro-sensor had frequency-equaled exciting signal and duple frequency true signal, after multilevel power amplification multiplied duple frequency output of PLL to achieve frequency dividing, adjusting the system state parameters made closed-loop available and phase locking. Results show that the closed-loop system of micro-sensor works effectively based PLL principle and frequency-divided technique and the low SNR gets developed.

关 键 词：同频干扰 锁相环 谐振 信号 分频 信噪比 PLL 压力微传感器 闭环系统 热激励 

分 类 号：V249[航空宇航科学与技术—飞行器设计] TP212[自动化与计算机技术—检测技术与自动化装置]