考虑梳齿动态特性的微加速度计敏感结构等效电学模型  

An improved equivalent electrical model for the sensing element of an accelerometer with comb finger dynamics

作　　者：刘云涛[1,2] 赵磊[3] 王颖[1] 邵雷[1] 

机构地区：[1]哈尔滨工程大学信息与通信工程学院,黑龙江哈尔滨150001 [2]中国科学院微电子研究所,北京100029 [3]中国航天科工集团第二研究院,北京100854

出　　处：《哈尔滨工程大学学报》2012年第8期1046-1051,共6页Journal of Harbin Engineering University

基　　金：中央高校基本科研业务费专项基金资助项目(HEUCF110801)

摘　　要：为确保ΣΔ(sigma-delta)微加速度计系统仿真的正确性,提出一种改进的敏感结构等效电学模型.在分析传统敏感结构等效电学模型局限性的基础上,研究了结构梳齿在外力作用下发生弯曲对闭环系统的影响和使ΣΔ闭环反馈失效的机理,分析了梳齿弯曲对质量块所受静电合力的影响,结合传统电学模型,建立了包含梳齿弯曲因素的改进的等效电学模型.在微加速度计系统仿真中,利用敏感结构的传统模型并不能反映出调制器失效特性,输出显示调制器仍然正常工作,而利用所建立的敏感结构电学模型能够准确的表现出ΣΔ反馈失效现象,为电路仿真的准确性提供了保障.An improved equivalent electrical model for the sensing element of an accelerometer was presented to guarantee the validity of sigma-delta（ΣΔ） micromachined accelerometer simulation.The reason for the bend of comb finger under exterior force causing the ΣΔ closed-loop feedback to be disabled was studied based on the analysis of the limitation of a traditional equivalent model.The influence of the bend of the comb finger on the electrostatic force applied to a proof-mass was analyzed.Along with the traditional model,an improved equivalent electrical model which combines the dynamics of both the proof-mass and the sensing fingers for structures was established.The simulation results show that in accelerometer system simulation,utilizing the traditional model cannot reflect the failure characteristics of the modulator,and the output shows that the modulator works properly.However,using the improved model established in this work would capture the failure of the ΣΔ closed-loop feedback,providing a guarantee for the validity of circuit simulation.

关 键 词：等效电学模型 ΣΔ闭环 微机械加速度计 感应梳齿 

分 类 号：TP824[自动化与计算机技术—检测技术与自动化装置]