硅微谐振式加速度计2种谐振结构比较  

Comparison of two resonant structures in silicon oscillating accelerometers

作　　者：董景新[1] 曹宇[1] 万蔡辛[1] 胡淏[1] 

机构地区：[1]清华大学精密测试技术及仪器国家重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2010年第11期1825-1828,共4页Journal of Tsinghua University(Science and Technology)

基　　金：国家"十一五"预研项目(51308050208)

摘　　要：硅微谐振式加速度计多采用双端固定音叉(DETF)作为谐振结构,而传统的单根振梁结构也具有其独特优势。该文通过理论分析、有限元仿真和实验验证,给出了2种谐振结构的比较结果:单根振梁结构的标度因数约为DETF的1.76倍;随着工作环境气压的增大,DETF结构的机械品质因数Q从单根振梁结构的1.95倍(气压为0.01 Pa)减小至1.12倍(气压为86.8 Pa)。此外,由于国内现有微加工工艺限制,加工得到的DETF结构2根振梁的谐振频率存在一定误差,给外围电路的设计造成了一定困难。While the double-ended tuning fork（DETF） has been remarked as a promising resonant structure for silicon oscillating accelerometers,the traditional single-beam structure has its unique advantages.This paper presents detailed comparison between two structures through theoretical analyses,finite element simulation and prototype tests.The results indicate that the scale factor of the single-beam structure exceeds that of DETF with a ratio around 1.76,while the mechanical quality factor of DETF exceeds that of the single-beam structure with a ratio range from 1.95 with an air pressure of 0.01 Pa to 1.12 with an air pressure of 86.8 Pa.The beams of the prototyped DETF can be observed to have undesired difference in the resonant frequency caused by machining errors during manufacturing,which brings difficulty to servo-circuit design.

关 键 词：微机电系统 硅微谐振式加速度计 谐振结构 双端固定音叉 标度因数 机械品质因数 

分 类 号：TH7[机械工程—仪器科学与技术]