一种提高薄膜体声波谐振器质量分辨率的主动控制方法  

An Active Control Scheme for Improving Mass Resolution of Film Bulk Acoustic Resonators

作　　者：贺学锋[1] 刘兴[1] 印显方[2] 温志渝[2] 陈可万[1] 

机构地区：[1]重庆大学光电技术及系统教育部重点实验室,重庆400044 [2]重庆大学微系统研究中心,重庆400044

出　　处：《应用数学和力学》2011年第6期702-709,共8页Applied Mathematics and Mechanics

基　　金：国家自然科学基金资助项目(61076106);国家高技术研究计划(863计划)资助项目(2008AA04Z310);高等学校科技创新工程重大项目培育资金资助项目(708072)

摘　　要：低浓度小分子检测对基于薄膜体声波谐振器的传感器的分辨率提出了较高要求,针对以上需求,提出一种提高薄膜体声波传感器分辨率的主动控制方法,即在谐振器的驱动电压上叠加一个反馈电压,该反馈电压是对通过谐振器的电流施加一个常数增益和一个常数相位差得到.反馈电压产生的声能部分地补偿了材料阻尼和声音散射引起的声能损失,进而提高了薄膜体声波传感器的品质因子和质量分辨率.忽略电极影响,基于连续介质理论得到了具有主动控制功能的薄膜体声波传感器阻抗的显式表达式.数值仿真结果表明,薄膜体声波传感器的阻抗强烈依赖于反馈电压相对于电流的增益和相位差,当采用适当的增益和相位差时,传感器的质量分辨率可以大幅提高.以上主动控制方法对提高石英晶体微天平的分辨率同样有效.High mass resolution of sensors based on nlm bulk acoustic resonators （PBARs） was required for detection of small molecules with low concentration. An active control scheme was herein presented for improving the mass resolution of FBAR sensors by adding a feedback voltage, which was obtained by giving a constant gain and a constant phase shift to the current on the electrodes of the FBAR sensors, onto the driving voltage between two electrodes of the FBAR sensors. The acoustic energy produced by the feedback voltage partly compensates the acoustic energy loss from the material damping and the acoustic scattering, which as a consequence improves the quality factor and the mass resolution of FBAR sensors. The explicit expression relating the impedance to the frequency for an FBAR sensor with the active control was derived based on continuum theory by neglecting the influence of the electrodes. Numerical simulations show that the impedance of the FBAR sensor strongly depends on the gain and phase shift of the feedback voltage and the mass resolution of the FBAR sensor can be greatly improved when appropriate gain and phase shift of the feedback voltage are used. Above active control scheme is also an effective solution to improve the resolution of the quartz crystal mi- crobalance （QCM）.

关 键 词：薄膜体声波谐振器 传感器 主动控制 阻抗 分辨率 

分 类 号：O429[理学—声学]