摘要
由中北大学研制的MEMS仿生矢量水听器具有低频、小尺寸、灵敏度高等性能特点;但是由于受封装结构的影响,该水听器的灵敏度和频率响应还不太理想。为此,研究了聚氨酯透声帽封装对水听器性能的影响。首先,采用ANSYS对封装结构进行仿真,将仿真结果与自由场中液体质点的振动位移进行了对比分析。然后,通过实验对比有无封装两种情况下的水听器性能。最终得出:封装结构的固有机械特性耦合作用于水听器MEMS芯片上,导致水听器频率响应起伏较大,并在透声帽的共振频率处出现峰值;自由场中,透声帽随声波摆动的偏斜量与液体质点位移不相符导致水声衰减引起水听器灵敏度下降。
The MEMS bionic vector hydrophone developed by North University of China has advantages of low frequency, miniaturization, high sensitivity, etc. However, the sensitivity and the frequency response of this hydro- phone is not very good because of the influence by the packaging structure. Therefore, the research that how the sound-transparent cap exerts influences on hydrophone is indispensable. First, the inherent properties of packaging is simulated by ANSYS and a comparative analysis was made with the simulation and the vibration displacement of liquid particle in free field. Then, the performances＇ test of hydrophone with encapsulation and without it were re- spectively carried out in the standing wave tube. Results show that the inherent mechanical properties of the encap- sulation structure act on MEMS chip of hydrophone, leading to that the hydrophone＇ s frequency response curve fluctuates heavily, and the pick value was at the resonant frequency of the cap. Because of the inconformity between the cap＇ s deflection made by the acoustic oscillation with the vibration displacement of liquid particle, the sensitivity of hydrophone has been decreased due to acoustic attenuation.
出处
《科学技术与工程》
北大核心
2014年第4期33-36,42,共5页
Science Technology and Engineering
基金
国家"863"计划(2011AA040404)
国家自然科学基金(61127008/F040703)资助
关键词
矢量水听器
透声帽
封装
ANSYS
vector hydrophone sound-transparent cap encapsulation ANSYS
