摘要
电容式微机械超声换能器(CMUT)声学辐射与振膜的振动紧密关联,因此开展振膜振动与声学辐射的定量关系研究是器件设计的重要依据。先运用薄板振动理论分析了圆形振膜振动的谐振频率与振动模态;再运用瑞利-索末菲衍射公式对CMUT的振动模态进行声学辐射建模;最终得到在基频振动时CMUT圆形振膜的材料、半径、厚度与辐射声场、指向性的关系。与经典的活塞近似理论计算声学辐射相比,采用本文提出的振动模态方法提高了计算CMUT声学辐射的准确性。计算结果表明:在基频振动时CMUT辐射指向性更弱,且具有更低的旁瓣。
The acoustic radiation of capacitive micromachined ultrasonic transducer(CMUT)is closely related to the vibration of vibration diaphragm.Therefore,research on quantitative relationship between diaphragm vibration and acoustic radiation is an important basis for device design.Fitstly,resonant frequency and vibration mode of circular diaphragm vibration are analyzed by using thin plate vibration theory,and then the acoustic radiation modeling of CMUT vibration modeing is established by using Rayleigh Sommerfeld diffraction formula.Finally,the relationship between the material,radius and thickness of CMUT circular diaphragm and the radiated sound field and directivity is obtained.Compared with the classical piston approximation theory to calculate acoustic radiation,the proposed vibration mode method improves the accuracy of calculating CMUT acoustic radiation.The calculation results show that the directivity of CMUT radiation is weaker and has lower side lobe when it vibrates at the fundamental frequency.
作者
高鹏飞
何常德
张彦军
张文栋
张国军
GAO Pengfei;HE Changde;ZHANG Yanjun;ZHANG Wendong;ZHANG Guojun(State Key Laboratory of Dynamic Testing Technology,North University of China,Taiyuan 030051,China)
出处
《传感器与微系统》
CSCD
北大核心
2022年第4期10-13,共4页
Transducer and Microsystem Technologies
基金
国家重大科学仪器研制项目(61927807)
山西省“1331工程”重点学科建设计划资助项目(1331KSC)。
关键词
电容式微机械超声换能器
薄板振动
声场
指向性
capacitive micromachined ultrasonic transducer(CMUT)
thin plate vibration
sound field
directivity
