面向CMUT阵元的阻抗匹配设计与声场特性测试  

Impedance matching design and sound field characteristic test for CMUT array element

作　　者：李一凡 张赛 何常德 王子渊 高鹏飞 张国军 LI Yifan;ZHANG Sai;HE Changde;WANG Ziyuan;GAO Pengfei;ZHANG Guojun(State Key Laboratory of Dynamic Testing Technology,School of Instrument and Electronics,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学仪器与电子学院动态测试省部共建实验室,山西太原030051

出　　处：《传感器与微系统》2022年第4期89-92,共4页Transducer and Microsystem Technologies

基　　金：国家重大科研仪器研制项目(61927807);国家重点研发计划资助项目(2018YFF01010500)。

摘　　要：为解决电容式微机械超声换能器(CMUT)声发射能力弱、输出声压低的问题,根据CMUT工作原理与阻抗匹配理论设计了匹配电路。在此基础上,测试阻抗匹配前后CMUT的轴向声场与辐射声场指向性。测试结果表明:在相同测试距离或偏转角度时,阻抗匹配后的CMUT输出声压明显提升,且不会影响CMUT的声场特性。通过实验验证与对比分析,该阻抗匹配电路有效改变CMUT的阻抗特性,提升声发射能力,为CMUT的实际应用提供解决方案。In order to solve the problems of weak acoustic emission and low output acoustic pressure of capacitive micromachined ultrasonic transducer(CMUT),the matching circuit is designed according to the working principle of CMUT and the impedance matching theory.On this basis,the directivity of axial and radiated sound fields of CMUT before and after impedance matching is tested.The test results show that at the same test distance or deflection angle,the output sound pressure of CMUT after impedance matching is significantly increased,and the sound field characteristics of CMUT are not affected.Through experimental verification and comparative analysis,the impedance matching circuit effectively changes the impedance characteristics of CMUT,improves the acoustic emission ability,and provides solutions for the practical application of CMUT.

关 键 词：电容式微机械超声换能器 阻抗匹配 SMITH圆图 声场特性 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置] TB552[自动化与计算机技术—控制科学与工程]