水下探测微电容超声波换能器线阵设计与封装

Design and Encapsulation of Capacitive Micromachined Ultrasonic Transducer Linear Array for Underwater Detection

提出一种应用于水下探测的低频微电容超声波换能器阵列。在分析微电容超声波换能器阵列复合结构和工作原理的基础上,建立了换能器阵元和一维线阵的指向性表达式,并通过分析结构参数对指向性的影响,确定了阵列几何参数。针对微电容超声波换能器水下应用需求,研究了阵列水下封装方法,通过封装结构设计和封装材料的选取,完成了换能器阵列水密封装。同时,制定了换能器阵列性能测试方案,并搭建了相应的测试、探测系统,经测试换能器线阵-3dB主瓣宽度为5°,最大旁瓣级为-13.5dB,可实现水下1m范围内的目标清晰探测。实验表明,提出的微电容超声波换能器阵列设计和封装方法合理,为改善微电容超声波换能器阵列水下探测性能提供了设计依据。

A low frequency capacitive micromachined ultrasonic transducer(CMUT)array is presented to detect underwater.Based on the analysis of CMUT array structure and work principle,the directivity expressions of CMUT element and the one-dimensional array is established combined with the array composite structure,the geometric parameters are determined in view of the influence on the directivity of CMUT array.According to the application requirement of CMUT underwater detection,the paper studies underwater packaging methods of CMUT array complete the CMUT array water sealing through package structure design and packaging material selection.At the same time,the paper develops a CMUT array performance test scheme and sets up the corresponding test and detection system.The test results show the low-frequency CMUT has better detecting directivity,the-3dB main beam width and maximum sidelobe level for CMUT array are respectively 5°and 13.5 dB,and the CMUT array can realize clear underwater detection within the scope of 1m.The experiment results show the proposed design and encapsulation method is reasonable,and provide the design basis for improving the underwater detection performance of CMUT array.