水下应用的电容式微机械超声换能器阵列设计

Array design and test of capacitive micromachined ultrasonic transducer used underwater

为提高用于水下成像的电容式微机械超声换能器的指向性,文中用ANSYS力电耦合分析法设计了工作频率为400 k Hz的收发一体传感器的结构参数并完成了实验验证。同时研究了阵列设计方法,分析了电容式微机械超声换能器阵列各参数对指向性的影响,完成了从微小敏感单元到阵列的设计,实现了阵列指向性的优化设计。该阵列为16阵元的线阵,阵元间距为1.925 mm,阵元宽度为1.82 mm。进行了水下指向性测试,实验表明该线阵的-3 dB主瓣宽度为5?,最大旁瓣级为-13.5 dB,对称性好。该设计是实现较远距离的探测,提高成像分辨率的前提。

In order to improve the directivity of capacitive micromachined ultrasonic transducer used inunderwater imaging,the structure parameters of a transceiver integrated sensor are designed using force electriccoupling analysis method in this paper,the working frequency of which is400kHz and experimental verificationis completed.The array design criterion is studied,the influence of various parameters of CMUT array on thedirectivity is analyzed,the design from cell to array is completed,and the optimum design of array directivityis realized.A linear array is designed,which has16elements,element distance is1.925mm,and element widthis1.82mm.Underwater directivity test is conducted,the experiments show that the3dB main lobe widthof the line array is5°,maximum sidelobe level is??13.5dB,and it has good symmetry.The studies lay afoundation for long distance detection and high resolution imaging.