电容式微机械超声换能器的水下收发性能

Underwater Transceiver Performance of Capacitive Micromachined Ultrasonic Transducer

为满足水下超声探测的应用需求,设计了一种采用硅基集成电路制造工艺制备的电容式微机械超声换能器(CMUT)。首先介绍了CMUT的工作原理及其结构参数,然后完成了CMUT的水密封装,最后对封装后CMUT的电容-电压(C-V)特性、发送电压响应级、接收灵敏度与回波信号进行测试。测试结果表明,封装后的CMUT具有良好的C-V特性,电容变化量最大可达313.7 pF,其发送电压响应级最大值为163.83 dB@2 MHz,接收灵敏度最大值为-228.27 dB@1 MHz,因此其在水下环境具备良好的发射超声波与接收超声波的能力。该研究结果为高密度CMUT阵列的设计和封装及水下超声探测提供了理论和应用依据。

A capacitive micromachined ultrasonic transducer(CMUT)fabricated by the siliconbased integrated circuit manufacturing process was designed to meet the application requirements of underwater ultrasonic detection.Firstly,the working principle and structural parameters of the CMUT were introduced,and then the watertight package of the CMUT was completed.Finally,the capacitance-voltage(C-V)characteristics,transmission voltage response level,reception sensitivity and echo signal of the packaged CMUT were tested.The test results show that the packaged CMUT has good C-V characteristics,the maximum change of capacitance can reach 313.7 pF,the maximum transmission voltage response level is 163.83 dB@2 MHz,and the maximum reception sensitivity is-228.27 dB@1 MHz.Thus,it has good ability to transmit and receive ultrasonic waves in underwater environment.The research results provide a theoretical and practical basis for the design and package of the high-density CMUT array and underwater ultrasonic detection.