应用于微电容超声换能器的信号处理电路设计  

Design of a signal processing circuit for capacitive micro-machined ultrasonic transducer

作　　者：梁伟健 张文栋[1] 何常德[1] 郝聪聪 

机构地区：[1]中北大学仪器科学与动态测试教育部重点实验室,太原030051

出　　处：《应用声学》2018年第2期287-291,共5页Journal of Applied Acoustics

基　　金：国家杰出青年科学基金(61525107);国家重点研发计划(2016YFC0105004)

摘　　要：针对微电容超声换能器的输出信号特征及检测要求,文中设计了换能器的微弱信号处理电路,包括基于跨阻的微弱电流信号检测和多重反馈带通滤波电路。通过搭建水下测试平台,对电路性能及功能进行实际测试,并进行水下测距实验。实验结果表明,该电路可对微电容超声换能器输出的400 k Hz信号进行检测放大与滤波;电路的线性度为0.18%,滤波电路中心频率为396 k Hz,带宽为55 k Hz。该电路可用于CMUT的接收信号处理并应用于超声测距及成像的前端信号处理。A weak signal processing circuit is designed in this paper, which aims at the weak output signal of the capacitive micro-machined ultrasonic transducer(CMUT) and detecting demand, including weak current signal detection based on trans-impedance amplification and multi feedback band pass filter(BPF). Through the constructed of underwater test system, the circuit performance and distance measurement experiments were conducted. The experimental results show that the circuit can detect and amplify the 400 k Hz output signal of CMUT. The linearity of the circuit is 0.18%, and the center frequency of the filter circuit is 396 k Hz with the bandwidth of 55 k Hz. The circuit can be used for CMUT's received signal processing and applied to front-end signal processing for ultrasonic ranging and imaging.

关 键 词：电容式微机械超声换能器 微弱信号检测 信号调理电路 超声测距 

分 类 号：TN911.71[电子电信—通信与信息系统]