基于电容式微机械超声换能器的脉冲回波接收电路设计  

Design of Pulse⁃echo Receiving Circuit Based on Capacitive Micromachined Ultrasonic Transducer

作　　者：余远昱 王久江 张双 刘鑫 徐晶 李尧[1] YU Yuan-yu;WANG Jiu-jiang;ZHANG Shuang;LIU Xin;XU Jing;LI Yao(School of Artificial Intelligence,Neijiang Normal University,Neijiang 641100,China;School of Life Science and Technology,University of Electronic Science and Technology of China,Chengdu 611731,China;State Key Laboratory of Analog and Mixed-Signal VLSI,University of Macao,Macao 999078,China;Department of Electrical and Computer Engineering,Faculty of Science and Technology,University of Macao,Macao 999078,China)

机构地区：[1]内江师范学院人工智能学院,四川内江641100 [2]电子科技大学生命科学与技术学院,四川成都611731 [3]澳门大学模拟与混合信号超大规模集成电路国家重点实验室,中国澳门999078 [4]澳门大学科技学院电机与电脑工程系,中国澳门999078

出　　处：《仪表技术与传感器》2022年第7期23-27,33,共6页Instrument Technique and Sensor

基　　金：国家自然科学基金项目(U19A2082);四川省科技计划资助项目(2022YFH0110,2022JDRC0134,2021YFSC0040);中国博士后科学基金面上项目(2020M683294);内江师范学院科研团队项目(17TD03,2021TD02)。

摘　　要：电容式微机械超声换能器(CMUT)是一种新型超声换能器,具有高带宽、易与前端放大电路集成等优点,CMUT通过输出微弱的变化电流实现超声波回波检测。根据CMUT工作在发射与接收模式的特点,设计了一种具有发射开关保护功能和跨阻放大器的脉冲回波接收电路。波特图测量表明该电路的最大增益为39 dB,-3 dB带宽为24.2 MHz,涵盖了医学与工业超声检测常用的频率范围。分别对5.8 MHz和9.4 MHz的CMUT进行脉冲回波实验测试,测试结果表明:在CMUT发射模式下,该电路能够防止高压发射脉冲损坏后级的跨阻放大器电路;在CMUT接收模式下,该电路能够有效地将微弱电流信号转化为电压信号并进行放大。因此该电路能够用于CMUT的脉冲回波信号处理。The capacitive micromachined ultrasonic transducer(CMUT)is a kind of new ultrasonic transducer with the ad⁃vantages of high bandwidth and easy integration with the front⁃end amplifier circuits.CMUT can detect ultrasonic echo waves by generating weak changing currents.According to the characteristics of CMUT working in transmit and receive mode,a pulse echo receiving circuit with a protect transmit switch and a transimpedance amplifier was designed.Bode plot measurement shows that the maximum gain of the circuit is 39 dB,and the-3 dB bandwidth is 24.2 MHz,which covers the common frequency range of medical and industrial ultrasonic testing.The 5.8 MHz and 9.4 MHz CMUT were tested by pulse⁃echo experiments,respectively.The test results show that in the CMUT transmission mode,this circuit can prevent the high⁃voltage transmission pulses from dam⁃aging the transimpedance amplifier circuit of the subsequent stage;in the CMUT receiving mode,this circuit can effectively con⁃vert the weak currents into amplified voltages.Therefore,this circuit can process the CMUT pulse⁃echo signals.

关 键 词：电容式微机械超声换能器 微弱电流检测 跨阻放大器 脉冲回波 超声回波接收 高带宽 

分 类 号：TN492[电子电信—微电子学与固体电子学]