电容式超声换能器小信号等效电路建模与仿真  

Modeling and simulation of capacitive ultrasonic transducer small equivalent circuit

作　　者：王红亮[1] 蔚丽俊 刘涛 吕云飞 Wang Hongliang;Yu Lijun;Liu Tao;Lyu Yunfei(National Key Laboratory for Electronic Measurement Technology,North University of China,Taiyuan 030051,China)

机构地区：[1]中北大学电子测试技术国家重点实验室,太原030051

出　　处：《电子测量技术》2021年第5期155-160,共6页Electronic Measurement Technology

基　　金：国家重点研发计划项目(2018YFF01010500);国家重大科研仪器研制项目(61927807);山西省“1331工程”重点学科建设计划经费(1331KSC)资助。

摘　　要：为了进一步分析优化电容式超声换能器(CMUT)的性能,建立了CMUT微元和CMUT阵元的等效电路模型,并进行了等效电路仿真。首先推导了CMUT微元小信号等效电路模型,然后在射频电路仿真软件ADS中建立CMUT微元的等效电路进行仿真,分析了施加不同幅值、周期的交流电压对CMUT微元发射特性的影响。分析发现,交流电压幅值越大、持续周期越长,CMUT微元的振动位移和输出声压越大,发射性能越好。此外,结合互辐射阻抗,推导了CMUT阵元等效电路模型,通过ADS仿真分析了不同微元大小、间距、数目CMUT阵元的频率特性。结果表明,微元大小、间距、数目均会对CMUT阵元的频率产生影响,以上分析结果为CMUT的设计和测试提供了理论参考。In order to further analyze and optimize the performance of capacitive ultrasonic transducer(CMUT), the equivalent circuit models of CMUT cell and CMUT array were established, and the equivalent circuit simulation was carried out. First, CMUT small signal equivalent circuit model was deduced, and then the circuit simulation software ADS was used to establish CMUT cell equivalent circuit for the calculation. The influence of different amplitudes and periods of AC voltage on the emission characteristics of CMUT cell was analyzed. The results show that the larger the amplitude and duration of AC voltage, the larger the vibration displacement and output sound pressure of the CMUT cell, and the better the emission performance. In addition, the equivalent circuit model of CMUT array was derived based on the mutual radiation impedance, and the frequency characteristics of CMUT array with different cell sizes, spacing and numbers were analyzed by ADS simulation. The results show that the size, spacing and number of cells all affect the frequency of CMUT array. The above analysis results provide theoretical reference for the design and testing of CMUT.

关 键 词：电容式超声换能器 小信号等效电路 阵元等效电路 辐射阻抗 发射特性分析 频率响应分析 

分 类 号：TB552[理学—物理]