李松松,平东岳,张宸宸,夏闻泽,郭中会.EMAT接收端电路的设计与优化[J].电子测量技术,2019,42(10):6-11 |
EMAT接收端电路的设计与优化 |
Design and optimization of EMAT receiver circuit |
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DOI: |
中文关键词: 电磁超声传感器 兰姆波 阻抗匹配 前置放大器 |
英文关键词:EMAT lamb wave impedance matching receiver circuit |
基金项目:辽宁省自然基金(2015020124)、辽宁省海洋与渔业厅项目(201723)资助 |
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Author | Institution |
Li Songsong | School of engineered information, Dalian Ocean University, Dalian 116023,China |
Ping Dongyue | School of Electronic Science and Technology,Dalian University of Technology,Dalian 116021,China |
Zhang Chenchen | School of engineered information, Dalian Ocean University, Dalian 116023,China |
Xia Wenze | School of engineered information, Dalian Ocean University, Dalian 116023,China |
Guo Zhonghui | School of engineered information, Dalian Ocean University, Dalian 116023,China |
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中文摘要: |
电磁超声换能器(EMAT)由于不需要耦合剂、可应用于高温环境而获得广泛关注,但是存在换能效率低、超声回波信号幅值小、容易受到噪声干扰的问题,需要对其进一步研究。根据EMAT的工作机理,通过分析超声兰姆波回波信号的特点确定了接收电路的指标,设计并优化了阻抗匹配电路、前置放大电路以及低通滤波电路,同时设计了数字带通滤波器对信号进一步处理。首先对前置放大电路进行仿真,使其具备小信号接收能力。然后采用的三级负反馈电路结构的低通滤波电路,消除空间耦合噪声。最后搭建了铝板的EMAT探伤测试系统,结果表明设计的接收电路很好地实现了兰姆波的检出,为探伤系统的研制提供了基础。 |
英文摘要: |
Electromagnetic acoustic transducer(EMAT)sensors are widely concerned because they do not need couplers and can be used in high-temperature environments. However, there are problems such as low energy conversion efficiency, small amplitude of ultrasonic echo signal, and easy to be disturbed by noise, which need to be further studied. According to the working mechanism of the EMAT, through analyzing the characteristics of the echo signal of ultrasonic Lamb determines the index of receiving circuit, design and optimize the impedance matching circuit, preamplifier circuit and low-pass filter circuit, and design the digital bandpass filter for further signal processing. Firstly, the preamplifier circuit is simulated to make it capable of receiving small signals. Then a three-stage MFB low pass filter circuit is adopted to eliminate the spatial coupling noise. The EMAT flaw detection test of aluminum plate was made and built by circuit hardware. The results show that the designed receiver circuit can detect lamb wave well, which provides a foundation for the development of the testing system. |
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