雙門選超聲波收發模擬電路的設計

李卞俊,楊　錄,張艷花

(中北大學 信息與通信工程學院,山西 太原　030051)

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雙門選超聲波收發模擬電路的設計

李卞俊,楊錄,張艷花

(中北大學 信息與通信工程學院,山西 太原030051)

摘要針對現有模擬板中存在冗余的電容導致建波信號拖尾較長,致使超聲信號經模擬板處理后分辨率低的問題,提出了一種以差分接收、雙門選回波處理硬件電路設計。在檢波放大之前設計一個門選電路,直接從全波信號中選取缺陷信號,避免了界面波經過檢波放大電路后,形成拖尾淹沒缺陷信號,提高了接收電路信號的可靠性。文中從硬件方面介紹了接收電路的調整。實驗表明,電路性能穩定、精度高、成本低,并具有良好的應用前景。

關鍵詞超聲波收發;差分接收;雙門選;高精度

Design of Double-gated Ultrasonic Analog Circuits

LI Bianjun,YANG Lu,ZHANG Yanhua

(School of Information and Communication Engineering,North Central University,Taiyuan 03005,China)

AbstractA hardware circuit design characterized by differential-receiving,double-gated and peak-keeping is proposed for the long tail of detection signals and the low resolution of ultrasonic signals caused by redundancy capacitors existing in the analog board.Flaw signals are selected from the full-wave signal by designing a gate-select circuit in front of the detecting circuit to remove the tail of detection signal effectively and improve the reliability of ultrasonic signal.This article introduces the adjustment of receiving circuit in terms of hardware.The experiment shows the system has stable performance,high precision,and large range,and with a broad application prospect.

Keywordsreceive and dispatch of ultrasonic;differential receiver;double-gated;high-precision

超聲探傷是利用材料及其缺陷的聲學性能差異對超聲波傳播波形反射情況和穿透時間的能量變化來檢驗材料內部缺陷的無損檢測方法[1]。

在超聲探傷系統中,超聲收發模擬電路設計的好壞直接影響回波信號的可靠性和超聲探傷系統的精度,所以超聲收發模擬電路在超聲探傷系統中起著重要的作用。針對現有模擬板中存在冗余的電容導致建波信號拖尾較長,致使超聲信號經模擬板處理后分辨率低的缺點,設計了一種高精度、高分辨率的超聲波發射接收電路。

1超聲波檢測方法

超聲波探傷方法按原理分類,可分為脈沖發射法、穿透法和共振法,脈沖反射法包括缺陷回波法、底波高度法和多次底波法[2]。……