摘要
本文提出了一种提高电磁层析成像测量信号信噪比的新方法。在电磁层析成像的前端测量电路中,最重要的一环是一个含有低通滤波器的相敏解调电路,当激励源从一个线圈切换到另一个线圈时,接收电压值发生变化,从而引起一个暂态响应过程。通常,测量和数模转换要等暂态响应过程完成、电压信号稳定后进行。本文提出了一种利用分析暂态相应过程中所含的信息而提高电磁层析成像测量信号信噪比的新方法。仿真和实验结果肯定了这种方法的有效性,测量到的电感值的标准方差下降多于50%。
This paper presents a novel method to increase the signal to noise ratio in MIT data acquisition by exploiting transient process analysis.In front-end circuits for inductance measurements in MIT,a critical step is the phase sensitive demodulation,which includes a low pass filter.When the excitation source is switched from one coil to the next,a transient process occurs as the received voltage level changes.Normally,data acquisition takes place until the transient process finishes and the voltage level becomes nearly constant.In this paper,a method is proposed to increase the signal to noise ratio or the frame capture rate by exploiting the information embedded in the transient process.Simulation and experimental tests have confirmed the validity of the method; standard deviations of the measured inductance decrease more than 50%.
出处
《电子测量与仪器学报》
CSCD
2009年第S1期1-3,共3页
Journal of Electronic Measurement and Instrumentation
关键词
电磁层析成像
暂态响应
信噪比
数据获取
MIT
transient process
signal to noise ratio
imaging
data acquisition
