基于四参数正弦拟合的放大器延迟时间的精确测量

The Precise Measurement Method for Delay of Amplifiers Based on Four-parameter Sinusoidal Curve-fit Method

针对放大器延迟时间测量时信号幅度相差悬殊的问题,提出了四参数正弦拟合测量方式,以相位差转换成时间差予以实现。对其中的相位周期性带来粗大误差问题,负值幅度带来相位粗大误差问题,测量系统自身通道间延迟修正问题等,进行了分析讨论,并给出了解决方案。对测量结果的不确定度进行了分析。在实际应变放大器上的一组实验结果,验证了所述方法的有效性与可行性。并且发现,放大器的延迟具有内在稳定性,与激励信号的幅度、频率、波形等均无关系。该方法可用于放大器、滤波器、衰减器等线性电路延迟的测量分析。

Aiming at the problems in measurement of delay time of amplifiers,such as the large difference between two sampling signals,a novel measurement method based on four-parameter sinusoidal curve-fit method was presented.Based on turning the phase difference into time difference,the delay of amplifiers was measured.Some problems about measurement were discussed.They were the coarse errors of periodic phases,big errors of negative amplitude,modification of delay between two sampling channels of data acquisition its self,all of them were discussed and analyzed in details,and the resolution method were given out.The measurement uncertainty was analyzed.In experiment,both the validity and the feasibility of the measurement method were proved.The experiment showed that the delay of amplifiers has inherence stability itself,it is indifferent to the stimulus frequency,amplitude,and waveforms.The delay measurement method above can be applied in all the measurement of delay of the amplifiers,filters,attenuators,etc.