Study of removing the influence of microwave reflection in the time domain measurement data of the characteristic impedance of transmission line

This paper studied two methods to remove the influence of the microwave reflection in the time domain measurement data of the characteristic impedance of transmission line. Usually, people choose the best measurement region according to the IPC procedure to remove the influence of microwave reflection. Although this method is simple and effective, it inevitably removes plenty of effective measurement data. So it results in the accuracy of the characteristic impedance measurement is not high enough. According to the basic theory of measurement and the feature of measurement waveform, this paper proposed the threshold method of amplitude and mode method of amplitude to remove the influence of the microwave reflection. Analysis and calculation results showed that the two methods could effectively remove the influence of microwave reflection and improve the accuracy of calculation results of the characteristic impedance of transmission line.