An Accurate Wide-Band Automatic Waveform Analyzer

This paper presents accurate and quantitative measurements of waveform parameters and eye pattern which is important as an evaluation parameter of digital transmission characteristics in the development of a wide-band automatic waveform analyzer from dc to 10 GHz. The measurements and-error of transfer characteristics by using FFT is also described. New techniques are adopted in averaging, calibrating, and compensating the time axis for the accurate measurements. Relevant software offers a method for quantitative measurement. The methods have made it possible to measure the waveform parameters which are about ten times more accurate than can be obtained through conventional oscilloscopes. In the quantitative evaluation of eye pattern, the measuring error has been improved from 10 down to 2 or 3 percent as compared with measurements by sight using a conventional oscilloscope. An equation which gives the approximate value of the error in the measurement of transfer function in the frequency domain from the time-domain pulse response is shown and confirmed to correspond with the actual case.