Automatic Calibration of Systematic Errors in Fast Pulse Measurements

摘要

In calibrating a precision time-interval measuring instrument such as a counter, one needs two signals separated by a known time interval at the trigger level. The waveforms of these sources should imitate as much as possible the signals to be measured in amplitude, slope, transition time etc. This paper describes a calibrator which splits a given input waveform linearly and passively into two signals which are either identical or mirrored about a given trigger level. These are measured by the counter either directly or swapped via rf relays. Through an algorithm of measurements (via HPIB) and computation, counter systematic errors can be extracted for any particular waveform type. Accuracy of the calibrator itself is better than 10 Ps, traceable to the NBS, and for the counter, better than 100 PS after calibration.