A fast-pulse oscilloscope calibration system

A system is described for calibrating high-bandwidth oscilloscopes using pulse signals. The fast-pulse oscilloscope calibration system (FPOCS) is to be used to determine the step response parameters for digitizing oscilloscopes having bandwidths of /spl sim/20 GHz. The system can provide measurement traceability to standards maintained at the U.S. National Institute of Standards and Technology (NIST). It comprises fast electrical step generation hardware, a personal computer (PC) and software, and a reference waveform, i.e., a data file containing an estimate of the step generator output signal. The reference waveform is produced by prior measurement by NIST of the step generator output signal (calibration step signal). When the FPOCS is in use, the calibration step signal is applied to the device under test, which is an oscilloscope sampling channel. The measured step waveform is corrected for timebase errors, then the reference waveform is deconvolved from it. The results are impulse, step, and frequency response estimates, and their associated parameters (e.g., transition duration, transition amplitude, -3 dB bandwidth) and uncertainties. The system and its components are described, and preliminary test results are presented.