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 similar
to 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.
