Waveform metrology: signal measurements in a modulated world

We review the waveform metrology program developed over many years at the National Institute of Standards and Technology. The goal of this program is to provide a measurement service capable of characterizing both temporal and frequency-domain instrumentation used with high-speed communication systems. Under our program, full waveforms as functions of both time and frequency are the target measurands. From these functional waveforms, traditional parametric descriptions can be derived. Furthermore, we give temporal waveforms and their frequency-domain representations consistent and equal consideration, with traceability to the International System of Units. To support this traceability, we emphasize voltage and current waveforms, their relationships, and the ability to transform both nominal values and their uncertainties from one domain to the other.