Pulsed S-parameter measurements: on resolution, and uncertainty

As the timing and uncertainty requirements continue to increase for pulsed S-parameter measurements, it may be worth revisiting the effects of time resolution, time duration (either in terms of number of pulses or period) and measurement architecture on uncertainties. The advent of highly linear, faster digitizers has enabled improved resolution for constant uncertainty, sometimes at the expense of duration or range of pulse periods allowed but data processing changes can get around a number of those issues. A newer structure will be presented allowing resolutions down to 2.5ns simultaneously with pulsed periods in the 100 ms range and transmission uncertainties on the scale of 0.1 dB/1 deg to 40 GHz and higher depending on the setup. The effects of a number of the structural options on uncertainty are discussed along with complications introduced by additional pulse parameter dependencies.