Uncertainty of the measurement of the frequency dependence of four-terminal pair capacitance with a four-channel...

We recently overhauled the calibration service for the frequency dependence of four-terminal pair air capacitors provided by the National Institute of Standards and Technology to its customers. In the past, the calibration was performed with a dual-channel vector network analyzer, requiring nine different connections to the standard with a rigid 7 mm microwave line. The new method streamlines the measurement, as each standard can be measured by simply connecting four coaxial lines between it and a four-channel network analyzer. Here, we discuss the uncertainty budget of this new procedure. Due to the four-terminal pair definition, the measurements are much less dependent on the connectors and the uncertainty in individual scattering parameters than other S parameter measurements.