Measurement Technique for Air Capacitance Standards for the Accurate Measurement of Electrical Components using Impedance Analyzers

A measurement technique for a commercial four-terminal (4 T) air-dielectric capacitance standard set (Keysight 16380A) for frequencies from 1 kHz up to 13 MHz was developed for the accurate calibration of impedance analyzers. The technique consists of a measurement of capacitance at 1 kHz using a precision bridge, seven measurements of one-port driving point impedance (DPI) over 30 MHz using a vector network analyzer (VNA), and various numerical calculation procedures for parasitic component estimation and uncertainty propagation. The contribution from parasitic components in the frequency range of interest (FRI) from 1 to 13 MHz was estimated by extrapolation from the measured impedance using a VNA. A linear model for parasitic components was employed to extrapolate DPIs for a reliable estimation. The uncertainty of the calibration was estimated using Monte-Carlo (MC) simulation. The developed technique demonstrated better efficacy than others for the calibration of 100 pF and 1000 pF standards in FRI by applying simple, but reliable linear extrapolation models and Monte-Carlo (MC) simulation for uncertainty evaluation.