Andrew D. Koffman

Publications

Uncertainty of the measurement of the frequency dependence of four-terminal pair capacitance with a four-channel vector network analyzer

March 31, 2025

Author(s)

Stephan Schlamminger, Andrew Koffman, Yicheng Wang

We recently overhauled the calibration service for the frequency dependence of four-terminal pair air capacitors provided by the National Institute of Standards

Uncertainty Analysis of Vector Network Analyzer Measurements of four terminal-pair air capacitors

July 8, 2024

Author(s)

Stephan Schlamminger, Yicheng Wang, Elise Knutsen, Andrew Koffman

Traditionally, vector network analyzer (VNA) measurements have been used to determine the frequency dependence of four terminal pair air capacitors. Recently

Four terminal-pair measurements of ceramic capacitors

June 28, 2024

Author(s)

Stephan Schlamminger, Yicheng Wang, Andrew Koffman, Jordan Love

Expanding on our previous work on four terminal-pair air capacitors, we present a model for the frequency-dependent capacitance of ceramic capacitors for values

Comparison of a 1 nF Capacitor with a 1 kΩ Resistor Using a Digital Impedance Bridge

March 27, 2024

Author(s)

Yicheng Wang, Stephan Schlamminger, Dean G. Jarrett, Alireza Panna, Andrew D. Koffman

This paper reports our effort to improve a digital impedance bridge. The limit of the bridge resolution and stability is less than 3 parts in 10^9 for the

Measurement of the frequency dependence of four terminal-pair air capacitors with a vector network analyzer

October 6, 2023

Author(s)

Stephan Schlamminger, Andrew D. Koffman, James W. Schmidt, Bryan C. Waltrip, Yicheng Wang

Four terminal-pair air capacitors are important transfer standards to calibrate LCR meters up to a frequency of 10 MHz. We report a simple and new method to

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Andrew D. Koffman (Fed)

Publications