A-posteriori Estimation of Random Uncertainty for the Reflection Type Q-factor Measurements

Authors

  • Darko Kajfez Department of Electrical Engineering, University of Mississippi, University, MS, 38677

Keywords:

Least squares data fitting, measurement uncertainty, Q-circle, unloaded Q factor, Smith chart

Abstract

A frequently used Q factor measurement procedure consists of determining the values of the input reflection coefficient vs. frequency with the use of a network analyzer, and processing the measured values with a data-fitting procedure to evaluate the location and the size of the corresponding Q-circle. That information is then used to compute the value of the loaded and unloaded Q factors and the coupling coefficient of the resonator being tested. This paper describes a novel method of post-processing the measured data, which also provides information on the uncertainty of the obtained results. Numerical examples show that this a-posteriori procedure can not only provide the uncertainty estimates but also improve the accuracy of results, even in the presence of a significant level of random measurement noise.

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Author Biography

Darko Kajfez , Department of Electrical Engineering, University of Mississippi, University, MS, 38677

Darko Kajfež received the Dipl. Ing. degree in Electrical Engineering from the University of Ljubljana in 1953, and the Ph.D.degree from the University of California, Berkeley in 1967. Between 1950 and 1963 he worked with companies “IEV,” “Rudi Čajavec,”and “Zavod za Avtomatizacijo” in Yugoslavia, primarily in microwave communications and radars. From 1963 to 1966 he was a Research Assistant at the Electronics Research Lab at University of California, Berkeley. Between 1967 and 2000 he was first Associate Professor and later Professor with the Department of Electrical Engineering, University of Mississippi in Oxford, MS. His research interests are in microwaves and antennas.

References

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Published

2020-10-01

How to Cite

[1]
Darko Kajfez, “A-posteriori Estimation of Random Uncertainty for the Reflection Type Q-factor Measurements”, ACES Journal, vol. 35, no. 10, pp. 1105–1112, Oct. 2020.

Issue

2020: Vol 35 Iss 10

Section

Articles