Contact MTT-11 Webmaster
Nuno Borges Carvalho
Last Updated 17-02-2008

Errors and Uncertainties

for VNA Measurements

Top | Moderator | FAQ | Bibliography

Yahoo! MTT-11 Errors and Uncertainties for VNA Measurements Newsgroup focuses on methods that can be used to evaluate errors and uncertainties in VNA and VNA-related measurements, particularly at high frequencies (1 kHz to 1 THz).

How It Works

To join this forum, simply insert your e-mail above, and then click on the "Join Now" button, and then follow the instructions for signing up to be a member of Yahoo! Groups. The only requirement to join this newsgroup is membership in IEEE.

In order to expedite your subscription, please do one of the following:
(1) Send the moderator your IEEE number, or
(2) Send the moderator your name if you are an MTT-S member.

Warning: Do not register using an "ieee.org" alias. The IEEE server filters Yahoo! emails.

Once you've been approved you can ask the moderator, who is an expert in this field (see the section below), a question. He or she will then either answer your question, send you to an existing thread that has previously answered your question, or ask somebody else to respond. You can also respond to a previous message or browse through the archives by clicking on the link at the top of the page.

Once you've joined this forum, feel free to ask a question to the moderator, or respond to a previous message by sending an email to:

mtt-11-uncertainty@yahoogroups.com.

Top | Moderator | FAQ | Bibliography

Moderator

Nick M. Ridler received the B.Sc. degree from the University of London in 1981. He has since spent more than 25 years working in both industrial and government scientific research laboratories. Nick is currently employed by the UK's National Physical Laboratory and is responsible for RF and microwave measurement activities. This includes managing the national standard facilities for VNA measurements. His current research activities include: measurements at millimeter wavelengths (to 300 GHz and beyond); RF Printed Circuit Board measurements; and, evaluating the uncertainty of measurements. Nick is a Chartered Engineer, Fellow of the Institution of Engineering and Technology (formerly the Institution of Electrical Engineers, IEE) and a Senior Member of the IEEE. You can contact Nick directly at nick.ridler@npl.co.uk.

Yeou-Song (Brian) Lee received his Ph.D. degree in Electrical and Computer Engineering from the State University of New York at Buffalo. Brian was involved with the development of industrial, scientific, and legal metrology nationally and internationally during his employment with the Center for Measurement Standards, Industrial Technology Research Institute (Taiwan) from 1990 to 1997. He started to manage the HP and Agilent Golden Gate standards laboratory in 1997. His areas of focus were microwave standards, calibration, uncertainty analysis and accreditation. In 2001, Brian was hired by the Anritsu Company to manage the metrology program. He is involved with uncertainty analysis, calibration services, accreditation, product specification, calibration design, and quality. Brian is a Senior Member of the IEEE and the American Society of Quality.

David V. Blackham received a B.S.E.E. degree from Brigham Young University, Provo, UT., a M.S.E.M degree from Stanford University, Stanford, CA., an M.S.E.E. degree from National Technological University, Fort Collins, CO., and a Ph.D. from the University of Leeds, Leeds, U.K. He started working for Hewlett-Packard in 1979 and now works for Agilent Technologies. His work has included microwave sources, RF and microwave vector network analyzers, scalar detectors and bridges and microwave characterization of materials. His current work focuses on error correction and measurement accuracy in vector network analyzers.

Top | Moderator | FAQ | Bibliography

Frequently Asked Questions

Coming soon

Some Definitions

"Accuracy" – closeness of the agreement between the result of a measurement and the true value of the quantity being measured

 "Error" – result of a measurement minus the true value of the quantity being measured

 "Repeatability" – closeness of agreement between the results of successive measurements of the same quantity under the same conditions

"Uncertainty" (of measurement) - parameter, associated with the result of a measurement that characterizes the dispersion of the values that could reasonably be attributed to the quantity being measured. [Alternative description – the uncertainty of a measurement provides an interval that is likely to contain the ‘true value’ of the quantity being measured.]

 "Traceability" – property of the result of a measurement, or the value of a standard, whereby it can be related to stated references, usually national or international standards, through an unbroken chain of comparisons all having stated uncertainties

Top | Moderator | FAQ | Bibliography

Selected Bibliography

Disclaimer: This is not an exhaustive bibliography. If you would like to suggest a suitable paper to be listed here, please email the moderator.

General guidance

ISO/IEC Guide 98:1995, “Guide to the expression of uncertainty in measurement”, International Organization for Standardization.
(Available from www.iso.org/iso/store - currently unavailable.)

B N Taylor and C E Kuyatt, "Guidelines for evaluating and expressing the uncertainty of NIST measurement results", NIST Technical Note 1297, 1994.
(Available from http://physics.nist.gov/Pubs/pdf.html.)

"Expression of the uncertainty of measurement in calibration", European co‑operation for Accreditation, publication reference EA-4/02, December 1999.
(Available from http://www.european-accreditation.org/n1/doc/EA-4-02.pdf.)

"The Expression of Uncertainty and Confidence in Measurement", United Kingdom Accreditation Service, M3003, Jan 2007.
(Available from http://www.ukas.com/Library/downloads/publications/M3003.pdf.)

Application specific guidance

"Guidelines on the evaluation of Vector Network Analysers (VNA)", EURAMET/cg-12/v.01 (previously EA-10/12), July 2007.
(Available from http://www.euromet.org/euramet/Calguides/EURAMET-cg-12.01_Guidelines_on_Evaluation.pdf.)

N M Ridler and M J Salter, "An approach to the treatment of uncertainty in complex S-parameter measurements", Metrologia, 39(3), pp 295-302, June 2002. 
(Available from http://www.iop.org/EJ/article/0026-1394/39/3/6/me2306.pdf.)