Int. J. Metrol. Qual. Eng.
Volume 3, Number 1, 2012
|Page(s)||29 - 37|
|Published online||26 September 2012|
Importance and estimation of mismatch uncertainty for RF parameters in calibration laboratories
Amorphous and Microcrystalline Silicon Solar Cells, CSIR-National
Physical Laboratory, New
2 Electrical Standards, CSIR-National Physical Laboratory, New Delhi, India
⋆ Correspondence: email@example.com
Received: 17 March 2012
Accepted: 24 March 2012
A number of calibration techniques are used in Radio Frequency (RF) calibration for power, attenuation and impedance parameters. Mismatch uncertainty plays a major role in these measurements and in estimation of combined uncertainty according to ISO/IEC 17025:2005 and GUM document. Formulas to evaluate the mismatch uncertainty in terms of reflection coefficient, voltage standing wave ratio and scattering parameters have been evaluated earlier and are being used in RF calibration. The present paper summarizes the mismatch formulas previously studied and the modified ones suitable to the measurement system and techniques available today. For power and attenuation calibration in the particular frequency range, an establishment of traceability for one-port measurement in the same frequency range is required. The methods to reduce and control this uncertainty component and their limitations are also discussed forbest measurements practices in the calibration laboratories.
Key words: Mismatch uncertainty / RF attenuation / RF power / impedance traceability / vector network analyzer
© EDP Sciences 2012
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.