Cox, M G; Dainton, M; Harris, P M; Ridler, N M; Young, P R (1999) A generalised treatment of the uncertainty in calibration and measurement of vector-indicating microwave reflectometers. NPL Report. CETM 10
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Abstract
In this report we consider the uncertainty in calibration and measurement for vector-indicating microwave reflectometers.
The voltage reflection coefficient for a given measurement configuration is treated as a complex measurand. The uncertainty in measurement can be perceived as an uncertainty ellipse on each measured point in the complex plane with semi-axes and orientation depending on the errors in the real and imaginary parts of the reflection coefficient and their correlation.
In the first instance, we show how the system can be calibrated using the minimum number of standards (three) by solution of the resulting deterministic problem. We then show how the calibration uncertainty can be reduced by solving the over-determined system where more than three standards are considered. This solution involves the use of Generalised Distance Regression, as performed on complex values, to obtain the complex-valued calibration constants as used in the subsequent measurement process.
Item Type: | Report/Guide (NPL Report) |
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NPL Report No.: | CETM 10 |
Subjects: | Electromagnetics Electromagnetics > RF and Microwave |
Last Modified: | 02 Feb 2018 13:18 |
URI: | http://eprintspublications.npl.co.uk/id/eprint/1117 |
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