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Abstract

This thesis presents a method for correcting reflection coefficients measurements using network analysers of the heterodyne type.
The calibration process presented here utilizes three standard loads at each frequency of calibration in order to establish the systematic system error model. Having corrected the results for the systematic errors in the measurement, random errors still remain which cannot eliminated by any procedure because they are random in their nature. So a statistical approach, has been used to estimate the residual error after corrections have been applied.
A statistical analysis is carried out on repeated measurements of a standard at the same frequency for each of the standards used in the calibration to estimate the standard error in the magnitude and phase for a single network analyser measurement. Making use of a random number generator available in the computer this deviation is applied to a set of theoretically perfect correction measurements and the resultant reflection coefficient calculated. The entire calibration process is repeated many times in a loop, and on each occasion a random value is assigned to the phase angle and magnitude, within limits corresponding to each error source. The uncertainty on a measurement reflection coefficient is then estimated by applying the technique of bivariate distribution to the random variable.
From these calculations the relation of residual error in magnitude and phase is estimated for different magnitudes of reflection coefficient. These are compared with values obtained by other authors.
In order to test the validity of the calibration procedure a stable load was measured through different mismatching transducers and it was shown that the calibration prrocedure was effective even for the poorest transition.

Publication Type:	Thesis (Doctoral)
Subjects:	T Technology T Technology > TK Electrical engineering. Electronics Nuclear engineering
Departments:	School of Science & Technology > Engineering > Electrical & Electronic Engineering School of Science & Technology > School of Science & Technology Doctoral Theses Doctoral Theses

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