Optimized uncertainty estimation in the calibration of two port networks transmission coefficient

The uncertainty evaluation in the calibration of two-port networks transmission coefficient is here dealt with. Attention is focused on the covariance contribution of the uncertainty expression and on the effect of mismatch terms. To this aim, the approach suggested by the Guide for the expression of uncertainty in measurement (GUM) is discussed, and solutions are proposed aimed at optimally combining all the uncertainty terms to be considered. To confer reliability and generality to the research activity, a number of experiments are conducted through a proper test bench. The ultimate goal is to provide practical hints for improving the calibration accuracy of two-port networks transmission coefficient, and simplifying the derivation of the standard uncertainty.