Tecniche riflettometriche per la localizzazione di guasti su cablaggi avionici

This paper analyses the performance of the Time Domain Reflectometry (TDR) when it is applied to the location of faults on avionic cables. Different types of defects, which can arise on coaxial cables, are modelled and their reflection coefficients are calculated. The results, validated by experimental data, are compared to the typical noise that affects this kind of measurement to assess the sensitivity of the technique. On the basis of these results, in order to improve the performance of TDR and locate also small faults, a new data processing technique based on the comparison with a reference measurement and the use of the statistical correlation is introduced. The analysis is then extended to other types of cables, such as multiwire and twisted cables, where the effect of cable and mismatching losses can limit the dynamic range of the measurement