Effects of electric contact failure on signal transmission in unmatched circuits

It is found that one of the most important reasons for high error code rates in optical communication systems is the contact failure of the coaxial electrical connectors installed in the systems. The influences of the contact failure on the digital signal transmission in ideal circuits have already been studied theoretically and experimentally. Based on those results, this paper further studies theoretically the effects of contact failure on the digital signal transmission in unmatched circuits, which can happen widely in practical applications. Derivation shows that the effects of contact failure in unmatched circuits on the signal transmission are very complex. Multi-reflection of the signals may occur in the circuit, and the probability of occurrence of error codes can be increased significantly