Simple Model to Predict RS103 Responses from Single UTP Circuits

Manufacturing practices when building unshielded twisted pair (UTP) cables can cause the lengths of the half twists to be random, which then affects the RS103 responses of such cables. This paper uses a simple transmission line model to extract the RS103 responses from unshielded twisted pair cables when the half twists are nominally either 0.5 ″ or 0.125 ″ and when the lengths of the half twists are uniformly distributed between +/-25% or +/5% about the given nominal length, and when the length of the cable is 23 inches. In addition, two cable routing profiles are considered.