Calculation of per-unit-length parameters for shielded and unshielded twisted pair cables

The deployment of multimedia data transmission is increasing, digital subscriber line technology (xDSL) and other systems are widely used on the telecommunication access network. Conveying such services requires higher data rates, consequently higher bandwidths, and operating frequencies. So, the modelling of the cables is essential to study the disturbing electromagnetic phenomena. Analytical expressions for P.U.L. parameters of finite length twisted pair lines are derived, and verified by the measurement in this paper. These expressions give the capacitances and the inductances values in every point of the cable