Analytical Modeling of Shielded Cable with Pigtail Termination

Abstract

In this paper, general considerations of the pigtail impact on the cable’s shielding effectiveness is presented. Since the well-known transfer impedance is defined especially to characterize the cable shield itself, it is insufficient to describe the shielding performance of the entire cable assembly, where the shield is necessarily grounded at the terminal points. Learning from the defining method of transfer impedance, this paper proposes a novel definition “Equivalent Transfer Impedance” to quantify the pigtail impact. Further, considering the equivalent transfer impedance of the pigtail section, the overall transfer impedance of the entire cable is given based on the transmission line cascade approach. At the end, the line injection method is employed to test the transfer impedance of the cable which has pigtail terminations. The measurement results are found to be in strong agreement with the theoretical calculations, which implies the proposed analytical model is effective to describe the pigtail impact.