Stochastic Analysis of Braided-Shielded TWP/Twinax Cables with Random Nonuniform Shield Parameters

A generalized model for a nonuniform braided-shielded twisted wire pair (TWP) is formulated to investigate the effect of the nonuniformities of the braided shield on its shielding effectiveness performance. Since the apertures of the braided shield are exposed to shape deformation and also their location on the shield is irregular, they are considered to be random variables rather than deterministic values. Therefore, the effect of non uniformities of the braided shield on the induced common-mode (CM) and differential-mode (DM) currents of braided-shielded TWP and twinax cables are investigated by using the Monte Carlo method, where the probability density functions of the CM and DM currents are also generated. It is shown that TWP has a significant advantage as compared to the untwisted one in reducing the interference due to the nonuniformities of the braided-shield structure.