Fast and Accurate Semi-Analytical Solution to Skin and Proximity Effects in Shielded Cable Systems

In this article, the skin and proximity effects formulas of solid and hollow conductors with different radii are accurately formulated using exact expressions of electric and magnetic fields around them. Moreover, both approximation and simplification of the developed formulas are also provided for higher frequency applications, where the skin depth is significantly smaller than the conductor radius. Consequently, it is shown that these approximate expressions can help us to understand the coupling mechanisms of noncoaxial and twinax cables with hollow shields, where the transfer impedances of the shields are determined with an inner conductor located at a noncoaxial location. The coupling through a hollow shield of a twinax cable is also investigated, and the induced common- and differential-mode currents are predicted in very fast and accurate way. The proposed method is validated by making comparisons with both COMSOL Multiphysics and HFSS software with different numerical methods employed.