Efficient Modeling of Skin and Proximity Effects Over Ultrawide Frequency Range, Part I: Extraction of Transition Factors

Efficient modelling of both skin and proximity effects in solid and hollow cylindrical conductors over an ultrawide frequency range is performed. The transition factors (TFs), denoted by TFs, responsible for the transition property between low and high frequency regions are at first extracted using an efficient analytical technique. Then, they are applied for the development of fields within and around the conductors, respectively, leading to the definition of the other new compound TF. Therefore, the skin and proximity effects with the transition property along a wide frequency range are accurately predicted, and enclosed with compact elegant formulas. Also, it is shown that the lossy conductors cannot be always considered as equipotential surfaces during the potential derivation because they can behave as transparent surfaces to the magnetic field lines, and this concept can be explained by using the TFs properties. Moreover, the transfer impedances of a shielded multiconductor cable with hollow shields are also generalized with TFs and the skin and proximity effects included, together with the transfer impedances examined. The induced common- and differential-mode within shield multiconductor cables, due to the coupling through their hollow shield, are fast predicted accurately using the developed transition property. Finally, the proposed model is validated in comparison with both COMSOL Multiphysics and HFSS software.