An efficient analytical model for the transfer impedance and admittance of a noncoaxial/twinax braided-shielded cable with apertures on its sheath is proposed by generalizing the old Vance's and Kley's formulas, and it is derived using the complex analyses with an appropriate conformal mapping. Therefore, such a noncoaxial cable is converted into a coaxial one which can be studied using the traditional multiconductor transmission line method. It is shown that the aperture inductance is related to the position of the inner conductor and the radial position of each aperture on its sheath. In addition, the modal domain analysis is performed to obtain the common-mode (CM) and differential-mode (DM) transfer impedance/admittance of the twinax braided-shielded cable, with CM and DM currents inside the inner conductors examined. The proposed model is validated by comparing the results with that obtained by the method of moments (MoM)-based commercial software FEKO. It is found that the uniform distribution of the apertures on the sheath reduces the induced DM current significantly.

中文翻译：

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非同轴/双轴编织屏蔽电缆传输阻抗和导纳的高效分析模型


通过推广旧的 Vance 和 Kley 公式，提出了一种针对护套上有孔的非同轴/双芯编织屏蔽电缆的传输阻抗和导纳的有效分析模型，并使用适当的保形映射进行复杂分析来推导该模型。因此，将这种非同轴电缆转换为同轴电缆，可以使用传统的多导体传输线方法进行研究。结果表明，孔径电感与内导体的位置及其护套上每个孔径的径向位置有关。此外，还进行模域分析，以获得双轴编织屏蔽电缆的共模 (CM) 和差模 (DM) 传输阻抗/导纳，并检查内导体内的 CM 和 DM 电流。通过将结果与基于矩量法（MoM）的商业软件 FEKO 获得的结果进行比较，验证了所提出的模型。研究发现，护套上均匀分布的孔径显着降低了感应DM电流。