A Wide Frequency Range Relationship Between Transfer Impedance of Braided Cables and Shielding Effectiveness of Corresponding Plate Shields

Electromagnetic shielding properties of cables can be characterized by transfer impedance and planar shields by shielding effectiveness. Both properties are associated with measurement techniques, which have their own frequency limitations. The concept of
sheet transfer impedance
is proposed to allow the transition of complex cylindrical structures to planar configurations through a simple and efficient formula. Three-dimensional full-wave simulations of the periodic pattern of plate shields and planar braid shields are performed and compared to cylindrical analytic models. The proposed formula is validated by a good concordance between shielding effectiveness and transfer impedance values. Consequently, the industrial qualification tools such as transfer impedance and shielding effectiveness can then be linked to each other, and the two techniques can be used complementarily to cover a wide frequency range. Moreover, complex cylindrical structures can be more easily simulated using planar periodic patterns.