Simple relations between shielding effectiveness and transfer impedance/admittance for cables

摘要

An approach to the description of common-mode shielding performance that is based on the concept of shielding modes is proposed. A shielding mode consists of a combination of driving field (magnetic or electric) and shield-leakage parameters (transfer impedance or admittance). Using the shielding mode concept, dominant coupling modes can be immediately determined, individual shielding mode curves appear relatively insensitive to changes in cable load values, and shielding curve behavior can be more easily predicted for changes in cable length and other parameters. The use of the shielding mode concept also clarifies relationships between shielding effectiveness and transfer impedance/admittance parameters. Using the shielding mode concept, a set of simple relations between these important shielding parameters is derived.