Assessment of Broadband Shielding Effectiveness of Composite Panels for Protective Enclosures

The article investigates the shielding effectiveness (SE) of a metallic enclosure with a multilayer composite cover over a wide frequency range, from near-field magnetic shielding (1 Hz-1 MHz) to far-field electromagnetic shielding (4-14 GHz). Two enclosures are considered: a conductive enclosure made of aluminum and a magnetic enclosure made of steel. The multilayer composite is a trilayer combining a thin conductive layer of graphene and a thin magnetic layer of a Fe-Ni alloy on either side of a fiberglass plate. To determine the SE of these enclosures in both low-frequency and high-frequency approaches, two experimental setups and two numerical models are developed. The use of the composite cover, instead of the metallic one, gives a similar level of SE in the far-field and a higher specific SE (i.e., SE divided by the material density) in the near-field from 1 Hz to 2 kHz. Such quantitative analysis is the first step to designing practical enclosures entirely covered with composite panels to face electromagnetic compatibility (EMC) constraints in embedded systems.