Improving Shielding Effectiveness of Enclosure with Apertures using Absorbers

Generally, metallic enclosures have been used in order to electromagnetically shield and mechanically protect the interior equipment and systems from the high power electromagnetics. But in the practical situations, the apertures or slots of various forms are essential parts of the shielding enclosure for air ventilation, door for operator, power and signal cabling and so on. The performance of shielding enclosures for protecting critical equipment and system against high power electromagnetic field is compromised by those inevitable apertures on enclosure. To minimize the effect on shielding properties by apertures, the shielding enclosures with apertures should be designed based on the thorough analysis about the electromagnetic coupling mechanism through apertures. In this paper, the shielding properties of the metallic enclosure with aperture are studied with 3D full wave simulation. A method for improving the shielding effectiveness of enclosure with apertures is proposed and is verified by numerical analysis.