Study of shielding properties of cylindrical enclosures illuminated by EMP

Shielding effectiveness(SE) of cylindrical metallic enclosures with apertures illuminated by electromagnetic pulse (EMP) is investigated by the Finite integration time-domain method, combined with the PBA[4]. Three important factors including polarization direction of the incident wave, aperture shape, and aperture array are investigated in detail for their effects on SE. Some valuable conclusions are brought forward. The theoretical analysis and simulation results illustrate that the SE can be improved by selecting appropriate shapes of apertures, ensuring the longer side of apertures is not perpendicular to the polarization direction of the incident wave in the case of that these properties of the incident wave we are known. Finally, keeping the total area unaltered, dividing the single larger aperture into multiple smaller apertures, the SE will be increased.