Influence of grounding conditions on SE of shielded room in LEMP environment

In order to analyze the influence of grounding conditions on the shielding effectiveness (SE) of shielded room, numerical simulation is done by applying parallel Finite-Difference Time-Domain (FDTD) method on the coupling problems between shielded room and lightning electromagnetic pulse (LEMP) environments. Inner coupled electromagnetic (EM) fields are calculated when the shielded room is with different grounding locations and schemes. The results indicate: (1) the farther the distance between the grounding location and the aperture, the better the SE of shielded room, the nearer the worse. (2) The SE is related to the different grounding schemes (single-point grounding and multipoint grounding). For a better SE to LEMP, shielded room should use single-point grounding.