Theory of Electromagnetic Shielding with Applications to MIL-STD-285, IEEE-299, and EMP Simulation

摘要

A shielding theory based on Impedance Boundary Conditions is developed and used to obtain formal expressions for the fields transmitted to the interior of a generalized metallic structure from an arbitrary, external, time harmonic, electromagnetic source. The structure is an assemblage of planar sheets that may be penetrated by a finite number of narrow rectangular slots. It includes both a single sheet (continuous or slotted) and a rectangular enclosure (continuous or slotted) as special cases. Explicit expressions are then derived for the transmitted electric and magnetic fields at points on the inside surfaces of plane sheets (continuous and slotted) and rectangular enclosures (continuous and slotted) when these structures are exposed to fields from elementary electric and magnetic dipoles and small rectangular loop antennas. These expressions are then used to obtain the shielding effectiveness of sheets and enclosures.