An efficient shielding effectiveness analysis of rectangular box perforated with numerous apertures by transmission line model

The shielding effectiveness of a metallic shield perforated with numerous apertures of various shapes is evaluated in this paper. Here an appropriate admittance which takes the mutual coupling between the apertures into account is considered to represent the array of apertures. This method is applicable to an array of square, circular and rectangular holes of rectangle and square configurations. Results from the simulations demonstrate that: more coupling energy is obtained when the frequency is below the frequency of resonance and shielding and enclosure are closer; when the resonance is in between the aperture and enclosure, it causes in the metal shield a reduced shielding effectiveness; lower frequencies display better shielding than higher frequencies; the effectiveness of shielding of a single hole is worse than of a multi-hole for identical areas. This method is extremely efficient and easy to implement compared to numerical techniques.