An Estimate of Plane Wave Leakage Through a Rectangular Aperture

The prediction of leakage power through a metallic aperture is important for the design of EMC chasses and enclosures in terms of shielding effectiveness. Based on the analytical technique and model developed by Robinson et al, EM leakage through a rectangular aperture on a rectangular waveguide and through a rectangular aperture on a planar metal sheet was analyzed in this study. The analysis results were then checked with numerical technique and were found to be in reasonable agreement. This analysis technique can also be applied to the prediction of EM leakage through an aperture on shielding enclosures having other shapes, provided that the enclosure size is sufficiently larger than the aperture. The effect of aperture size and geometry on the amount of power leakage has been clearly demonstrated in this study.