Measurement of shielding in electrically large metallic enclosures

摘要: The measurement techniques employed to obtain the shielding effectiveness (SE) of enclosures using current version IEEE 299.1 only apply side dimension greater than 0.1m, and are also lacking in a full analysis field distributions within enclosure. work presented here uses draft standard as base investigates different methods obtaining SE, well looking at making more applicable physically small electrically large enclosures, hoping inform future versions standards for enclosures. The first part this thesis use comb generator source an enclosure under test (EUT), which provides statistically uniform electric inside EUT when combined with mechanical stirrer. used is equivalent size 19 inch rack unit many equipment rigs; therefore investigations it relevance real world. It becomes apparent that important be sure statistical uniformity achieved chamber. chamber University York compared Ancona, Italy. Meanwhile, found presence direct path or unstirred component distribution can change measured SE. A study aperture dominated EUTs reveals possible indication SE Q−factor. This method has advantage applied have low apertures, case some enclosures. Continuing development into testing outside scope 299:1997, shown represented by larger considering 299.1.