Universal Statistical Tradeoffs for Shielding Effectiveness Evaluation of Electrically Large Enclosures in Reverberation Chambers

Abstract

Shielding effectiveness (SE) evaluation of electrically large enclosures within reverberation chambers (RCs) is standardized procedure for electromagnetic compatibility (EMC) applications. In this work the potential relationship between SE and electromagnetic resonances have been investigated with respect to the ambiguity in definition of SE for the international standards, e.g., IEC 61000-4-21 or IEEE Std 299.1. From a statistical point of view, we derive the expansions of SE defined by the ratio of the maxima and the averages respectively. To evaluate SE more prudently as well as to obtain a much smaller uncertainty, we can make the tradeoffs for SE, which should be defined as the ratio of the averages for the overmoded frequency, and the ratio of the maxima for the undermoded using a common criterion aimed to discriminate the electromagnetic field behavior between the undermoded and the overmoded, and also verify the corresponding results by numerical simulations and measurement performed in RC.