Determining the Shielding Effectiveness of a Partially Filled Functional Cabinet via Radiated Emission Measurements and Shielding Effectiveness Measurements

Abstract

One key technique in electromagnetic compatibility is shielding, which serves to create a barrier between different electromagnetic (EM) zones. The EM shielding of a cabinet determines the radiated emission (RE) outside the enclosure based on the contents inside. This article evaluates the shielding effectiveness (SE) of a commercial off-the-shelf (COTS) 19-in cabinet partially filled with COTS equipment, which represents an actual functional cabinet. RE measurements and SE determinations based on these RE results have been conducted on this enclosure. The different RE results from an open (side panels and door removed) and closed cabinet were used to determine its SE. These RE results, along with the determined SE values, are presented and compared with the SE results of an empty 19-in cabinet. Furthermore, the results are compared with SE results obtained using an intentional source inside the partially filled enclosure. This RE and SE evaluation is applicable to other Faraday cage-like enclosures, such as cars, buses, airplanes, ships, satellites, TEMPEST cabinets, and shielded rooms.