RFI shielded windows: Understanding the tradeoffs associated with the selection of specific materials against anticipated performance simplifies shielded window selection

摘要

ONE OF THE MANY REQUIREMENTS FOR THE SHIELDING-integrity of equipment enclosures is the need for large-area openings for access to electronics, ventilation, and displays. The displays may be panel meters, digital displays, oscilloscopes, status monitors, mechanical indicators, or other readouts. The most critical displays to shield against electronic noise are large area, high resolution monitors (CRTs). Shielding of these large apertures is generally more difficult than that encountered for cover plates, doors, ventilation panels, and small apertures, such as connectors, switches and other controls in which most of the opening is covered by a continuous homogeneous conductive (metal) plate. Therefore, when working with window designs that do not have a continuous conductive cover, consideration must be given to vital issues: namely, shielding as related to relative apertures and viewing quality as related to optical characteristics of shielding screens and supporting substrates. These two factors are inter-related and need to be treated as a combined problem.