Electromagnetic shielding

The goal of electromagnetic (EM) shielding is to protect electrical and electronic components and assemblies from external EM fields or to prevent that EM fields produced by apparatus and systems may be source of interferences or malfunctioning; in fact, such EM fields can interfere with the electronic devices causing damages and failures in their operation. Clearly, the level of the required shielding is not unique and is dictated by the level of EM field that ruins the performance of each device. In addition, EM shielding often is required to limit EM radiation according to various standards. Limitations and protections usually are obtained by means of a three-dimensional structure, the so-called shield; the shields thus are used to inhibit propagation of EM fields from one region of space to another one. In particular, they can enclose the source of EM interference confining the field in a finite region inside the shield (and thus protecting the external world), or they can enclose the apparatus that needs protection keeping the EM field outside their interior region.