Named after the English physicist Michael Faraday, the Faraday cage is a cavity surrounded by an electrically conductive material.
Such conductive shielding prevents electric fields from entering the cavity and functionally impairing the electronic components or assemblies contained therein. A metal box, enclosure, rack or room that is RF-tightly surrounded by a metallic shield constitutes a Faraday cage. Faraday cages are often constructed of Mu metal because this metal has a particularly high permeability.
Electric fields hitting a faraday cage are conducted around the hollow body in the shielding and do not enter it. Inside the faraday cage, there are no electric fields penetrating from the outside.
In practice, lightning protection systems and other technical equipment against lightning protection, as well as rooms for interference radiation measurements or equipment shielding are designed as faraday cages.