What is a Faraday cage?

A Faraday cage is an enclosure designed to block radio frequency (RF) waves. It is typically made from a conductive material, such as metal, or a mesh of conductive material. When an external electric field or RF wave encounters the Faraday cage, the conductive material redistributes the charges on its surface in a way that cancels out the field's effects inside the enclosure. This makes the interior of the Faraday cage contain the RF energy or radiation, preventing these waves from emitting outward and affecting any electronic equipment or data inside.

Faraday cages block RF waves by leveraging the principle of electromagnetic shielding. When RF waves hit the surface of the conductive material, the electrons in the material move to counteract the wave's electric field. This movement creates an opposing field that neutralizes the incoming RF wave, preventing it from entering the cage. The effectiveness of a Faraday cage in blocking RF waves depends on factors like the conductivity of the material, the thickness of the walls, and the size of any gaps or holes in the structure. This shielding capability makes Faraday cages useful in protecting or shielding RF energy from the device that is covered or contained by the Faraday cage.