Parameters characterizing the effectiveness of electromagnetic shielding
Electromagnetic shielding

The effectiveness of electromagnetic shielding is assessed by measurable quantities, based on two physical concepts [9] :

• the attenuation of a shield, expressed in dB ;

• the homogeneous transfer impedance with a linear parameter expressed in Ω/m.

As the following examples show, the choice of definition depends on the type and area of application of the shielding.

• Consider a metal enclosure, such as a Faraday cage, exposed to an electromagnetic field.

• Field sensors, located where the enclosure will be installed, measure the electrical and magnetic components, noted respectively