Shielding effectiveness and electromagnetic protection

Typical shielding effectiveness measurements and their relation to electromagnetic protection are reported. These measurements, which are based on the insertion loss when the shield is inserted between two antennas, contain the properties of the antennas and receivers inextricably commingled with the properties of the shield. For the assessment of electromagnetic protection, the shield´s ability to limit the interaction of any arbitrary external source with an arbitrary internal circuit is found to be important. The assessment of protection cannot, in general, be obtained from insertion loss data