TD-shielding effectiveness of enclosures in presence of ESD

Shielding of electromagnetic transient fields requires a correct vision of the coupling mechanism and of fundamental aspects of victim functionality and susceptibility. Suitable parameters for the measure of the shielding efficiency are necessary in case of typical transient fields like ESD and classical the information provided by the shielding effectiveness as defined in IEEE-Std.299 may be not sufficient. An attempt of introducing new definitions for time domain parameters is presented. ESD has been chosen as example of typical time domain threat.