I. Introduction
The measurement of the shielding effectiveness (SE) of shielded enclosures has a long history in the electromagnetic compatibility field. It is currently based on different methods and standards according to their size and the frequency range of measurement. At high frequencies, i.e., frequencies for which the enclosure size is in the order of magnitude of the wavelength, such measurements are tricky due to intrinsic variations of fields according to positions of antennas(s) or probe(s) both within and outside of the enclosure under test (EUT). Moreover, SE depends on the enclosure contents, specifically in the resonance regime of the EUT. These factors have triggered different works over the past 20 years, aiming at improving measurement procedures along with some changes in the SE definition.