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—In this paper, all losses in a reverberation chamber (RC) are\ud represented by equivalent absorption cross sections (ACSs), both those due\ud to the power dissipated and those due to the power lost through leakage.\ud This representation enables us to define an absorption cross section of\ud the RC, so that we can easily measure and compare the losses of different\ud natures in an RC directly in terms of ACS. Additionally, this representation\ud of the losses leads to equal measurements of the attendant ACS in relation\ud to two different methods to represent the electromagnetic radiation in an\ud RC suggested by Corona and Hill. As a specific applicative example, an\ud effective method to measure the reflectivity of materials based only on ACS\ud measurements is shown. Finally, its validity will be presented, applying the\ud same principle of the reflectivity measurement to a nested reverberation\ud chamber system

In this letter, the relation between the shielding effectiveness\ud of an electrically large enclosure (SEe) and the shielding\ud effectiveness (SE) of the wall material is derived under uniform\ud and isotropic field conditions. Only enclosures with walls locally\ud planar and reciprocal are considered. It is found that SEe is related\ud to SE by the reflectivity of the enclosure internal walls; thus,\ud it is found that SEe tends to SE with the increasing inner losses,\ud both the wall losses and the load losses. An analytical simulation is\ud shown to support the theory

In this paper, a reexamined estimate of the test fixture validation factor (TFVF) of fixtures for shielding effectiveness (SE) measurements in a reverberation chamber is shown. The fundamental conditions for the applicability of the model shown here are a large aperture between the chambers, whose transmission cross section is well approximated by the geometrical optics, and an isolation between the chambers greater than or equal to 10 dB, as specified in this paper. The model is applicable for both nonmarginal and marginal SE values; but, in the latter case, the requested isolation between the two chambers has to be met with no sample in the aperture. For nonmarginal SE values, the conditions requested for the applicability of the model are practically the same as those requested in the standard IEC 61000-4-21. The model is applicable to SE measurements of gaskets as well. The results show that the TFVF used in the standard procedure IEC 61000-4-21 has to be updated to achieve more accurate measurements of SE in light of the studies conducted on this topic. We give such an update in this study

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