Conference Agenda

In this contribution, physical bounds on the time-domain (TD) response of a linear time-invariant (LTI) system are briefly discussed regarding selected applications in electromagnetic compatibility (EMC). An illustrative example describing a worst-case bound on the plane-wave shielding performance of a planar conductive layer is presented.

This paper presents a comprehensive methodology for determining the shielding effectiveness of planar dielectric materials at microwave frequencies. The approach integrates the extraction of high-frequency electromagnetic parameters (permittivity and permeability) using a rectangular waveguide technique with theoretical SE calculations, direct shielding effectiveness measurements via a modified ASTM D4935-18 coaxial sample holder, and finite element method simulations. Two distinct planar dielectric composite materials are characterized. Their complex permittivity and permeability, measured over the frequency range of 8.2 GHz to 12.4 GHz, are used to predict their shielding effectiveness theoretically. These predictions are subsequently validated against experimental measurements conducted from 1.5 GHz to 10 GHz using the coaxial sample holder, as well as against full-wave electromagnetic simulations. The results demonstrate strong concordance across the theoretical, experimental, and simulation approaches, validating the proposed framework for shielding effectiveness assessment and highlighting the impact of material dielectric losses on shielding performance. This work provides a robust procedure for characterizing and predicting the performance of thin and flexible dielectric materials.

Shielding Effectiveness (SE) measurement techniques for shielded enclosures with apertures and shielding covers have been a topic of research for quite some time now. Minimizing the measurement time was achieved by transitioning from anechoic chambers to reverberation chambers. The nested reverberation chamber technique was then introduced, which has been well established over the years for doing SE measurements but requires multiple antennas and stirrers within the outer and inner chambers. Recent studies have sought to minimize the use of multiple antennas and stirrers within the inner chamber to measure the shielding effectiveness of physically small but electrically large enclosures of dimensions comparable to λ/4 , as having sensors inside such enclosures is often difficult in more realistic scenarios at frequencies in the GHz range. This paper builds upon this line of thought and extends the method of estimating shielding effectiveness for electrically large enclosures to include material samples such as metal sheets with holes, ventilation ducts used in Faraday Cages and other such samples which are "imperfect" shields but are commonly employed in realistic scenarios.

Transfer impedance (Zt) is a key parameter for evaluating coaxial and data cable shielding effectiveness (SE). Standard measurement methods, such as injection and triaxial methods, are widely used. However, this paper focuses on an experimental approach based on the principles described in two scientific studies [1], [2], which have not been described in detail outside the sources cited. The proposed method uses direct signal injection through a precisely dimensioned transmission channel and analyzes the phase relationship of two S-parameters - the reflection coefficient and forward gain. This approach allows for efficient and reliable Zt determination without modifying the tested cables. The method was extended to include the possibility of measuring data cables in this study, thus expanding its application area. The experiment included measurements of different types and lengths of coaxial cables, while a selected type was tested for data cables. The results confirm that the presented method provides consistent and reproducible Zt values with the potential for further development for a broader range of cable structures.