On the prediction of the average absorbing cross section of materials from coherence bandwidth measurements in reverberation chamber

The average absorbing cross section is obtained from S₁₁ parameters measured in reverberation chamber by using a single antenna. This method uses the coherence bandwidth estimated from the complex correlation function of the empty and loaded chamber. The load consists of parallelepiped absorbers whose dimensions and electrical parameters are known. An approximate model is developed to calculate the average absorbing cross section. The model uses the average projected surface and includes a correction associated with the absorber edges effect. Comparisons between simulations and measurements are done. It results that the average absorbing cross section can be a priori approximated. This method enables to predict how the wireless channel can change (e.g., if it will be affected or not by intersymbol interference or attenuation) in the presence/absence of parallelepiped absorbers.