Statistical Anisotropy in Imperfect Electromagnetic Reverberation

Abstract

A probabilistic characterization is performed for a class of field anisotropy coefficients for random electromagnetic fields. Ideal reverberation (isotropy), anisotropic stirring (polarization bias), and incomplete stirring or line-of-sight coupling (direct illumination) are investigated individually. For small degrees of planar anisotropy or bias, trapezoidal distributions are obtained, representing first-order departures from ideal rectangular distributions. Distributions for two definitions of total field anisotropies are found to be less sensitive than those for the individual planar anisotropies. The method and results are useful for calibration and validation of reverberation chambers when field anisotropy requires a separate assessment. Theoretical results are compared to measured data in two chambers.

Reverberation chambers a la carte: An overview of the different mode-stirring techniques

“…Its performance in terms of field isotropy and field homogeneity levels has been detailed in [27], [28], [29], [30].…”

Reverberation chambers through the magnifying glass: an overview and classification of performance indicators

“…Since | | and � � are usually modeled as random variables, then also and are to be considered as random variables with fluctuations according to the stirring process. Probability density functions for these coefficients are reported in [23]. Figure 1 shows the histograms of measured in the RC facility of the Eindhoven University of Technology (TU/e), using a three-axial electric field probe at a single location within the working volume at 1 GHz for 50 stirrer positions.…”

“…These anisotropy coefficients have been extended to represent statistical anisotropy in RCs working in non-ideal, or imperfect conditions [23].…”