Generalized Extreme-Value Distributions of Power Near a Boundary Inside Electromagnetic Reverberation Chambers

This paper presents results of an experimental investigation regarding the statistical distribution of the maximum field and analysis of statistical field inhomogeneities near a cavity wall inside a reverberation chamber. Measurements were performed for both undermoded and overmoded regimes. Departures from ideal isotropic random field behavior at relatively low frequencies were measured by placing a receiving antenna close to one cavity wall. The coexistence of field heterogeneity and anisotropy has been confirmed, together with departures from the ideal statistical distributions of field and energy. Empirical distributions of the maximum value were derived for hybrid (i.e., combined mechanical, frequency, and spatial) mode stirring. The maximum-value distribution is found to be of Fréchet type in undermoded regime and converges to a reverse Weibull distribution in highly overmoded operation, with a transit across the Gumbel distribution when the operation is weakly overmoded. Results exhibit good agreement with previous theoretical and numerical findings.