Performance and Analysis of a Reverberating Enclosure with Variable Geometry

Probability Distribution of the Quality Factor of a Mode-Stirred Reverberation Chamber

“…Quasistationary mode stirring may results in purely local uniform temporal averaging of the fields across an interval of stir states [0, T ] varying with time. This averaging does obviously not affect the spatial averagings of U (r|τ ) and P d (r S |τ ), yielding again (11) and (12). Ensemble averaging of U (τ ) and P d (τ ) across [0, T ] does not affect U (τ ) and P d (τ )|U (τ ) , whereas both σ 2 U(τ ) and σ 2 P d (τ )|U(τ ) scale by the same variance function γ T in quasi-stationary conditions [22].…”

Mode-Stirred Chamber Calibration Factor, Relaxation Time, and Scaling Laws

“…be worthwhile to examine it analytically in further work from a frequency-domain viewpoint. The critical frequency Fmin for mode overlap to occur may be evaluated by manipulation of (20) [5] and used by other workers [6]. An One would attribute (27) to a matched isotropic antenna with a 3-dB polarization loss.…”

Estimating the expected power density in a reverberating cavity through space averaging

“…This last assumption is actually non physical, ask p ·ξ p = 0, ∀ p ∈ [1, N], although it is not expected to have a major impact on the statistical properties derived in Section III. As reported in several studies [1], [7], the directions of propagation {k p } and the polarizations {ξ p } can be regarded, for an overmoded cavity, as uniformly distributed over a 4π steradian angular region. Conversely, no assumption will be required for the modal weights {γ p }.…”

“…Reverberation chambers are often regarded as environments where statistical field distributions are excited [1] to be used, e.g., for radiated immunity tests in EMC problems. Other applications range from total-radiated-power measurements [2], to the assessment of the electric properties of materials, in particular losses [3].…”

“…This is usually done by applying in a straightforward way the definition of ensemble average, by generating an ideally large set of statistically independent random samples. The most common way of doing so is to introduce a random variation in the propagation of waves within the chamber, e.g., by modifying the boundary conditions over a region of space [1] (mechanical stirrers), or the propagationrelated phase shift [4] (frequency stirring). Such approach is unfortunately impaired by the limited number of independent samples that can be gathered, so that statistical uncertainty may be inappropriately high [5].…”