Why a Reverberation Chamber Works at Low Modal Overlap

Abstract

International audienceThe physical parameter well adapted to assess the degree of overmodedness of a reverberation chamber (RC) is the number $M_M$ of modes overlapping in a mode bandwidth. The lowest usable frequency of an RC often corresponds to a low modal overlap of one or two modes. Notwithstanding, in spite of this poor number of modes the RC still works. We show, using Monte Carlo simulation, that the number of modes must, in fact, not be restrained to $M_M$ and that the number of modes contributing to the field statistics can be, even at low modal overlap, somewhat larger than expected

Probability Distribution of the Coherence Bandwidth of a Reverberation Chamber

“…Thus, the formal identification (4) defines the random excitation width at half height (average −3 dB width) through an effective resonance modeled on a single equivalent Lorentzian in overmoded regime. The model is expected to remain applicable at relatively low frequencies as well, where static modal overlap is limited but chamber performance is still governed by the effectiveness of the dynamic stir process [15], [16].…”

Variability and Confidence Intervals of the Power Measured in a Reverberation Chamber

“…The approach describing the modal parameters as independent random variables has been presented more recently in [7] and used in [5] and [8]. The variability of the electric-energy density has been derived in the aforementioned works by introducing, for the latter, the statistical bandwidth concept.…”

Goodness-of-Fit Tests in Reverberation Chambers: Is Sample Independence Necessary?

“…Ideally, the excitation of a minimum number of modes [1] allows the field to approximatively follow a Gaussian law.…”