147 research outputs found
Radiated Immunity Testing of a Device with an External Wire: Repeatibility of Reverberation Chamber Results and Correlation with Anechoic Chamber Results
We present the experimental radiated immunity results of an electronic device with an external wire obtained in reverberation and anechoic chambers. Repeatability and reproducibility of reverberation chamber measurements are investigated by repeating the test in three reverberation chambers with different characteristics. We show how the current state of the art allows a statistical control of RC measurement repeatability within an industrial installation, and that a statistical correlation with AC results frequency by frequency is possible in particular cases relevant to automotive application
Universal behaviour of a wave chaos based electromagnetic reverberation chamber
In this article, we present a numerical investigation of three-dimensional
electromagnetic Sinai-like cavities. We computed around 600 eigenmodes for two
different geometries: a parallelepipedic cavity with one half- sphere on one
wall and a parallelepipedic cavity with one half-sphere and two spherical caps
on three adjacent walls. We show that the statistical requirements of a well
operating reverberation chamber are better satisfied in the more complex
geometry without a mechanical mode-stirrer/tuner. This is to the fact that our
proposed cavities exhibit spatial and spectral statistical behaviours very
close to those predicted by random matrix theory. More specifically, we show
that in the range of frequency corresponding to the first few hundred modes,
the suppression of non-generic modes (regarding their spatial statistics) can
be achieved by reducing drastically the amount of parallel walls. Finally, we
compare the influence of losses on the statistical complex response of the
field inside a parallelepipedic and a chaotic cavity. We demonstrate that, in a
chaotic cavity without any stirring process, the low frequency limit of a well
operating reverberation chamber can be significantly reduced under the usual
values obtained in mode-stirred reverberation chambers
Reverberation chambers a la carte: An overview of the different mode-stirring techniques
Reverberation chambers (RC), a name inspired in room acoustics, are also known in literature as reverberating, reverb, mode-stirred or mode-tuned chambers. In their basic form, they consist of a shielded metallic enclosure, forming a cavity resonator, together with some mode-stirring mechanism. The main goal of such stirring mechanism is to generate an amplitude-varying electromagnetic field that is ideally statistically uniform
Probability Distribution of the Quality Factor of a Mode-Stirred Reverberation Chamber
We derive a probability distribution, confidence intervals and statistics of
the quality (Q) factor of an arbitrarily shaped mode-stirred reverberation
chamber, based on ensemble distributions of the idealized random cavity field
with assumed perfect stir efficiency. It is shown that Q exhibits a
Fisher-Snedecor F-distribution whose degrees of freedom are governed by the
number of simultaneously excited cavity modes per stir state. The most probable
value of Q is between a fraction 2/9 and 1 of its mean value, and between a
fraction 4/9 and 1 of its asymptotic (composite Q) value. The arithmetic mean
value is found to always exceed the values of all other theoretical metrics for
centrality of Q. For a rectangular cavity, we retrieve the known asymptotic Q
in the limit of highly overmoded regime.Comment: accepted for publication in IEEE Trans. Electromagn. Compat., 201
- âŠ