Universal behaviour of a wave chaos based electromagnetic reverberation chamber

TL;DR

This study numerically investigates electromagnetic Sinai-like cavities, demonstrating that complex geometries naturally exhibit statistical behaviors akin to random matrix theory, potentially replacing mechanical stirrers in reverberation chambers.

Contribution

The paper introduces complex cavity geometries that inherently satisfy statistical requirements for reverberation chambers, reducing the need for mechanical mode-stirrers and enhancing performance.

Findings

Complex geometries improve statistical behavior without stirrers

Suppression of non-generic modes by reducing parallel walls

Chaotic cavities lower the frequency limit for effective operation

Abstract

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.