A mechanical mode-stirred reverberation chamber with chaotic geometry

TL;DR

This paper investigates how chaotic geometries in reverberation chambers enhance their performance by destroying regular modes and increasing the number of independent realizations, using numerical simulations and wave-chaos concepts.

Contribution

It introduces chaotic geometries into reverberation chambers to improve their performance, demonstrating the benefits through numerical simulations and analysis.

Findings

Chaotic geometries increase the number of independent cavity realizations.

Wave chaos reduces regular modes and improves chamber performance.

Numerical simulations confirm enhanced performance with chaotic shapes.

Abstract

A previous research on multivariate approach to the calculation of reverberation chamber correlation matrices is used to calculate the number of independent positions in a mode-stirred reverberation chamber. Anomalies and counterintuitive behavior are observed in terms of number of correlated matrix elements with respect to increasing frequency. This is ascribed to the regular geometry forming the baseline cavity (screened room) of a reverberation chamber, responsible for localizing energy and preserving regular modes (bouncing ball modes). Smooth wall deformations are introduced in order to create underlying Lyapunov instability of rays and then destroy survived regular modes. Numerical full-wave simulations are performed for a reverberation chamber with corner hemispheres and (off-)center wall spherical caps. Field sampling is performed by moving a mechanical carousel stirrer. It is found that wave-chaos inspired baseline geometries improve chamber performances in terms of lowest usable frequencies and number of independent cavity realizations of mechanical stirrers.