Doppler Spectrum Analysis for the Prediction of Rotating Mode Stirrer Performances in Reverberation Chamber

This paper presents how the Doppler spectrum (DS) induced by rotating mode stirrers can be used in order to assess and optimize their performances when used in reverberation chambers. Indeed, a rotating mode stirrer acts as a diffracting structure whose performances are related to the DS spread. The performances of such stirrers are shown to be predictable by analyzing their DS in free space from numerical simulations using full-wave solvers with reasonable computation times. This allows the geometry of a future mode stirrer to be optimized before being built and installed in the chamber.properties of the object. A better diffracting structure is proved to increase the number of uncorrelated samples obtained during the rotation of the object. The performance comparison of different canonical MS has shown the influence of the SV of the object during its rotation but also the diffracting effect of its projecting edges and corners. Indeed, an increase of the length edges and the presence of corners is shown to increase the performances of the object as anMS. The performances of a rotating MS are shown to be predictable from numerical simulations performed in free space using full-wave solvers. The RC users can therefore first optimize the MS geometry numerically in a reasonable amount of time and in a second step build the optimized one in order to install it in their RC. In reason of the stability of frms d with the frequency, the numerical results obtained in free space prove that such optimization process can be performedperformance comparison of different canonical MS has shown the influence of the SV of the object during its rotation but also the diffracting effect of its projecting edges and corners. Indeed, an increase of the length edges and the presence of corners is shown to increase the performances of the object as anMS. The performances of a rotating MS are shown to be predictable from numerical simulations performed in free space using full-wave solvers. The RC users can therefore first optimize the MS geometry numerically in a reasonable amount of time and in a second step build the optimized one in order to install it in their RC. In reason of the stability of frms d with the frequency, the numerical results obtained in free space prove that such optimization process can be performed