Efficient Statistical Model for Predicting Electromagnetic Wave Distribution in Coupled Enclosures

Abstract

The Random Coupling Model (RCM) has been successfully applied to predicting the statistics of currents and voltages at ports in complex electromagnetic (EM) enclosures operating in the short wavelength limit [1][2][3][4]. Recent studies have extended the RCM to systems of multi-mode aperturecoupled enclosures. However, as the size (as measured in wavelengths) of a coupling aperture grows, the coupling matrix used in the RCM increases as well, and the computation becomes more complex and time consuming. A simple Power Balance Model (PWB) can provide fast predictions for the averaged power density of waves inside electrically-large systems for a wide range of cavity and coupling scenarios. However, the important interference induced fluctuations of the wave field retained in the RCM are absent in PWB. Here we aim to combine the best aspects of each model to create a hybrid treatment and study the EM fields in coupled enclosure systems. The proposed hybrid approach provides both mean and fluctuation information of the EM fields without the full computational complexity of coupled-cavity RCM. We compare the hybrid model predictions with experiments on linear cascades of over-moded cavities. We find good agreement over a set of different loss parameters and for different coupling strengths between cavities. The range of validity and applicability of the hybrid method are tested and discussed.

Wireless Power Distributions in Multi-Cavity Systems at High Frequencies

“…Alternatively, the full probability density of the fluctuations in coupled cavities can be obtained from the Random Coupling Model (RCM), where the cavity fluctuations are produced using random matrix ensembles [38,39]. A hybrid PWB/RCM method has recently been proposed in [40].…”