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 [1-4]. 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.

Short-wavelength Reverberant Wave Systems for Enhanced Reservoir Computing

“…into analog waveforms by an AWG (arbitrary waveform generator) and stored for both the training and testing time-series data sets. After appropriate time scaling, the input signal is then amplified and injected into a wave chaotic microwave cavity [25][26][27][28][29][30].…”

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 [ 39 , 40 ]. A hybrid PWB/RCM method has recently been proposed in [ 41 ].…”

“…This treatment mirrors the diagonal approximation adopted to obtain the DEA flow equations, where the phase difference between waves disappear under averaging. Interference induced fluctuations between waves can be predicted separately by statistical methods to give a probability distribution around the average energy provided by DEA/PWB discussed in this paper (see [ 41 ] for an example involving coupled cavities). Furthermore, it has been shown in [ 54 ] that the energy variance can be estimated via the autocorrelation of DEA densities.…”

Eigenfunction and eigenmode-spacing statistics in chaotic photonic crystal graphs

“…Wave-chaotic phenomena have been studied in various systems, ranging from 1D graphs [1][2][3][4][5], 2D billiards [6][7][8][9][10][11][12] to 3D enclosures [13][14][15][16][17][18]. The statistical properties of many system quantities, such as the closed system eigenvalues and the open system scattering/impedance matrices, exhibit universal characteristics, which only depend on general symmetries (e.g., time-reversal, symplectic) and the degree of system loss.…”

“…The statistical properties of many system quantities, such as the closed system eigenvalues and the open system scattering/impedance matrices, exhibit universal characteristics, which only depend on general symmetries (e.g., time-reversal, symplectic) and the degree of system loss. The Random Coupling Model (RCM) has found great success in characterizing the statistical properties of a variety of experimental systems by removing the non-universal effects induced by port coupling and short-orbit effects [9,13,14,16,17,[19][20][21][22][23][24]. Chaotic microwave graphs support complex scattering phenomena despite their relatively simple structure, and allow for various useful circuit components (such as phase shifters and attenuators) to be incorporated into the structure [3][4][5].…”