Statistics of the Reradiated Spectrum from Multiple Nonlinear Devices in a Reverberation Chamber

The statistical distributions of the reradiated spectrum from an ensemble of nonlinear devices subjected to radio-frequency interference measured in a reverberation chamber are investigated. This phenomenon can be used to probe the interaction between threatening radio-frequency energy and digital hardware. Previously, a statistical model was developed to explain the statistics of the measured spectrum from a single nonlinear element. Here, the model is extended to the more realistic situation with multiple reradiating sources. It is observed in the measurement results that two parameters, the power level of the interference and the spatial distribution of the reradiating sources, have effects on the statistical distribution. It is shown that the Monte Carlo simulations based on the statistical models can properly reconstruct the measured statistical distributions. Understanding the signature of the onset of hard nonlinearity in the observed spectrum may lead to the development of an immunity diagnostic tool that does not depend on monitoring the functional behavior of the equipment-under-test.