Cross-Correlation Analysis of the Cyclostationary Near-Field Unintentional Radiations from the PCB

Cross-correlation analysis of the cyclostationary near-field unintentional radiations from the printed circuit boards (PCB) can be used for the localization of the transmission line paths transferring the deliberately programmed pseudo-random sequences. The unintentional radiations are formed by induced surface currents on the surface of the PCB and can be measured by the near-field magnetic probes scanning along the mesh in the plane parallel to the surface of the PCB. The extracted cyclostationary properties of the radiated emissions were used for the synchronized ensemble averaging of the scanning probe measured signals multiplied by the programmed pseudo-random sequence for estimating the cross-correlation functions. The spatial-time dependence of the obtained cross-correlation predicts the distribution of the average power for the deliberately formed stochastic cyclostationary process transferred over the surface of the PCB. In this paper the ability of the proposed cross-correlation algorithms to identify the spatial and time-frequency characteristics of the stochastic radiated electromagnetic field emitted by multifunctional modern devices was demonstrated.