Numerical evaluation of Near-Field to Far-Field transformation robustness for EMC

Near-Field (NF) to Far-Field (FF) transformation techniques are widely used for antenna radiation problems. To perform a NF to FF or a NF to NF transformation for EMC applications, the large frequency range, and a weak signals will require data in the reactive near field. In principle, the transformation can be performed if all sources are confined in the scanned area using Huygens´ Principle, which requires knowledge of the exact phase and magnitude data of measured fields. In reality, this cannot be achieved, due to uncertainties in the field probe measurements, presence of active and passive cables and limited scan areas. Thus, it is attempted to perform a transformation based on an incomplete and uncertain data set. Results of a numerical simulation tool usage for NF to FF transformation based on NF-Scanning system measured data are demonstrated.