Phaseless near-field measurements

Near field techniques allow to estimate a 3D map of the electromagnetic emission of an equipment exploiting the knowledge of the field on a surface. However, standard near field techniques are based on the measurement of the complex (amplitude and phase) field, while many measurement devices exploited in the framework of electromagnetic compatibility, like the spectrum analyzer, are scalar receivers. A general procedure for reconstructing the phase from only amplitude measurements, is described in this paper so that a 3D map of the electromagnetic emission from data collected by spectrum analyzers is made possible. The validity of the approach is shown by a numerical example involving a phase retrieval problem