Propagation methods for stochastic field emissions and source reconstruction

Stochastic electromagnetic field propagation— measurement and modelling

“…When detected by probes, EM fields are perturbed by the probe structure itself. As explained in [ 50 ], a more subtle effect in NFS concerns the coupling of probes with the surface current density distribution flowing at the source surface. A correction factor can be evaluated by either dedicated experiments or simulations, which can be used to predict the transfer impedance between the field incident on the probe and the voltage read from its port [ 52 ].…”

“…For statistical sources, it is therefore natural to consider correcting entries of the CT involving the correction factor. Nevertheless, it is shown through plane-wave expansion [ 53 ] and operator theory [ 50 ] that the propagation of probe voltage–voltage CFs is equivalent to the propagation of field–field CFs. A proposal for standardization of near-field measurement of stochastic EM fields led by the European COST Action 1407 has been initiated in [ 54 ].…”

“…In this paper, we discuss extensions of this formalism to include vector fields, which naturally leads to a Wigner tensor (WT). In previous work, predictions based on this WF approach have been verified in both the far field [29] and the near field [33]. NFS for field correlations in stochastic EM fields requires at least two field probes and has been addressed in [34][35][36][37].…”

“…Another approach to modelling the propagation of field CFs is obtained by using a representation of the field in the combined space of position and wavevectors. The process is carried out through a representation known as the WF method [15], from which a raytracing-based approximation of the propagated CF can be derived [28,29]. Furthermore, in the propagation of CFs calculated from NFS of noisy fields, the connection between CFs and phasespace distributions to extract explicit directional information from the measurement process can be exploited.…”

“…Representing EM fields in phase space goes beyond Heaviside's insight and leads to new insight in the form of finding the universal behaviour of completely randomized fields and including partial positional and directional information for geometries that are only partially irregular [31]. So far, we have treated the propagation of CFs of scalar field components in free space [29] and confined space [32]. In this paper, we discuss extensions of this formalism to include vector fields, which naturally leads to a Wigner tensor (WT).…”