On the Adequacy of the Far-Field Conditions for Pulsed Radiated EM Fields

The far-field region's bound is investigated in case of the pulsed electromagnetic field radiation. The value predicted by means of “standard,” time-harmonic considerations is compared with that following from the ratio between the maximum value of the time-domain, near- and far-field magnetic field strength constituents. The adequacy of these criteria is analyzed in the case of a loop-to-loop transfer scenario. The obtained results are of relevance for close-range, wireless digital transfers and provide a safety margin for ensuring the adequacy of the “standard” far-field region's limit in ultrawideband links.