Numerical and Experimental Validation of Near-Field Power Density Reconstruction from Radiative Field Measurements

RF EMF compliance from millimeter-wave wireless devices intended to be used in close proximity of the head or body is determined based on assessment of the incident power density. A previous publication has introduced a new approach to assess this quantity, based on spherical measurements at larger distances from the device under test, combined with equivalent source reconstruction. This paper proposes a more extensive validation of this technique based on simulations and measurements of reference antennas, as defined in the standard IEC/IEEE 63195-1. An agreement better than 15% is obtained in a majority of cases between reconstructed and reference values, establishing the suitability of the approach for compliance evaluations of wireless devices. Various error contributors are also discussed, and a justification is provided that the loss of reactive field information due to probing at larger distances has a limited impact on accuracy, when power density is averaged over a 1 to 4 cm
²
surface.