Comparative study of the effects of dosimetric E-field sensor size on the detected field intensity, at 5.2 GHz and 5.8 GHz

Numerical and experimental characterizations of the dosimetric E-field probe sensor size has been performed at 5.2 GHz and 5.8 GHz. Also investigated is the, 2.8mm and 4.9mm tip-diameter probes which have been designed and validated against international regulations' and standards. Numerical characterizations show that smaller probe-sensors have lower sensitivity than longer probe-sensors. Lab measurement results show that both of the fabricated probes (3mm and 4.9mm diameter) yield SAR values in line with the FDTD (finite-difference-time-domain) derived target SAR values within +/-5%. When the probe is in immediate proximity of the phantom boundary, probe positioning uncertainty becomes a major factor. Probe positioning uncertainty, as well as boundary effect, can be reduced by keeping this distance to at least 0.6mm from the probe tip. Since the difference in SAR between the two probes is less than 13%, we conclude that the 4.9mm and 2.8mm probes are both equally suitable to be used for dosimetric assessment in the 5.2–5.8 GHz frequency range.