A Comparative Study of In Situ Methodologies for Assessment of RF EMF Exposure from a 5G FR2 Base Station

In this work, in situ measurements of the radio frequency electromagnetic field (RF-EMF) exposure have been conducted for an indoor massive MIMO 5G base station (BS) operating at 26-28 GHz. Measurements were performed at six different positions (at distances between 9.94 and 14.32 m from the BS), of which four were in line-of-sight (LOS) and two were in non-line-of-sight (NLOS). A comparison was performed between the measurements conducted with an omnidirectional probe and with a horn antenna, for scenarios with and without a user equipment (UE) used to actively create an antenna traffic beam from the BS towards the measurement location. A maximum exposure of 171.9 mW/m
²
was measured at a distance of 9.94 m from the BS. This is below 2% of the ICNIRP reference level [1]. Moreover, the feasibility to measure the power per resource element of the Synchronization Signal Block - which can be used to extrapolate the maximum exposure level - with a conventional spectrum analyzer was shown by comparison with a network decoder.