Abstract
International radio frequency (RF) electromagnetic field (EMF) exposure assessment standards and regulatory bodies have developed methods and specified requirements to assess the actual maximum RF EMF exposure from radio base stations enabling massive multiple-input multiple-output (MIMO) and beamforming. Such techniques are based on the applications of power reduction factors (PRFs), which lead to more realistic, albeit conservative, exposure assessments. In this study, the actual maximum EMF exposure and the corresponding PRFs are computed for a millimeter-wave radio base station array antenna. The computed incident power densities based on near-field and far-field approaches are derived using a Monte Carlo analysis. The results show that the actual maximum exposure is well below the theoretical maximum, and the PRFs similar to those applicable for massive MIMO radio base stations operating below 6 GHz are also applicable for millimeter-wave frequencies. Despite the very low power levels that currently characterize millimeter-wave radio base stations, using the far-field approach can also guarantee the conservativeness of the PRFs used to assess the actual maximum exposure close to the antenna.
Highlights
To meet the increasing demands on mobile traffic data, the fifth-generation cellular communication technology (5G) exploits the frequency spectrum above 24 GHz, which provides much wider and contiguous bands compared with the crowded and fragmented spectrum below 6 GHz
Good converges to the power reduction factors (PRFs) obtained from the far-field approach can be observed above 0.5 m, and above 1 m, the difference in PRFs obtained from the near-field and the far-field approaches is negligible
The PRF values are derived for the specific array antenna configuration used in this study
Summary
To meet the increasing demands on mobile traffic data, the fifth-generation cellular communication technology (5G) exploits the frequency spectrum above 24 GHz, which provides much wider and contiguous bands compared with the crowded and fragmented spectrum below 6 GHz. Before radio base stations (RBSs) are placed on the market, manufacturers normally need to conduct electromagnetic field (EMF) exposure assessments to determine the so-called compliance boundaries or exclusion zones. The EMF exposure from an RBS is below the relevant EMF exposure limits, for example, those provided in the international EMF exposure guidelines. The most widely adopted EMF exposure guidelines are provided by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) [2, 3]. As the previous generations of mobile communication technologies, 5G equipment, including mmW RBSs, must comply with the same EMF exposure guidelines
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
