Investigation of Power Levels Related to Different EMF Exposure Metrics at 6 GHz

Abstract

Overview

New wireless technologies greatly utilize the spectrum around 6 GHz, such as Wi-Fi®6E, which operates both below and above this frequency. This range poses significant challenges for electromagnetic field (EMF) exposure assessments.

Findings

• The shift from the Specific Absorption Rate (SAR) to Absorbed Power Density (APD) at 6 GHz changes the measurement metric, and due to limitations, Incident Power Density (IPD) is often used instead.
• This study explores the discrepancies in maximum allowed output power at the transitional frequency of 6 GHz, utilizing a dipole antenna and a Planar Inverted F Antenna (PIFA).
• Experiments and numerical simulations were conducted at varying distances to assess exposure compliance based on SAR and IPD limits.
• The results indicate a significant transition where the highest power reduction for compliance switches from SAR to IPD between distances of 5 and 10 mm, with a variable discontinuity level of 2 to 6 dB dependent on distance and source.

Conclusion

At closer proximity, SAR proves to be more restrictive, while IPD leads to increased back-off power as the distance increases, which highlights potential health risks associated with electromagnetic fields at different exposure metrics and distances.