Whole-body SAR measurements of millimeter-wave base station in reverberation chambers

Authors: Eilers Bischoff J, Joshi P, Colombi D, Xu B, Törnevik C

Year: 2024

Category: Electromagnetic Exposure Assessment

Journal: International Journal of Microwave and Wireless Technologies

DOI: 10.1017/S1759078724000515

URL: https://doi.org/10.1017/S1759078724000515

Abstract

Overview

This paper presents a method for measuring whole-body specific absorption rate (WBSAR) of millimeter-wave base stations (BSs) in a reverberation chamber (RC). The technique involves placing a phantom (a model simulating human tissue) in the RC and recording the absorbed power from the equipment under test (EUT). The WBSAR is then calculated as the difference in total radiated power with and without the phantom.

Measurement Approach

  • Absorbed power in the phantom comes from direct illumination by the EUT, with multipath reflections within the RC excluded using a chamber transfer function.
  • The method was tested at 28 GHz using both a horn antenna and a commercial massive multi-input-multi-output base station.

Findings

  • Experimental results showed strong agreement with simulation data.
  • The procedure can measure WBSAR within 3 minutes, a significant reduction in time compared to conventional assessment techniques.

Conclusion

This measurement method is suitable for compliance testing of base station products with the International Commission on Non-Ionizing Radiation Protection (ICNIRP) 2020 electromagnetic field exposure guidelines. These guidelines extend the use of WBSAR as a basic restriction up to frequencies of 300 GHz, supporting broader assessments of EMF safety and addressing health risk concerns from electromagnetic fields.

whole-body SAR millimeter-wave base station reverberation chamber electromagnetic field exposure assessment compliance testing
← Back to Stats