Abstract

Abstract Summary

The recent advancements in mobile communication, specifically long-term evolution (LTE) and 5G new radio (NR), use digitally modulated signals that significantly alter the functionality of diode-based wideband electric field probes. This results in a potential overestimation of electromagnetic field strength, posing risks in compliance with safety standards.

Overview

This study investigates the response of broadband electric field probes to 5G NR signals by contrasting these readings with those obtained under continuous wave (CW) radiation. The focus is on various signal parameters like center frequency, modulation complexity, and signal bandwidth.

Findings

• The probes overestimate field strength by as much as several tens of percent when exposed to 5G signals compared to CW signals.
• Calibration standards need revision to include varying behaviors of probes with 5G and CW signals.
• Detailed experimental analysis reveals that the overestimation factor can vary significantly depending on the signal’s center frequency, frame occupation, and bandwidth.

Conclusion

Given the high crest factor of 5G signals, probes tend to overestimate amplitude, potentially leading to non-compliance with exposure limits. Adopting a variable attenuator at the diode’s input could help maintain the probe's accuracy by keeping the working point within the quadratic region of response. Therefore, caution is advised when using diode-based sensor probes for measuring electromagnetic fields of expected strengths larger than 6 V/m.