How 5G NR Signals Impact on the Response of Broadband Electric Field Probes

2023 · Mixed · Moderate evidence

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MixedModerate evidencePaper 472

Study snapshot

Publicationmanual · 2023

Study typeengineering

Reported directionMixed

Evidence ratingModerate

Abstract

How 5G NR Signals Impact on the Response of Broadband Electric Field Probes Adda S, Anglesio L, Bogo F, Pasquino N, Trinchero S. How 5G NR Signals Impact on the Response of Broadband Electric Field Probes. IEEE Transactions on Instrumentation and Measurement, vol. 72, pp. 1-8, 2023, Art no. 8000208, doi: 10.1109/TIM.2022.3227979. Abstract New-generation mobile communication systems like long term evolution (LTE) and 5G new radio (NR) use digitally modulated signals with relevant peak-to-average power ratios that may shift the working point of diode-based wideband electric field probes, resulting in an overestimation of the field strength. This article presents a methodology to study the behavior of probes by comparing the readings of 5G signals to those obtained under continuous wave (CW) radiation. Dependence on various signal parameters like center frequency, modulation complexity, time/frequency duplex configuration, signal bandwidth, and orthogonal frequency-division multiplexing (OFDM) subcarrier spacing has been assessed experimentally by making use of test models designed by 3rd generation partnership project (3GPP). Results show that overestimation can be as large as several tens of percent and that it is greater for full-frame and larger bandwidth signals and that, therefore, calibration standards must be extended to consider the different behavior of probes with 5G and CW signals. Conclusion Diode-loaded electric field probes have been exposed to 5G signals to investigate the different behavior compared to continuous waves, in terms of under- or over-estimation. Test signals based on models suggested by ETSI have been used to assess the impact of signal center frequency, frame occupation, bandwidth, modulation, duplex configuration, and subcarrier spacing. Results show that, due to the high crest factor of 5G signals, probes tend to overestimate amplitude when exposed to high test fields, because the diode overcomes the quadratic region and responds to the peak strength rather than to the rms value of the incident field. A possible solution would be to adopt a variable attenuator at the diode’s input that keeps the working point within the quadratic region. The analysis of the overestimation factor K shows that overestimation can be as large as several tens of percent and that it spans from 1.07 to 1.225 at 3700 MHz with TDD configuration and μ=1 , being greater for full-frame and larger bandwidth signals. Experimental results prove that diode-based sensor probes should be used with caution when electromagnetic fields of expected strengths larger than 6 V/m are measured, to avoid that, due to overestimation, they return a measurement that shows not compliant with exposure limits. Open access paper: ieeexplore.ieee.org

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeengineering

Effect directionmixed

PopulationNot supplied

Sample sizeNot supplied

ExposureRF · 3700 MHz

Evidence strengthModerateConfidence: 78% · Peer reviewed: yes

Main findings

Digitally modulated LTE/5G NR signals with high peak-to-average power ratios can shift the working point of diode-based wideband electric field probes, leading to overestimation of field strength compared with CW radiation. Experimentally, overestimation was reported as large as several tens of percent; at 3700 MHz in TDD configuration (μ=1) the overestimation factor K spanned 1.07 to 1.225 and was greater for full-frame and larger bandwidth signals.

Outcomes measured

Broadband electric field probe response under 5G NR vs continuous wave (CW) radiation
Degree of under-/over-estimation of electric field strength readings
Dependence of probe response on signal parameters (center frequency, modulation complexity, duplex configuration, bandwidth, OFDM subcarrier spacing, frame occupation)
Overestimation factor K (reported range at 3700 MHz)
Implications for calibration standards and compliance measurements (e.g., >6 V/m)

View raw extracted JSON

{
  "study_type": "engineering",
  "exposure": {
    "band": "RF",
    "source": "5G NR test signals / continuous wave comparison",
    "frequency_mhz": 3700,
    "sar_wkg": null,
    "duration": null
  },
  "population": null,
  "sample_size": null,
  "outcomes": [
    "Broadband electric field probe response under 5G NR vs continuous wave (CW) radiation",
    "Degree of under-/over-estimation of electric field strength readings",
    "Dependence of probe response on signal parameters (center frequency, modulation complexity, duplex configuration, bandwidth, OFDM subcarrier spacing, frame occupation)",
    "Overestimation factor K (reported range at 3700 MHz)",
    "Implications for calibration standards and compliance measurements (e.g., >6 V/m)"
  ],
  "main_findings": "Digitally modulated LTE/5G NR signals with high peak-to-average power ratios can shift the working point of diode-based wideband electric field probes, leading to overestimation of field strength compared with CW radiation. Experimentally, overestimation was reported as large as several tens of percent; at 3700 MHz in TDD configuration (μ=1) the overestimation factor K spanned 1.07 to 1.225 and was greater for full-frame and larger bandwidth signals.",
  "effect_direction": "mixed",
  "limitations": [],
  "evidence_strength": "moderate",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "5G NR",
    "LTE",
    "broadband electric field probes",
    "diode-based probes",
    "crest factor",
    "peak-to-average power ratio",
    "continuous wave",
    "OFDM",
    "TDD",
    "calibration",
    "exposure compliance",
    "3700 MHz"
  ],
  "suggested_hubs": [
    {
      "slug": "5g-policy",
      "weight": 0.62,
      "reason": "Study concerns 5G NR signal characteristics and implications for exposure/compliance measurements."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1109/tim.2022.3227979
PubMed: Not supplied

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