Can body-worn devices be used for measuring personal exposure to mm waves?

Abstract

Can body-worn devices be used for measuring personal exposure to mm waves? Thielens A, Martens L, Joseph W. Can body-worn devices be used for measuring personal exposure to mm waves? Bioelectromagnetics. 2017 Jan 20. doi: 10.1002/bem.22036. Abstract Fifth generation (5G) telecommunication networks will require more bandwidth and will use mm waves (30- 300 GHz). Consequently, the aperture of antennas that are used for electromagnetic field measurements will be reduced in comparison to the ones currently used for lower frequencies (0.1-6 GHz). In combination with existing limits on incident power density prescribed by exposure guidelines, this provides an upper limit to received powers during exposure measurements. Simultaneously, an increase in the noise floor of transmitted signals will occur. These effects limit the dynamic range of measurements to 53 dB (2 × 105 ) at 300 GHz and 73 dB (2 × 107 ) at 30 GHz, which are determined using a simplified model. Additional propagation losses that exceed this dynamic range can occur during on-body measurements. Therefore, in future wireless networks, an on-body measurement of the incident power density cannot be guaranteed using a single antenna. This effect is problematic for both occupational measurements and epidemiological studies. We propose to use multiple, dynamic antennas on the body instead. ncbi.nlm.nih.gov

AI evidence extraction

Main findings

Using a simplified model, the authors estimate measurement dynamic range limits of 53 dB at 300 GHz and 73 dB at 30 GHz due to reduced antenna aperture, exposure guideline limits on incident power density, and increased noise floor. They state that additional on-body propagation losses can exceed this dynamic range, so on-body measurement of incident power density cannot be guaranteed using a single antenna; they propose multiple dynamic antennas on the body instead.

Outcomes measured

• Feasibility/limitations of on-body personal exposure measurements at mmWave frequencies
• Dynamic range limits for incident power density measurements (model-based)

Limitations

• Results are based on a simplified model (as stated)
• No empirical measurement data described in the abstract

Suggested hubs

• 5g-policy (0.62)
  Discusses mmWave (30–300 GHz) exposure measurement challenges in the context of future 5G networks.
• occupational-exposure (0.55)
  Abstract explicitly notes the issue is problematic for occupational measurements.

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    "study_type": "engineering",
    "exposure": {
        "band": "mmWave",
        "source": "5G telecommunication networks",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": null,
    "sample_size": null,
    "outcomes": [
        "Feasibility/limitations of on-body personal exposure measurements at mmWave frequencies",
        "Dynamic range limits for incident power density measurements (model-based)"
    ],
    "main_findings": "Using a simplified model, the authors estimate measurement dynamic range limits of 53 dB at 300 GHz and 73 dB at 30 GHz due to reduced antenna aperture, exposure guideline limits on incident power density, and increased noise floor. They state that additional on-body propagation losses can exceed this dynamic range, so on-body measurement of incident power density cannot be guaranteed using a single antenna; they propose multiple dynamic antennas on the body instead.",
    "effect_direction": "unclear",
    "limitations": [
        "Results are based on a simplified model (as stated)",
        "No empirical measurement data described in the abstract"
    ],
    "evidence_strength": "insufficient",
    "confidence": 0.7399999999999999911182158029987476766109466552734375,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "5G",
        "millimeter waves",
        "mmWave",
        "30-300 GHz",
        "personal exposure",
        "body-worn devices",
        "on-body measurements",
        "incident power density",
        "dynamic range",
        "antenna aperture",
        "occupational measurements",
        "epidemiological studies"
    ],
    "suggested_hubs": [
        {
            "slug": "5g-policy",
            "weight": 0.61999999999999999555910790149937383830547332763671875,
            "reason": "Discusses mmWave (30–300 GHz) exposure measurement challenges in the context of future 5G networks."
        },
        {
            "slug": "occupational-exposure",
            "weight": 0.5500000000000000444089209850062616169452667236328125,
            "reason": "Abstract explicitly notes the issue is problematic for occupational measurements."
        }
    ]
}

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