{
  "id": "emitters:smartphone",
  "collection": "emitters",
  "slug": "smartphone",
  "name": "Smartphone (cellular uplink)",
  "summary": "Handsets transmit up to about 200 mW (23 dBm) on cellular uplink and are used against the head, so exposure is governed by SAR — 1.6 W/kg over 1 g in the U.S., 2 W/kg over 10 g under ICNIRP — not by power density.",
  "status": "verified",
  "lastVerified": "2026-08-12",
  "data": {
    "aliases": [
      "mobile phone",
      "cell phone",
      "phone radiation"
    ],
    "category": "radiofrequency",
    "environment": [
      "home",
      "workplace",
      "vehicle",
      "school"
    ],
    "bands": [
      {
        "label": "Cellular uplink (700 MHz–3.8 GHz)",
        "minHz": 700000000,
        "maxHz": 3800000000
      },
      {
        "label": "Wi-Fi / Bluetooth",
        "minHz": 2400000000,
        "maxHz": 5900000000
      }
    ],
    "transmitPower": {
      "quantity": "power",
      "unit": "W EIRP",
      "value": 0.2,
      "basis": "regulatory",
      "note": "23 dBm is the typical LTE/5G-NR power class maximum for handsets. Phones transmit far below this when signal is strong, and at the maximum when signal is weak.",
      "sourceIds": [
        "fcc-2-1093"
      ]
    },
    "dutyCycle": "Uplink power is adaptive: one or two bars of signal can mean orders of magnitude more transmit power than full bars for the same call.",
    "distanceProfile": [
      {
        "meters": 0.01,
        "value": {
          "quantity": "specific-absorption-rate",
          "unit": "W/kg",
          "value": 0.2,
          "max": 1.6,
          "basis": "manufacturer",
          "note": "Reported head SAR for handsets sold in the U.S. must not exceed 1.6 W/kg over 1 g at maximum transmit power. Per-model values are in the FCC equipment authorization filing for the device's FCC ID.",
          "sourceIds": [
            "fcc-2-1093",
            "fcc-eas"
          ]
        }
      },
      {
        "meters": 0.3,
        "value": {
          "quantity": "power-density",
          "unit": "µW/m²",
          "value": 177000,
          "basis": "computed",
          "method": "S = EIRP / (4πd²) with EIRP = 0.2 W, d = 0.3 m",
          "note": "Far-field approximation only; at 30 cm the phone is roughly one wavelength away at 1 GHz.",
          "sourceIds": [
            "fcc-2-1093"
          ]
        }
      },
      {
        "meters": 1,
        "value": {
          "quantity": "power-density",
          "unit": "µW/m²",
          "value": 15900,
          "basis": "computed",
          "method": "S = EIRP / (4πd²) with EIRP = 0.2 W, d = 1 m",
          "sourceIds": [
            "fcc-2-1093"
          ]
        }
      }
    ],
    "mitigations": [
      {
        "action": "Use speakerphone or wired earphones instead of holding the phone to the head.",
        "effect": "Moving the transmitter from 1 cm to 30 cm removes almost all of the local SAR.",
        "sourceIds": [
          "who-emf-rf"
        ]
      },
      {
        "action": "Make calls where signal is strong, and avoid calling from lifts, basements or moving vehicles.",
        "effect": "Adaptive power control means good signal directly reduces transmit power."
      },
      {
        "action": "Prefer Wi-Fi calling and data over cellular when available; keep the phone off the body when transmitting.",
        "effect": "Wi-Fi uplink power is typically an order of magnitude below cellular uplink maximum."
      },
      {
        "action": "Look up your model's SAR in the FCC equipment authorization database rather than relying on third-party lists.",
        "effect": "Gives the tested value for the exact hardware revision.",
        "sourceIds": [
          "fcc-eas"
        ]
      }
    ],
    "measureWith": [
      "broadband-rf-meter"
    ],
    "related": [
      "limits:fcc-sar-partial-body",
      "limits:icnirp-2020-sar-local",
      "studies:iarc-2b-rf-2011"
    ],
    "questions": [
      "what-is-sar-and-does-a-low-sar-phone-matter"
    ]
  },
  "sources": [
    {
      "id": "fcc-2-1093",
      "title": "47 CFR § 2.1093 — Radiofrequency radiation exposure evaluation: portable devices",
      "publisher": "U.S. Government Publishing Office (eCFR)",
      "url": "https://www.ecfr.gov/current/title-47/section-2.1093",
      "kind": "regulation",
      "retrieved": "2026-08-12"
    },
    {
      "id": "fcc-eas",
      "title": "Equipment Authorization Search (FCC ID lookup, includes SAR test reports)",
      "publisher": "Federal Communications Commission",
      "url": "https://www.fcc.gov/oet/ea/fccid",
      "kind": "government",
      "retrieved": "2026-08-12"
    },
    {
      "id": "who-emf-rf",
      "title": "Radiation: Electromagnetic fields (questions and answers)",
      "publisher": "World Health Organization",
      "url": "https://www.who.int/news-room/questions-and-answers/item/radiation-electromagnetic-fields",
      "kind": "government",
      "retrieved": "2026-08-12"
    },
    {
      "id": "icnirp-2020",
      "title": "Guidelines for Limiting Exposure to Electromagnetic Fields (100 kHz to 300 GHz)",
      "publisher": "International Commission on Non-Ionizing Radiation Protection",
      "url": "https://www.icnirp.org/en/publications/article/rf-guidelines-2020.html",
      "year": 2020,
      "kind": "guideline",
      "retrieved": "2026-08-12"
    }
  ],
  "links": {
    "self": "https://emfbase.com/api/emitters/smartphone",
    "html": "https://emfbase.com/emitters/smartphone",
    "markdown": "https://emfbase.com/emitters/smartphone.md",
    "collection": "https://emfbase.com/api/emitters"
  }
}