D HUMAN-MADE RF SOURCES
D.1 TRANSMITTERS BY FREQUENCY RANGE
The following survey groups representative RF transmitters according to their principal operating frequency ranges. These groupings are intended as practical application categories rather than rigid ITU band classifications, since many modern systems operate across band boundaries or use several widely separated frequency ranges. The quoted powers are representative rather than definitive and may refer to conducted transmitter output, carrier power, peak-envelope power, peak pulse power, ERP, or EIRP, depending on the type of system. They should therefore be interpreted together with the qualifications given for each application and not compared directly without considering antenna gain, modulation, duty cycle, and operating conditions.
HF. Typical rated HF transmitter output power ratings, generally peak-envelope power (PEP):
- Amateur radio: portable equipment commonly provides 5–20 W, while fixed and mobile transceivers commonly provide up to 100°W PEP. External amplifiers may provide 500 W–1.5 kW PEP, subject to national limits; the general US maximum is 1.5 kW PEP.
- Military communications: manpack radios commonly provide 5–20 W. Vehicle-mounted, airborne, shipboard, and normal base-station systems commonly fall within the 100–400 W class. Fixed strategic installations may operate at 500 W, 1 kW, or several kilowatts.
- Maritime communications: ordinary shipboard MF/HF SSB equipment is commonly rated at approximately 125–150 W PEP. Naval vessels and coast stations may use outputs ranging from several hundred watts to several kilowatts.
- Aviation communications: installed airborne HF systems commonly provide approximately 200–400 W PEP, although lower-power systems in the 100–200 W range are also used.
- Commercial and government fixed communications: equipment ranges from approximately 100 W to 1 kW for many applications. High-reliability and strategic stations may use transmitters rated at several kilowatts.
- Shortwave broadcasting: smaller and regional stations may use approximately 10–50 kW, while major international stations commonly use 100–500 kW transmitters.
VHF. Typical rated VHF transmitter powers are as follows. The listed values normally describe maximum RF output during transmission. Broadcast FM is different because it operates continuously and is usually specified by effective radiated power (ERP), not simply transmitter output.
- Land-mobile radio: handheld units commonly provide 1–5 W; vehicle-mounted radios generally provide 25–50 W, with some models reaching approximately 65 W; base and repeater stations commonly use 25–100 W transmitters.
- Amateur radio: handheld transceivers commonly provide 1–5 W, although some reach 7–8 W. Mobile and fixed transceivers generally provide 25–50 W, with some dedicated VHF models rated at approximately 65–75 W.
- Maritime radio: handheld units commonly provide selectable outputs up to 5 or 6 W. Fixed shipboard radios normally provide approximately 1 W on low power and 25 W on high power.
- Aviation communications: handheld or low-power radios may provide approximately 5–6 W, while installed aircraft VHF radios commonly provide 10–16 W.
- Public-safety and emergency communications: handheld radios commonly provide 1–5 W; vehicle-mounted equipment generally provides 25–50 W; and fixed base or repeater stations commonly operate in the 25–100 W range.
- Commercial land-mobile radio: handheld units commonly provide 1–5 W, while mobile and ordinary fixed units generally provide 25–50 W; some VHF models reach approximately 65 W.
- FM broadcasting: small community, translator, and low-power stations may operate from approximately 10 W to 1 kW ERP. Conventional stations commonly operate at several kilowatts to tens of kilowatts, while major stations may reach approximately 100 kW ERP.
UHF. Typical rated UHF transmitter powers are as follows. These values generally represent conducted transmitter output while the equipment is transmitting. Broadcast figures are normally expressed as ERP, while the actual time-averaged power from intermittent two-way and IoT equipment is reduced by duty cycle, traffic loading, and power-control behavior.
- Land-mobile radio: handheld units commonly provide 1–5 W; vehicle-mounted radios generally provide 25–50 W; and base or repeater stations commonly operate at 25–100 W.
- Amateur radio: handheld transceivers commonly provide 1–5 W, although some models reach 7–8 W. Mobile and fixed transceivers generally provide 10–50 W, excluding external amplifiers.
- Maritime on-board radio: portable UHF radios used for internal ship communications commonly operate at 1–5 W. Normal maritime ship-to-ship and ship-to-shore voice communication uses VHF.
- Military aviation radio: portable equipment may provide 2–10 W, while installed UHF radios commonly provide approximately 10–25 W. Civil aviation voice communication normally uses VHF.
- Public-safety and emergency radio: handheld units commonly provide 1–5 W; vehicle-mounted radios generally provide 25–50 W, with some approaching 100 W; and base or repeater stations commonly operate at 25–100 W.
- Commercial UHF radio: handheld units commonly provide 1–5 W; mobile radios generally provide 25–50 W; and fixed base or repeater stations commonly provide 25–100 W.
- Military tactical radio: handheld and manpack equipment commonly provides 2–20 W, while vehicle-mounted and ordinary fixed installations commonly operate in the 20–100 W range.
- UHF television broadcasting: low-power and translator stations may operate from tens of watts to several kilowatts ERP. Full-power stations commonly operate at tens to several hundreds of kilowatts ERP and may reach approximately 1 MW ERP in some jurisdictions.
- Consumer and recreational radio: most personal devices operate from tens of milliwatts to approximately 2 W. Australian UHF CB equipment commonly provides up to 5 W; some licensed mobile services elsewhere permit up to 50 W.
- Industrial and IoT equipment: sensors and short-range devices commonly operate at 1–100 mW. Longer-range telemetry and industrial systems may use several hundred milliwatts to approximately 1 W, with higher powers reserved mainly for specialized licensed systems.
SHF. Typical SHF rated transmitter powers follow. These figures describe different power quantities and should not be compared without qualification. Communications equipment is normally specified by conducted transmitter output or EIRP, whereas radar is commonly specified by peak pulse power. For exposure assessment, antenna gain, modulation, pulse duty cycle, traffic loading, beam direction, scanning behavior, and the applicable averaging period must also be considered.
- Military communications: portable microwave and satellite terminals commonly provide approximately 1–20 W of conducted RF output; specialized transportable systems may provide several tens of watts or more.
- Military radar: surveillance, tracking, and fire-control systems range from several kilowatts to hundreds of kilowatts peak, while some long-range radars exceed 1 MW peak. Mean power is much lower and depends on duty cycle.
- Fixed microwave links: conducted transmitter power commonly ranges from approximately 0.1–10 W per channel. Some long-haul lower-frequency systems may operate in the 10–50 W range.
- Satellite communications: large earth stations commonly use 50 W–1 kW amplifiers, with still higher ratings possible. VSATs commonly use 1–10 W, although 20–50 W units are available. Portable terminals range from less than 1 W to several tens of watts.
- Civil aviation radar: short-range systems may operate from hundreds of watts to several kilowatts peak. Primary surveillance radars commonly use tens to hundreds of kilowatts peak, with some long-range systems reaching 1 MW or more.
- Weather radar: compact systems may use less than 1 kW to several tens of kilowatts peak; major C-band and S-band systems commonly use tens to several hundreds of kilowatts peak.
- Automotive radar: conducted output is commonly in the milliwatt-to-sub-watt range, while directional EIRP may amount to several watts or more. Most automotive radar operates above 30 GHz and is not formally within SHF.
- 5 GHz Wi-Fi: access points commonly provide approximately 0.05–1 W conducted output; client devices generally use tens to several hundreds of milliwatts.
- 5G FR1: macro radios commonly provide tens of watts per transmitter branch, while aggregate multi-antenna radio output may reach tens to several hundreds of watts. Small cells use less than 1 W to several watts per channel.
- 5G FR2: individual antenna elements operate at relatively low powers, but phased-array gain creates high directional EIRP. Mobile phones ordinarily have maximum conducted powers around 0.2 W rather than several watts.
Short-range and IoT systems. Typical transmitter powers of selected short-range and IoT systems:
- Bluetooth: 2.4 GHz; typically 0.1–10 mW for phones, peripherals, and wearables, with higher-power equipment operating at up to 100 mW. Ordinary range is several meters to tens of meters, although optimized Bluetooth LE links may extend much farther.
- Zigbee: 2.4 GHz worldwide, with regional sub-GHz operation near 868 and 915 MHz. Typical power is approximately 1–20 mW, although some range-extended equipment approaches 100 mW. Individual links commonly cover 10–100 m; favorable sub-GHz links may reach 1 km or more.
- LoRa/LoRaWAN: commonly operates near 868 or 915 MHz, depending on region. End-device outputs are typically about 25–160 mW. Representative ranges are 2–5 km in urban areas and 10–15 km in open rural environments; exceptional line-of-sight links may exceed 50 km.
- Ultra-wideband: commonly uses frequencies within 3.1–10.6 GHz. Its emissions are limited by very low power spectral density, and total radiated power is generally below about 0.5 mW. Typical consumer operating range is several meters to a few tens of meters.
- Near-field communication: operates at 13.56 MHz over a few centimeters, normally less than 10 cm. It relies on inductive magnetic coupling, so magnetic-field strength is a more appropriate descriptor than radiated power. Ordinary reader circuitry may operate at tens to hundreds of milliwatts; separate NFC charging systems can transfer up to approximately 1 W.
