Radio frequencies
A comparison of ITU, ISM, IEEE radar and NATO bands with ranges, wavelengths and representative uses.
Written and technically reviewed byElectroDesignForge Engineering Team
View the editorial process📡 Reference guide
Radio-frequency band names are convenient shorthand, but several naming systems coexist. UHF, L band, C band or NATO C band do not necessarily describe the same frequency interval.
The tables below compare the principal ITU, ISM, IEEE radar and NATO / EU / US ECM designations, together with representative uses.
Quick Reference
| System | Coverage | Primary purpose |
|---|---|---|
| ITU band numbers and names | 3 Hz–3 THz | General telecommunications nomenclature |
| ITU ISM designations | Discrete bands from 6.78 MHz to 245 GHz | Industrial, scientific and medical applications |
| IEEE radar letter bands | 3 MHz–300 GHz | Radar engineering and related microwave usage |
| NATO / EU / US ECM bands | 0–100 GHz | Military electronic-warfare spectrum designation |
Important: a band name describes a frequency range, not a licence or an allocation. Always check the current national frequency plan, permitted power, duty cycle, channel plan and equipment requirements before transmitting.
ITU Radio-Frequency Band Nomenclature
The ITU system divides the spectrum into decades. In the formal ITU notation, the lower limit is excluded and the upper limit is included.
| No. | Symbol | English name | Frequency range | Approx. wavelength | Typical uses |
|---|---|---|---|---|---|
| 1 | ELF | Extremely Low Frequency | 3–30 Hz | 100,000–10,000 km | Geophysics, extremely low-rate through-water communication |
| 2 | SLF | Super Low Frequency | 30–300 Hz | 10,000–1,000 km | Submarine communication, geophysical studies |
| 3 | ULF | Ultra Low Frequency | 300 Hz–3 kHz | 1,000–100 km | Through-earth links, mine communication, geophysics |
| 4 | VLF | Very Low Frequency | 3–30 kHz | 100–10 km | Time signals, navigation, submarine communication |
| 5 | LF | Low Frequency | 30–300 kHz | 10–1 km | Long-wave broadcasting, beacons, low-frequency RFID |
| 6 | MF | Medium Frequency | 300 kHz–3 MHz | 1 km–100 m | AM broadcasting, maritime and aeronautical services |
| 7 | HF | High Frequency | 3–30 MHz | 100–10 m | Short-wave broadcasting, amateur radio, long-range skywave links |
| 8 | VHF | Very High Frequency | 30–300 MHz | 10–1 m | FM radio, television, airband, marine and land-mobile radio |
| 9 | UHF | Ultra High Frequency | 300 MHz–3 GHz | 1 m–100 mm | Television, cellular, GNSS, 2.4 GHz Wi-Fi/Bluetooth, radar |
| 10 | SHF | Super High Frequency | 3–30 GHz | 100–10 mm | Microwave links, satellite communication, radar, 5/6 GHz Wi-Fi |
| 11 | EHF | Extremely High Frequency | 30–300 GHz | 10–1 mm | Millimetre-wave radar, high-capacity links, remote sensing |
| 12 | THF | Tremendously High Frequency | 300 GHz–3 THz | 1 mm–100 µm | Terahertz imaging, spectroscopy and research |
Uses are representative only: formal allocations depend on the ITU Region and national regulations.
ITU ISM Bands
ISM means industrial, scientific and medical. Radio systems such as RFID, Wi-Fi, Bluetooth, Zigbee or LoRa commonly share some of these ranges under separate radio-device rules; they are not themselves automatically classified as ISM equipment.
| Frequency range | Centre frequency | ITU scope | Common ISM or shared-radio examples |
|---|---|---|---|
| 6.765–6.795 MHz | 6.780 MHz | Worldwide; special authorization | Induction heating, plasma and industrial processing |
| 13.553–13.567 MHz | 13.560 MHz | Worldwide | RFID, NFC, induction heating |
| 26.957–27.283 MHz | 27.120 MHz | Worldwide | Industrial heating, diathermy, short-range devices where permitted |
| 40.66–40.70 MHz | 40.68 MHz | Worldwide | Industrial heating, telemetry and short-range devices where permitted |
| 433.05–434.79 MHz | 433.92 MHz | ITU Region 1, with country exceptions; special authorization | Short-range sensors, remote controls, telemetry |
| 902–928 MHz | 915 MHz | ITU Region 2 | UHF RFID, LoRa/LPWAN, telemetry |
| 2.400–2.500 GHz | 2.450 GHz | Worldwide | Microwave heating, Wi-Fi, Bluetooth, IEEE 802.15.4 |
| 5.725–5.875 GHz | 5.800 GHz | Worldwide | Industrial heating, RFID, short-range and WLAN systems where permitted |
| 24.00–24.25 GHz | 24.125 GHz | Worldwide | Motion, presence, level and short-range radar sensors |
| 61.0–61.5 GHz | 61.25 GHz | Worldwide; special authorization | Millimetre-wave sensing and short-range links |
| 122–123 GHz | 122.5 GHz | Worldwide; special authorization | High-resolution sensing, spectroscopy |
| 244–246 GHz | 245 GHz | Worldwide; special authorization | Imaging, spectroscopy and scientific research |
Under ITU Radio Regulations Nos. 5.138 and 5.150, the regional conditions differ. Radiocommunication services operating in the No. 5.150 bands must accept harmful interference from ISM applications. National licence-exempt ranges can be narrower than the ITU designation; for example, European 433 MHz and 868 MHz SRD rules must not be inferred from this table.
IEEE Radar-Frequency Bands
The IEEE 521 family standardizes letter designations used in radar engineering. The same letters are also used informally for satellite and microwave systems, sometimes with different limits.
| Band | Frequency range | Approx. wavelength | Typical radar and microwave uses |
|---|---|---|---|
| HF | 3–30 MHz | 100–10 m | Over-the-horizon radar, ionospheric sensing |
| VHF | 30–300 MHz | 10–1 m | Long-range surveillance, foliage-penetration research |
| UHF | 300 MHz–1 GHz | 1 m–30 cm | Early warning, space surveillance, long-range detection |
| L | 1–2 GHz | 30–15 cm | Air surveillance, tracking, long-range radar |
| S | 2–4 GHz | 15–7.5 cm | Weather, marine and air-traffic-control radar |
| C | 4–8 GHz | 7.5–3.75 cm | Weather radar, tracking, satellite and microwave links |
| X | 8–12 GHz | 3.75–2.5 cm | Marine radar, imaging, mapping and fire control |
| Ku | 12–18 GHz | 2.5–1.67 cm | High-resolution radar, satellite links, speed measurement |
| K | 18–27 GHz | 1.67–1.11 cm | Short-range radar and sensing; atmospheric absorption near 22 GHz |
| Ka | 27–40 GHz | 11.1–7.5 mm | High-resolution radar, satellite broadband, altimetry |
| V | 40–75 GHz | 7.5–4 mm | Short-range links, research radar, strong absorption near 60 GHz |
| W | 75–110 GHz | 4–2.73 mm | Automotive radar, security imaging, remote sensing |
| mm | 110–300 GHz | 2.73–1 mm | Millimetre-wave imaging, spectroscopy and experimental radar |
Do not mix designation systems: IEEE C band is 4–8 GHz, while NATO/ECM C band is 500 MHz–1 GHz.
NATO / EU / US ECM Frequency Designations
These letter bands are used in military electronic warfare and spectrum-management contexts. They deliberately differ from IEEE radar bands.
| Band | Frequency range | Broad spectrum area | Representative context |
|---|---|---|---|
| A | 0–250 MHz | ELF through most of VHF | HF/VHF communications, navigation and surveillance |
| B | 250–500 MHz | Upper VHF / lower UHF | Tactical communication and surveillance |
| C | 500 MHz–1 GHz | UHF | Communication, telemetry and long-range radar |
| D | 1–2 GHz | UHF / IEEE L | Surveillance, navigation and satellite links |
| E | 2–3 GHz | UHF / IEEE S | Radar, telemetry and communication |
| F | 3–4 GHz | SHF / IEEE S | Air and weather surveillance radar |
| G | 4–6 GHz | SHF / IEEE C | Radar, microwave and satellite links |
| H | 6–8 GHz | SHF / IEEE C | Tracking radar and fixed/satellite links |
| I | 8–10 GHz | SHF / IEEE X | Imaging, tracking and fire-control radar |
| J | 10–20 GHz | SHF / IEEE X, Ku and K | High-resolution radar and satellite links |
| K | 20–40 GHz | SHF/EHF / IEEE K and Ka | Precision radar, seekers and high-capacity links |
| L | 40–60 GHz | EHF / IEEE V | Millimetre-wave sensing and short-range links |
| M | 60–100 GHz | EHF / IEEE V and W | Millimetre-wave radar, imaging and electronic support |
How to Read an RF Band Name
- Identify the naming system. “L band” generally suggests IEEE radar/microwave usage, while “NATO L band” means 40–60 GHz.
- State numerical limits. For specifications and compliance work, write the actual range in MHz or GHz.
- Check the region. ITU Regions 1, 2 and 3 do not share every allocation or ISM designation.
- Check local rules. Allocation, licence exemption, EIRP, bandwidth, duty cycle, indoor/outdoor use and equipment conformity are separate questions.
The free-space relationship between frequency and wavelength is:
λ = c / f
Where λ is wavelength, f is frequency and c ≈ 299,792,458 m/s. Use the wavelength calculator for exact conversions.
Bibliography
- ITU-R V.431-9 — Nomenclature of frequency and wavelength bands
- ITU Radio Regulations, 2024 edition — Volume 1, Nos. 5.138 and 5.150
- IEEE 521-2026 — Standard Letter Designations for Radar-Frequency Bands
- NASA — Spectrum band designators and bandwidths
- NTIA — Radar Frequencies and Waveforms
- Qatar Communications Regulatory Authority — National Frequency Allocation Plan