Radio Frequency Bands

The certified spectral range of our sub-terahertz imaging cameras (50 GHz – 0.7 THz) borders with other portions of electromagnetic spectrum, and therefore it makes sense for us to describe briefly the adjacent spans and their peculiarities.

The radio spectrum (also known as radio frequency or RF) is one of such parts of the electromagnetic spectrum that overlaps our sub-THz range at its lower end. Accordingly, Electromagnetic waves in this frequency range are called radio frequency bands or simply ‘radio waves’. RF bands spread in the range between 30 kHz and 300 GHz (alternative point of view offers coverage 3 KHz – 300 GHz). All known transmission systems are operated in the RF spectrum range including analogue radio, aircraft navigation, marine radio, amateur radio, TV broadcasting, mobile networks and satellite systems.

Radio frequency bands

RF frequency bands

To prevent interference between different users, the generation and transmission of radio frequency bands is strictly regulated by national laws, coordinated by an international body, the International Telecommunication Union (ITU). The ITU (based in Geneva, Switzerland) is a member of UN development group, coordinates the shared global use of the radio spectrum, promotes international cooperation in assigning satellite orbits, works to improve telecommunication infrastructure in the developing world, and assists in the development and coordination of worldwide technical standards.

Different parts of the radio spectrum (RF bands) are allocated by the ITU for different radio transmission technologies and applications; some 40 radio communication services are defined in the ITU’s Radio Regulations (RR).

A radio frequency band is a small contiguous section of the radio spectrum frequencies, in which channels are usually used or set aside for use. For example, broadcasting, mobile radio, or navigation devices, will be allocated in non-overlapping ranges of frequencies. For each of these bands the ITU has a band plan which dictates how it is to be used and shared, to avoid interference and to set protocol for the compatibility of transmitters and receivers.

Pursuant to convention, the ITU divides the radio spectrum into 12 bands (as shown in the table below), each beginning at a wavelength which is a power of ten (10n) metres, with corresponding frequency of 3×108−n hertz, and each covering a decade of frequency or wavelength. Each of these bands has a traditional name.

Band name


ITU band number



Example Uses

Extremely low frequency



3–30 Hz

100,000–10,000 km

Communication with submarines

Super low frequency



30–300 Hz

10,000–1,000 km

Communication with submarines

Ultra low frequency



300–3,000 Hz

1,000–100 km

Submarine communication, communication within mines

Very low frequency



3–30 kHz

100–10 km

Navigation, time signals, submarine communication, wireless heart rate monitors, geophysics

Low frequency



30–300 kHz

10–1 km

Navigation, time signals, AM longwave broadcasting (Europe and parts of Asia), RFID, amateur radio

Medium frequency



300–3,000 kHz

1,000–100 m

AM (medium-wave) broadcasts, amateur radio, avalanche beacons

High frequency



3–30 MHz

100–10 m

Shortwave broadcasts, citizens band radio, amateur radio and over-the-horizon aviation communications, RFID, over-the-horizon radar, automatic link establishment (ALE) / near-vertical incidence skywave (NVIS) radio communications, marine and mobile radio telephony

Very high frequency



30–300 MHz

10–1 m

FM, television broadcasts, line-of-sight ground-to-aircraft and aircraft-to-aircraft communications, land mobile and maritime mobile communications, amateur radio, weather radio

Ultra high frequency



300–3,000 MHz

1–0.1 m

Television broadcasts, microwave oven, microwave devices/communications, radio astronomy, mobile phones, wireless LAN, Bluetooth, ZigBee, GPS and two-way radios such as land mobile, FRS and GMRS radios, amateur radio, satellite radio, Remote control Systems, ADSB

Super high frequency



3–30 GHz

100–10 mm

Radio astronomy, microwave devices/communications, wireless LAN, DSRC, most modern radars, communications satellites, cable and satellite television broadcasting, DBS, amateur radio, satellite radio

Extremely high frequency



30–300 GHz

10–1 mm

Radio astronomy, high-frequency microwave radio relay, microwave remote sensing, amateur radio, directed-energy weapon, millimeter wave scanner, wireless LAN (802.11ad)

Terahertz or Tremendously high frequency

THz or THF


300–3,000 GHz

1–0.1 mm

Experimental medical imaging to replace X-rays, ultrafast molecular dynamics, condensed-matter physics, terahertz time-domain spectroscopy, terahertz computing/communications, remote sensing

Of course, there is more to this ‘story’ and some other world-renowned organizations also had a hand in the matter. US Institute of Electrical and Electronic Engineers (IEEE) has been quite productive and made a very salient contribution by introducing further classification of microwave range. Thanks to IEEE the frequency bands in the microwave range are designated by letters. This classification has also become widely used standard for radar bands.


Frequency range

Explanation of meaning of letters


0.003 to 0.03 GHz

High Frequency


0.03 to 0.3 GHz

Very High Frequency


0.3 to 1 GHz

Ultra High Frequency


1 to 2 GHz

Long wave


2 to 4 GHz

Short wave


4 to 8 GHz

Compromise between S and X


8 to 12 GHz

Used in WW II for fire control, X for cross (as in crosshair). Exotic.


12 to 18 GHz



18 to 27 GHz

Kurz (German for “short”)


27 to 40 GHz



40 to 75 GHz


75 to 110 GHz

W follows V in the alphabet

mm or G

110 to 300 GHz​


This convention began around World War 2 with military designations for frequencies used in radar, which was the first application of microwaves. It happened so there are several incompatible naming systems for microwave bands, and even within a given system the exact frequency range designated by a letter may vary somewhat between different application areas.

Of course other high-profile organizations like EU, NATO, US ECM have also made their contributions by introducing their view on classification frequency designations. The table below provides a brief comparison between classification and shows the ‘overlap’ areas.

Radio frequency bands

Some of our customers often use various terms associated with radio frequency bands and RF terminology in general, especially with reference to our terahertz generators (THz sources). This calls for a brief description of the Waveguide frequency bands established as standard among experts.


Frequency range


Frequency range

R band

1.70 to 2.60 GHz

K band

18.0 to 26.5 GHz

D band

2.20 to 3.30 GHz

Ka band

26.5 to 40.0 GHz

S band

2.60 to 3.95 GHz

Q band

33 to 50 GHz

E band

3.30 to 4.90 GHz

U band

40 to 60 GHz

G band

3.95 to 5.85 GHz

V band

40 to 75 GHz

F band

4.90 to 7.05 GHz

E band

60 to 90 GHz

C band

5.85 to 8.20 GHz

W band

75 to 110 GHz

H band

7.05 to 10.10 GHz

F band

90 to 140 GHz

X band

8.2 to 12.4 GHz

D band

110 to 170 GHz

Ku band

12.4 to 18.0 GHz

Y band

325 to 500 GHz

Terasense can offer THz sources that fit into E band, W band, F band and D band. For further details please visit our web-page dedicated to THz generators.

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