Instructions
Use the slider at the bottom of the screen to learn more
about the radio bands that make up this part of the spectrum
Very low frequency (VLF)
3 kHz – 30 kHz
10 km – 100 km
Uses
This band is not used much for communications in general, because of the difficulties in building efficient antennas for the long wavelengths involved (10–100 km).
Radio waves at these frequencies, or lower, have the ability to penetrate sea water to an extent, so this band is used for submarine communications.
The VLF band has been used for global navigation systems with ground-based transmitters.
Propagation
Surface wave.
Low frequency (LF)
30 kHz – 300 kHz
1 km – 10 km
Uses
This band is involved in long-wave radio broadcasting using amplitude modulation (AM). Surface wave propagation is effective at these frequencies, allowing coverage of a large region with one high-power transmitter. The bandwidth available at LF is limited, though (only 270 kHz altogether). Also, a large land area is needed for an effective broadcast transmitting antenna at these long wavelengths.
Navigation systems using ground-based transmitters operate in the LF band. They provide a backup to satellite-based systems such as GPS, which operates in the UHF band.
The LF band is used in some territories for broadcasting time signals.
Propagation
Mainly surface wave.
Medium frequency (MF)
300 kHz – 3 MHz
100 m – 1 km
Uses
This band is involved in medium-wave radio broadcasting using amplitude modulation (AM). The reception range is increased at night time by sky-wave propagation; while this allows more stations to be received, it can also result in interference from unwanted transmissions. The transmitting antenna may be a quarter-wavelength monopole.
Propagation
Surface wave. Sky wave at night time.
High frequency (HF)
3 MHz – 30 MHz
10 m – 100 m
Uses
This band is used for amateur radio; global distances can be covered by sky-wave propagation, often with modest transmitter power.
Propagation at HF is highly dependent on the state of the ionosphere. Nonetheless, the HF band is used for short-wave radio broadcasting, and also for a variety of government, military, aviation and maritime purposes.
Propagation
Sky wave.
Very high frequency (VHF)
30 MHz – 300 MHz
1 m – 10 m
Uses
The frequency range of VHF allows wider-bandwidth services to be accommodated than is possible at HF, MF or LF. The shorter wavelength of VHF compared to HF also means that antennas are more compact. These features make the VHF band attractive for a wide variety of services. FM radio and DAB radio, which require higher bandwidths than the AM transmissions at MF and LF, are situated in this band. The band is also used for aviation, and for some private mobile radio (e.g. taxi services).
Propagation
Line of sight, together with contributions from reflected, diffracted and scattered waves.
Ultra high frequency (UHF)
300 MHz – 3 GHz
100 mm – 1 m
Uses
This band affords more spectrum bandwidth than VHF, so terrestrial TV broadcasting in the UK is done at UHF (though VHF was used in the days before UHF receivers were widely available, and fewer channels were broadcast). Some (not all) channels of 8 MHz bandwidth in the range 470–790 MHz are used, each channel carrying a digital multiplex.
The relatively short wavelengths at UHF mean that antennas can be compact enough to fit into small mobile devices. The propagation characteristics of this band are favourable for short- to medium-range links, and the technology is mature. So it is not surprising that a huge variety of applications are found in this band, including mobile phones (at 800 MHz, 900 MHz, 1.8 GHz, 2.1 GHz and 2.6 GHz), WiFi (at 2.4 GHz), Bluetooth, GPS, cordless phones and baby monitors. Some radar applications also operate here.
Microwave ovens work at a frequency of 2.45 GHz, which is within this band.
Propagation
Line of sight, together with contributions from reflected, diffracted and scattered waves.
Super high frequency (SHF)
3 GHz – 30 GHz
10 mm – 100 mm
Uses
Satellite broadcasting operates in this band, where it is able to take advantage of the wider bandwidths that are available for allocation, compared to UHF and lower bands. Atmospheric absorption is relatively low compared to that in the next frequency band (EHF).
Congestion in the UHF spectrum has also encouraged a move to higher frequencies for wireless networking, in particular the 5 GHz WiFi standard.
The SHF band is used by many radar applications.
Propagation
Line of sight, together with contributions from reflected, diffracted and scattered waves.
Extremely high frequency (EHF)
30 GHz – 300 GHz
1 mm – 10 mm
Uses
This band is important for specialised uses such as radio astronomy and satellite exploration.
In the past the EHF band was not used much for general communications, owing to the technical challenges of transmitter and receiver design at these frequencies. However, this is changing, with 60 GHz proposed as a WiFi band for short-range data communication. This particular frequency is not suitable for long-range terrestrial communication because of a peak in atmospheric absorption.
Propagation
Line of sight. Atmospheric absorption is strong, particularly at 60 GHz and 200 GHz.