Radio spectrum

Source: Wikipedia, the free encyclopedia.
This article is about the spectral band. For the radiation, see radio wave. For the frequency, see radio frequency. For the broadcaster, see Spectrum Radio.
Radio bands
ITU
1 (ELF) 2 (SLF) 3 (ULF) 4 (VLF)
5 (LF) 6 (MF) 7 (HF) 8 (VHF)
9 (UHF) 10 (SHF) 11 (EHF) 12 (THF)
EU / NATO / US ECM
IEEE
Other TV and radio

The radio spectrum is the part of the

transmission of radio waves is strictly regulated by national laws, coordinated by an international body, the International Telecommunication Union (ITU).[1]

Different parts of the radio spectrum are allocated by the ITU for different radio transmission technologies and applications; some 40

frequency reuse, dynamic spectrum management, frequency pooling, and cognitive radio
.

Limits

The

electromagnetic waves, there is no lower limit to the frequency of radio waves.[4]
Radio waves are defined by the ITU as: "electromagnetic waves of frequencies arbitrarily lower than 3000 GHz, propagated in space without artificial guide".
terahertz band, from 300 gigahertz to 3 terahertz, can be considered either as microwaves or infrared. It is the highest band categorized as radio waves by the International Telecommunication Union.[4] but spectroscopic scientists consider these frequencies part of the far infrared
and mid infrared bands.

Because it is a fixed resource, the practical limits and basic physical considerations of the radio spectrum, the frequencies which are useful for radio communication, are determined by technological limitations which are impossible to overcome.[6] So although the radio spectrum is becoming increasingly congested, there is no possible way to add additional frequency bandwidth outside of that currently in use.[6] The lowest frequencies used for radio communication are limited by the increasing size of transmitting antennas required.[6] The size of antenna required to radiate radio power efficiently increases in proportion to wavelength or inversely with frequency. Below about 10 kHz (a wavelength of 30 km), elevated wire antennas kilometers in diameter are required, so very few radio systems use frequencies below this. A second limit is the decreasing bandwidth available at low frequencies, which limits the data rate that can be transmitted.[6] Below about 30 kHz, audio modulation is impractical and only slow baud rate data communication is used. The lowest frequencies that have been used for radio communication are around 80 Hz, in ELF submarine communications systems built by a few nations' navies to communicate with their submerged submarines hundreds of meters underwater. These employ huge ground dipole antennas 20–60 km long excited by megawatts of transmitter power, and transmit data at an extremely slow rate of about 1 bit per minute (17 millibits per second, or about 5 minutes per character).

The highest frequencies useful for radio communication are limited by the absorption of microwave energy by the atmosphere.

visible light ranges.[7][8]

Bands

For broader coverage of this topic, see
EM band
.

A radio band is a small

frequency band (a contiguous section of the range of the radio spectrum) in which channels
are usually used or set aside for the same purpose. To prevent interference and allow for efficient use of the radio spectrum, similar services are allocated in bands. For example, broadcasting, mobile radio, or navigation devices, will be allocated in non-overlapping ranges of frequencies.

Band plan

For each radio band, the ITU has a band plan (or frequency plan) which dictates how it is to be used and shared, to avoid

receivers.[9]

Each frequency plan defines the frequency range to be included, how channels are to be defined, and what will be carried on those channels. Typical definitions set forth in a frequency plan are:

ITU

The actual authorized frequency bands are defined by the

ITU[10] and the local regulating agencies like the US Federal Communications Commission (FCC) [11] and voluntary best practices help avoid interference.[12]

As a matter of convention, the ITU divides the radio spectrum into 12 bands, each beginning at a

Earth's atmosphere is so great that the atmosphere is effectively opaque, until it becomes transparent again in the near-infrared and optical window
frequency ranges.

These ITU radio bands are defined in the

Radio Regulations. Article 2, provision No. 2.1 states that "the radio spectrum shall be subdivided into nine frequency bands, which shall be designated by progressive whole numbers in accordance with the following table".[13]

The table originated with a recommendation of the fourth

CCIR meeting, held in Bucharest in 1937, and was approved by the International Radio Conference held at Atlantic City, NJ in 1947. The idea to give each band a number, in which the number is the logarithm of the approximate geometric mean of the upper and lower band limits in Hz, originated with B. C. Fleming-Williams, who suggested it in a letter to the editor of Wireless Engineer in 1942. For example, the approximate geometric mean of band 7 is 10 MHz, or 107 Hz.[14]

The band name "tremendously low frequency" (TLF) has been used for frequencies from 1–3 Hz (wavelengths from 300,000–100,000 km),[15] but the term has not been defined by the ITU.[16]

Band name Abbreviation ITU band number Frequency and wavelength Example uses
Extremely low frequency ELF 1 3–30 Hz
100,000–10,000 km		 Communication with submarines
Super low frequency SLF 2 30–300 Hz
10,000–1,000 km		 Communication with submarines
Ultra low frequency ULF 3 300–3,000 Hz
1,000–100 km		 Communication with submarines,
communication within mines, landline telephony, fax machines, fiber-optic communication
Very low frequency VLF 4 3–30 kHz
100–10 km		 Navigation, time signals, communication with submarines, landline telephony, wireless heart rate monitors, geophysics
Low frequency LF 5 30–300 kHz
10–1 km		 Navigation,
RFID, amateur radio
.
Medium frequency MF 6 300–3,000 kHz
1,000–100 m
dial-up internet
.
High frequency HF 7 3–30 MHz
100–10 m
cordless phones
.
Very high frequency VHF 8 30–300 MHz
10–1 m
cordless phones
.
Ultra high frequency UHF 9 300–3,000 MHz
100–10 cm		 Television broadcasts, cable television broadcasting,
dial-up internet, satellite broadcasting, communication satellites, weather satellites, satellite phones (L band), satellite phones (S band
).
Super high frequency SHF 10 3–30 GHz
10–1 cm		 Radio astronomy, microwave devices/communications, wireless LAN,
cordless phones, internet
, satellite phones (S band).
Extremely high frequency EHF 11 30–300 GHz
10–1 mm		 Radio astronomy, satellite broadcasting, communication satellites, weather satellites, high-frequency
microwave radio relay, microwave remote sensing, directed-energy weapon, millimeter wave scanner, Wireless Lan 802.11ad
, internet.
tremendously high frequency
 THF 12 300–3,000 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

IEEE radar bands

Frequency bands in the microwave range are designated by letters. This convention began around World War II with military designations for frequencies used in radar, which was the first application of microwaves. Unfortunately, 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. One widely used standard is the IEEE radar bands established by the US Institute of Electrical and Electronics Engineers.

Radar-frequency bands according to
IEEE standard[17]
Band
designation		 Frequency range Explanation of meaning of letters
HF 0.003 to 0.03 GHz High frequency[18]
VHF 0.03 to 0.3 GHz Very high frequency[18]
UHF 0.3 to 1 GHz Ultra-high frequency[18]
L 1 to 2 GHz Long wave
S 2 to 4 GHz Short wave
C 4 to 8 GHz Compromise between S and X
X 8 to 12 GHz Used in World War II for
crosshair). Exotic.[19]
Ku 12 to 18 GHz Kurz-under
K 18 to 27 GHz German: Kurz (short)
Ka 27 to 40 GHz Kurz-above
V 40 to 75 GHz
W 75 to 110 GHz W follows V in the alphabet[20]
G
 110 to 300 GHz[note 1] Millimeter[17]
  1. ^ The designation mm is also used to refer to the range from 30 to 300 GHz.[17]

EU, NATO, US ECM frequency designations

NATO letter band designation[21][19][22] Broadcasting
band
designation
New nomenclature Old nomenclature
Band Frequency (
MHz
)		 Band Frequency (MHz)
A 0 – 250 I 100 – 150 Band I
47 – 68 MHz (TV)
Band II
87.5 – 108 MHz (FM)
G 150 – 225 Band III
174 – 230 MHz (TV)
B 250 – 500 P 225 – 390
C 500 – 1 000 L 390 – 1 550 Band IV
470 – 582 MHz (TV)
Band V
582 – 862 MHz (TV)
D 1 000 – 2 000 S 1 550 – 3 900
E 2 000 – 3 000
F 3 000 – 4 000
G 4 000 – 6 000 C 3 900 – 6 200
H 6 000 – 8 000 X 6 200 – 10 900
I 8 000 – 10 000
J 10 000 – 20 000 Ku 10 900 – 20 000
K 20 000 – 40 000 Ka 20 000 – 36 000
L 40 000 – 60 000 Q 36 000 – 46 000
V 46 000 – 56 000
M 60 000 – 100 000 W 56 000 – 100 000
US Military/
SACLANT
N 100 000 – 200 000
O 100 000 – 200 000

Waveguide frequency bands

See also:
Waveguide (electromagnetism) § In practice
Band Frequency range [23]
R band
 1.70 to 2.60 GHz
D band 2.20 to 3.30 GHz
S band 2.60 to 3.95 GHz
E band 3.30 to 4.90 GHz
G band 3.95 to 5.85 GHz
F band 4.90 to 7.05 GHz
C band 5.85 to 8.20 GHz
H band 7.05 to 10.10 GHz
X band 8.2 to 12.4 GHz
Ku band 12.4 to 18.0 GHz
K band 18.0 to 26.5 GHz
Ka band 26.5 to 40.0 GHz
Q band 33 to 50 GHz
U band 40 to 60 GHz
V band 50 to 75 GHz
E band 60 to 90 GHz
W band 75 to 110 GHz
F band 90 to 140 GHz
D band 110 to 170 GHz
Y band
 325 to 500 GHz

Comparison of radio band designation standards

Comparison of frequency band designations

The frequencies from 1–3 Hz (wavelengths from 300,000–100,000 km) have been known by the band name "tremendously low frequency" (TLF) ,[15] but the term has not been defined by the ITU.[24]

Frequency IEEE[17] EU,
NATO,
US ECM 		ITU
no. abbr.
A
  
3 Hz 1 ELF
30 Hz 2 SLF
300 Hz 3 ULF
3 kHz 4 VLF
30 kHz 5 LF
300 kHz 6 MF
3 MHz HF 7 HF
30 MHz VHF 8 VHF
250 MHz
B
300 MHz UHF 9 UHF
500 MHz C
1 GHz L D
2 GHz S E
3 GHz F 10 SHF
4 GHz C G
6 GHz H
8 GHz X I
10 GHz J
12 GHz Ku
18 GHz K
20 GHz K
27 GHz Ka
30 GHz 11 EHF
40 GHz V L
60 GHz M
75 GHz W
100 GHz
110 GHz
mm
300 GHz
12
THF
3 THz  

Applications

See also: Radio § Applications

Broadcasting

Main article: Radio broadcasting

Broadcast frequencies:

Designations for television and FM radio broadcast frequencies vary between countries, see

cellular phone and various land mobile communications systems. Even within the allocation still dedicated to television, TV-band devices
use channels without local broadcasters.

The Apex band in the United States was a pre-WWII allocation for VHF audio broadcasting; it was made obsolete after the introduction of FM broadcasting.

Air band

Airband refers to VHF frequencies 108 to 137 MHz, used for navigation and voice communication with aircraft. Trans-oceanic aircraft also carry HF radio and satellite transceivers.

Marine band

The greatest incentive for development of radio was the need to communicate with ships out of visual range of shore. From the very early days of radio, large oceangoing vessels carried powerful long-wave and medium-wave transmitters. High-frequency allocations are still designated for ships, although satellite systems have taken over some of the safety applications previously served by 500 kHz and other frequencies. 2182 kHz is a medium-wave frequency still used for marine emergency communication.

Marine VHF radio is used in coastal waters and relatively short-range communication between vessels and to shore stations. Radios are channelized, with different channels used for different purposes; marine Channel 16 is used for calling and emergencies.

Amateur radio frequencies

UHF
parts of the radio spectrum.

Citizens' band and personal radio services

Citizens' band radio is allocated in many countries, using channelized radios in the upper HF part of the spectrum (around 27 MHz). It is used for personal, small business and hobby purposes. Other frequency allocations are used for similar services in different jurisdictions, for example UHF CB is allocated in Australia. A wide range of personal radio services
exist around the world, usually emphasizing short-range communication between individuals or for small businesses, simplified license requirements or in some countries covered by a class license, and usually FM transceivers using around 1 watt or less.

Industrial, scientific, medical

The

ISM bands were initially reserved for non-communications uses of RF energy, such as microwave ovens, radio-frequency heating, and similar purposes. However, in recent years the largest use of these bands has been by short-range low-power communications systems, since users do not have to hold a radio operator's license. Cordless telephones, wireless computer networks, Bluetooth devices, and garage door openers
all use the ISM bands. ISM devices do not have regulatory protection against interference from other users of the band.

Land mobile bands

Bands of frequencies, especially in the VHF and UHF parts of the spectrum, are allocated for communication between fixed

land mobile vehicle-mounted or portable transceivers. In the United States these services are informally known as business band radio. See also Professional mobile radio
.

Police radio and other public safety services such as fire departments and ambulances are generally found in the VHF and UHF parts of the spectrum. Trunking systems are often used to make most efficient use of the limited number of frequencies available.

The demand for mobile telephone service has led to large blocks of radio spectrum allocated to cellular frequencies.

Radio control

Reliable

unlicensed spectrum in the 27 MHz or 49 MHz bands, but more costly aircraft, boat, or land vehicle models use dedicated radio control
frequencies near 72 MHz to avoid interference by unlicensed uses. The 21st century has seen a move to 2.4 GHz spread spectrum RC control systems.

Licensed amateur radio operators use portions of the 6-meter band in North America. Industrial remote control of cranes or railway locomotives use assigned frequencies that vary by area.

Radar

Radar applications use relatively high power pulse transmitters and sensitive receivers, so radar is operated on bands not used for other purposes. Most radar bands are in the microwave part of the spectrum, although certain important applications for meteorology make use of powerful transmitters in the UHF band.

See also

Notes

  1. ^ ITU Radio Regulations – Article 1, Definitions of Radio Services, Article 1.2 Administration: Any governmental department or service responsible for discharging the obligations undertaken in the Constitution of the International Telecommunication Union, in the Convention of the International Telecommunication Union and in the Administrative Regulations (CS 1002)
  2. ^ International Telecommunication Union's Radio Regulations, Edition of 2020.
  3. ISBN 978-1-84376-230-0. Archived
    from the original on 2022-04-07. Retrieved 2020-11-02.
  4. ^ a b Radio waves are defined by the ITU as: "electromagnetic waves of frequencies arbitrarily lower than 3000 GHz, propagated in space without artificial guide", Radio Regulations, 2020 Edition. International Telecommunication Union. Archived from the original on 2022-02-18. Retrieved 2022-02-18.
  5. ^ Radio Regulations, 2020 Edition. International Telecommunication Union. Archived from the original on 2022-02-18. Retrieved 2022-02-18.
  6. ^
    ISBN 9780750637404. Archived
    from the original on 2022-04-07. Retrieved 2019-11-25.
  7. ISBN 9781351356367. Archived
    from the original on 2023-02-21. Retrieved 2021-05-20.
  8. ^ Siegel, Peter (2002). "Studying the Energy of the Universe". Education materials. NASA website. Archived from the original on 20 June 2021. Retrieved 19 May 2021.
  9. ^ See detail of bands: [1] Archived 2014-07-03 at the Wayback Machine
  10. ^ Frequency Plans
  11. ^ For the authorized frequency bands for amateur radio use see: Authorized frequency bands
  12. ^ US ARRL Amateur Radio Bands and power limits Graphical Frequency Allocations
  13. ^ ITU Radio Regulations, Volume 1, Article 2; Edition of 2020. Available online at "Article 2.1: Frequency and wavelength bands" (PDF). Radio Regulations 2016 Edition. International Telecommunication Union. 1 January 2017. Archived from the original on 18 February 2022. Retrieved 18 February 2020.
  14. ^ Booth, C. F. (1949). "Nomenclature of Frequencies". The Post Office Electrical Engineers' Journal. 42 (1): 47–48.
  15. ^
    ISBN 978-3-030-71050-7
    .
  16. ^ "Nomenclature of the frequency and wavelength bands used in telecommunications" (PDF). International Telecommunications Union. Geneva, Switzerland: International Telecommunications Union. 2015. Retrieved 7 April 2023.
  17. ^ a b c d e IEEE Std 521-2002 Standard Letter Designations for Radar-Frequency Bands Archived 2013-12-21 at the Wayback Machine.
  18. ^ a b c Table 2 in [17]
  19. ^
    ISBN 978-1-55750-262-9. Archived
    from the original on 2023-02-21. Retrieved 2016-10-13.
  20. ISSN 1751-8636
    .
  21. ISBN 978-1-60807-209-5
    .
  22. ^ NATO Allied Radio Frequency Agency (ARFA) HANDBOOK – VOLUME I; PART IV – APPENDICES, ... G-2, ... NOMENCLATURE OF THE FREQUENCY AND WAVELENGTH BANDS USED IN RADIOCOMMUNCATION.
  23. ^ "www.microwaves101.com "Waveguide frequency bands and interior dimensions"". Archived from the original on 2008-02-08. Retrieved 2009-11-16.
  24. ^ "Nomenclature of the frequency and wavelength bands used in telecommunications" (PDF). International Telecommunications Union. Geneva, Switzerland: International Telecommunications Union. 2015. Retrieved 7 April 2023.

References

External links

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