L band

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L band
NATO L band
Frequency range 40–60 GHz
Wavelength range 7.5–5 mm
Related bands V band (IEEE) · EHF (ITU)
IEEE L band
Frequency range 1–2 GHz
Wavelength range 3–1.5 dm
Related bands D band (NATO) · SHF (ITU)
ITU Radio Band Numbers

1 2 3 4 5 6 7 8 9 10 11 12

ITU Radio Band Symbols

ELF SLF ULF VLF LF MF HF VHF UHF SHF EHF THF

NATO Radio bands

A B C D E F G H I J K L M

IEEE Radar bands

HF VHF UHF L S C X Ku K Ka V W mm

Television and radio bands

I II III IV V VI

L band refers to four different bands of the electromagnetic spectrum: 40 to 60 GHz (NATO), 1 to 2 GHz (IEEE), 1565 nm to 1625 nm (optical), and around 3.5 micrometres (infrared astronomy).

NATO L band[edit]

The NATO L band is the range of radio frequencies from 40 GHz to 60 GHz in the system of letter designations for frequency bands used by the NATO for electronic countermeasure (ECM) applications.[1][2] This is equivalent to wavelengths between 7.5 mm and 5 mm.

The NATO L is a subset of both the EHF band as defined by the ITU as well as the V band as defined by the IEEE.[3][4]

IEEE L band[edit]

Military use[edit]

In the United States and overseas territories, the L band is held by the military for telemetry, thereby forcing digital radio to in-band on-channel (IBOC) solutions. Digital Audio Broadcasting (DAB) is typically done in the 1452–1492-MHz range as in most of the world, but other countries also use VHF and UHF bands.

GNSS[edit]

The Global Positioning System carriers are in the L band, centered at 1176.45 MHz (L5), 1227.60 MHz (L2), 1381.05 MHz (L3), and 1575.42 MHz (L1) frequencies.

Telecommunications use[edit]

GSM mobile phones operate at 800–900 and 1800–1900 MHz. Iridium Satellite LLC phones use frequencies between 1616 and 1626.5 MHz[5] to communicate with the satellites. Inmarsat and LightSquared terminals use frequencies between 1525 and 1646.5 MHz to communicate with the satellites. Thuraya satellite phones use frequencies between 1525 and 1661 MHz to communicate with the satellites.

ADS-B[edit]

Aircrafts can use Automatic dependent surveillance-broadcast equipment at 1090 MHz to communicate position information to the ground as well as between them for traffic information and avoidance. The 1090 MHz frequency is also used by Mode S transponders, which ADS-B extends when operated at this frequency. ADS-B information can also be broadcast just outside the L band range at 978 MHz. ADS-B is not yet mandatory, except in parts of Australia above FL300 (30000 feet).

Amateur radio[edit]

The Radio Regulations of the International Telecommunication Union allow amateur radio operations in the frequency range 1,240 to 1,300 MHz, and amateur satellite up-links are allowed in the range 1,260 to 1,270 MHz. This is known as the 23-centimeter band by radio amateurs and the L-band by AMSAT.

Digital Audio Broadcasting (Earth Orbital)[edit]

WorldSpace satellite radio broadcasts in the 1467–1492 MHz L sub-band.

DAB L band usage[edit]

The following blocks are used for T-DAB (terrestrial) broadcasts:

Block Center Frequency
LA 1452.960 MHz
LB 1454.672 MHz
LC 1456.384 MHz
LD 1458.096 MHz
LE 1459.808 MHz
LF 1461.520 MHz
LG 1463.232 MHz
LH 1464.944 MHz
LI 1466.656 MHz
LJ 1468.368 MHz
LK 1470.080 MHz
LL 1471.792 MHz
LM 1473.504 MHz
LN 1475.216 MHz
LO 1476.928 MHz
LP 1478.640 MHz

The following blocks are used for S-DAB (satellite) broadcasts:

Block Center Frequency
LQ 1480.352 MHz
LR 1482.064 MHz
LS 1483.776 MHz
LT 1485.488 MHz
LU 1487.200 MHz
LV 1488.912 MHz
LW 1490.624 MHz

Note: Canada used slightly different central frequencies for L-band DAB before they shut their systems down, while in many European countries DAB is limited part of Band III due to television and mobile two way radio using the rest.

Physics issues relating to band use[edit]

The band also contains the hyperfine transition of neutral hydrogen (the hydrogen line, 1420 MHz), which is of great astronomical interest as a means of imaging the normally invisible neutral atomic hydrogen in interstellar space. Consequently parts of the L-band are protected radio astronomy allocations worldwide.

Optical communications L band[edit]

L band is also used in optical communications to refer to the wavelength range 1565 nm to 1625 nm.

Infrared astronomy[edit]

Atmospheric windows in the infrared. The L band is the transmission window centred on 3.5 micrometres

In infrared astronomy, the L band refers to an atmospheric transmission window centred on 3.5 micrometres (in the mid-infrared).

See also[edit]

References[edit]

  1. ^ Leonid A. Belov; Sergey M. Smolskiy; Victor N. Kochemasov (2012). Handbook of RF, Microwave, and Millimeter-Wave Components. Artech House. pp. 27–28. ISBN 978-1-60807-209-5. 
  2. ^ Norman Friedman (2006). The Naval Institute Guide to World Naval Weapon Systems. Naval Institute Press. pp. xiii–xiv. ISBN 978-1-55750-262-9. 
  3. ^ "V.431: Nomenclature of the frequency and wavelength bands used in telecommunications". ITU-R. 2006-01-04. Retrieved 2014-02-03. 
  4. ^ "521-2002 - IEEE Standard Letter Designations for Radar-Frequency Bands". IEEE. 2003-01-14. doi:10.1109/IEEESTD.2003.94224. Retrieved 2014-02-03. (subscription required (help)). 
  5. ^ http://www.fcc.gov/Bureaus/International/Orders/1995/da950131.txt