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Ka band

IEEE Ka band
Frequency range
27–40 GHz
Wavelength range
11.1–7.5 mm
Related bands
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 Ka band (pronounced as either "kay-ay band" or "ka band") is a portion of the microwave part of the electromagnetic spectrum. The designation "Ka-band" is from Kurz-above, which stems from the German word kurz, meaning "short".[1]

There is no standard definition of Ka-band. IEEE Standard letter designations for Radar Bands define the nominal frequency range for Ka band in the range 27–40 gigahertz (GHz) in Tables 1 and 2 of IEEE Standard 521[2] i.e. wavelengths from slightly over one centimeter down to 7.5 millimeters.[3] The ITU however approves Ka-band satellite networks in the 17.3-31 GHz frequency range,[4] with most Ka-band satellite networks having uplinks in the 27.5-31 GHz and downlinks in the 17.7-21.2 GHz range.[4]

The band is called Ka, short for "K-above" because it is the upper part of the original (now obsolete) NATO K band, which was split into three bands because of the presence of the atmospheric water vapor resonance peak at 22.24 GHz (1.35 cm), which made the center unusable for long range transmission. The 30/20 GHz band is used in communications satellite uplinks in either the 27.5 GHz or 31 GHz bands,[5] and in high-resolution, close-range targeting radars aboard military airplanes. Some frequencies in this radio band are used for vehicle speed detection by law enforcement.[6] The Kepler Mission used this frequency range to downlink the scientific data collected by the space telescope[7].This frequency is also used for remote sensing of clouds by radar, by both ground-based[8] or satellite[9] systems such as INCUS.

In satellite communications, the Ka band allows higher bandwidth communication.[10] It was first used in the experimental ACTS Gigabit Satellite Network, and is currently used for high-throughput satellite Internet access in geostationary orbit (GEO) by the Inmarsat I-5 system,[11] Kacific K-1 satellite,[12] the ViaSat 1, 2, and 3 satellites[13] among others; in low Earth orbit (LEO) by the SpaceX Starlink system[14] and the Iridium Next satellite series;[15] it is also used in medium Earth orbit (MEO) by the SES O3b system;[16] and the James Webb Space Telescope.[17]

Planned future satellite projects using the Ka-band include Amazon's Project Kuiper satellite internet constellation in LEO,[18] SES's multi-orbit satellite internet system of the SES-17 satellite in GEO (launched in October 2021; in position and fully operational in June 2022)[19] and the O3b mPOWER constellation in MEO (first two satellites launched December 2022, nine more 2023-2024, and starting service in Q3 2023).[20][21][22]

The Ka band is more susceptible to rain attenuation than is the Ku band, which in turn is more susceptible than the C band.[23][24] The frequency is commonly used by cosmic microwave background experiments. 5th generation mobile networks will also partially overlap with the Ka band (28, 38, and 60 GHz).[citation needed]

See also

  • Saorsat, Ireland satellite television on Ka band

References

  1. ^ "K-Band (in German)". www.itwissen.info.
  2. ^ IEEE Standard Letter Designations for Radar-Frequency Bands, IEEE, retrieved 2024-10-30
  3. ^ "Basics of Space Flight Section I. The Environment of Space".
  4. ^ a b Christensen, Jorn (September 2012). "ITU Regulations for Ka-band Satellite Networks" (PDF). ITU. Retrieved October 30, 2024.
  5. ^ "Ka Band". 6 April 2019.
  6. ^ Elert, Glenn. "Frequency of a Police Radar Gun".
  7. ^ Pham, Timothy; Liao, Jason (2016-09-13). "Characterization of Operational Performance of Ka-Band Links in Deep Space Network". {{cite journal}}: Cite journal requires |journal= (help)
  8. ^ https://amof.ac.uk/instruments/mobile-cloud-radar/
  9. ^ https://incus.colostate.edu/mission/mission-instruments
  10. ^ L/Ku/Ka-band satellites – what does it all mean? Archived 2021-04-30 at the Wayback Machine Get Connected. 11 September 2017. Accessed 27 April 2021
  11. ^ "Inmarsat - Inmarsat Announces $1.2bn Investment in Next Generation Ka-Band Satellite Network - Press Release". Archived from the original on May 11, 2013. Retrieved August 6, 2013.
  12. ^ "Technology". Kacific. Retrieved 2024-10-30.
  13. ^ "Satellite fleet". Viasat.com. Retrieved 2024-10-30.
  14. ^ "SpaceX seeks FCC permission for operating all first-gen Starlink in lower orbit". SpaceNews.com. 2020-04-21. Retrieved 2020-04-23.
  15. ^ Iridium-NEXT Gunter's Space Page. Accessed 28 April 2021
  16. ^ Four New Satellites Ride Into Space To Join Growing SES Constellation Space.com 4 April 2019. Accessed 28 April 2021
  17. ^ James Webb Space Telescope User Documentation - JWST Communications Subsystem Space Terlescope Science Institute. Accessed 28 April 2021
  18. ^ Foust, Jeff (15 December 2020). "Amazon unveils flat-panel customer terminal for Kuiper constellation". SpaceNews. Retrieved 29 December 2020.
  19. ^ SES-17 Ka-Band Satellite is Now Operational Via Satellite. 16 June 2022. Accessed 27 June 2022
  20. ^ SES’ Satellites’ Agility Achieved With ARC and Kythera Space Solutions SatNews. 24 November 2020. Accessed 28 April 2021
  21. ^ "SES YTD 2021 Results" (PDF). SES. 4 November 2021. p. 4. Retrieved 27 January 2022.
  22. ^ SpaceX launches first pair of O3b mPower satellites SpaceNews. 16 December 2022. Accessed 27 December 2022
  23. ^ Suquet, Étienne; Monvoisin, Jean‐Pascal; Castanet, Laurent; Féral, Laurent; Boulanger, Xavier (March 2024). "Twelve years of rain attenuation statistics of Earth–space propagation experiment at Ka band in Toulouse". International Journal of Satellite Communications and Networking. 42 (2): 165–180. doi:10.1002/sat.1505. ISSN 1542-0973.
  24. ^ "The impact of weather on Ka-band frequencies - Room: The Space Journal". Room The Space Journal of Asgardia. Retrieved 2024-10-30.
Quelle: http://en.wikipedia.org/wiki/Ka_band