Ka band

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IEEE Ka band
Frequency range
26.5 – 40 GHz
Wavelength range
1.11 cm – 7.5 mm
Related bands
  • K (NATO)
  • SHF (ITU)

The Ka band ("kay-ay band") is a portion of the microwave part of the electromagnetic spectrum defined as frequencies in the range 26.5–40 gigahertz (GHz),[1] i.e. wavelengths from slightly over one centimeter down to 7.5 millimeters.[2] The band is called Ka, short for "K-above" because it is the upper part of the original 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 satellites, uplink in either the 27.5 GHz and 31 GHz bands,[3] and high-resolution, close-range targeting radars aboard military airplanes. Some frequencies in this radio band are used for vehicle speed detection by law enforcement.[4] The Kepler Mission uses this frequency range to downlink the scientific data collected by the space telescope.

The designation "Ka-band" is from Kurz-above, which stems from the German word "kurz" meaning short.[5]

In satellite communications, the Ka band allows higher bandwidth communication. It is used in the Inmarsat I-5 system[6] and will be used in the Iridium Next satellite series, as well as the James Webb Space Telescope. The Ka band is more susceptible to rain attenuation than is the Ku band, which in turn is more susceptible than the C band.[7]

The frequency is commonly used by cosmic microwave background experiments.

References[edit]

  1. ^ R. Ludwig, P. Bretchko, RF Circuit Design, Theory and Applications, Prentice Hall NJ, 2000.
  2. ^ "Basics of Space Flight Section I. The Environment of Space". 
  3. ^ "Ka Band". 
  4. ^ Elert, Glenn. "Frequency of a Police Radar Gun". 
  5. ^ http://www.itwissen.info/definition/lexikon/K-Band-K-band.html (german)
  6. ^ "Archived copy". Archived from the original on May 11, 2013. Retrieved August 6, 2013. 
  7. ^ Miller, Peter. "Ka-Band – the future of satellite communication?" (pdf). Retrieved 2016-07-06.