Ka band

The K_a band ("kay-ay band") covers the frequencies of 26.5–40 GHz,^[1] i.e. wavelengths from slightly over one centimeter down to 7.5 millimeters.^[2] The K_a band is part of the K band of the microwave band of the electromagnetic spectrum. This symbol refers to "K-above": in other words, the band directly above the K-band. 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] Kepler Mission uses this frequency range to downlink the scientific data collected by the space telescope.

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

In satellite communications, the K_a band allows higher bandwidth communication. It is used in the Inmarsat I-5 system^[6] and will be used in the upcoming Newsat Jabiru,^[7] and Iridium Next satellite series, for instance. The K_a band is more susceptible to rain attenuation than is the K_u band, which in turn is more susceptible than the C band.^[8]

References

1. ↑ R. Ludwig, P. Bretchko, RF Circuit Design, Theory and Applications, Prentice Hall NJ, 2000.
2. ↑ "Basics of Space Flight: Electromagnetic Phenomena."
3. ↑ http://www.tech-faq.com/ka-band.shtml
4. ↑ http://hypertextbook.com/facts/2000/MaxLipkin.shtml
5. ↑ http://www.itwissen.info/definition/lexikon/K-Band-K-band.html (german)
6. ↑ http://www.inmarsat.com/corporate/media-centre/press-releases/inmarsat-announces-1.2bn-investment-in-next-generation-ka-band-satellite-network
7. ↑ http://www.newsat.com/Satellites/kaband.html
8. ↑ http://www.tele-satellite.com/TELE-satellite-0709/eng/feature.pdf