Ku band

The Ku band (/ˌkeɪˈjuː/) is the portion of the electromagnetic spectrum in the microwave range of frequencies from 12 to 18 gigahertz (GHz).

The symbol is short for "K-under" (originally German: Kurz-unten), because it is the lower part of the original NATO K band, which was split into three bands (Ku, K, and Ka) 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 band is split by the International Telecommunication Union (ITU) into multiple segments that vary by geographical region.

NBC was the first television network to uplink a majority of its affiliate feeds via Ku band in 1983.

Some frequencies in this radio band are employed in radar guns used by law enforcement to detect vehicles speeding, especially in Europe.

BSS (DBS direct broadcast satellites) normally carry 16 to 32 transponders of 27 MHz bandwidth running at 100 to 240 watts of power, allowing the use of receiver antennas as small as 18 inches (450 mm).

Measurements of rain attenuation in Indonesia have been done for satellite communication links in Padang, Cibinong, Surabaya and Bandung.

NSS 6, launched in December 2002 and positioned at 95° East, contains only Ku-band transponders with a footprint on Indonesia (Sumatra, Java, Borneo, Celebes, Bali, Nusa Tenggara, Moluccas).

Other satellites that provides Ku band covers Indonesia are MEASAT-3b, JCSAT-4B, AsiaSat 5, ST-2, Chinasat 11, Koreasat 8/ABS-2, SES-8, Telkom-3S, and Nusantara Satu.

As power levels on both C and Ku band satellites have increased over the years, dish beam-width has become much more critical than gain.

For the end users Ku band is generally cheaper and enables smaller antennas (both because of the higher frequency and a more focused beam).

It is due to snow or ice accumulation on a dish significantly altering its focal point.