Ka and Ku-Band

Just to refresh our memory regarding electromagnetic spectrum :-D


Wikipedia

The IEEE K band is a portion of the electromagnetic spectrum in the microwave range of frequencies ranging between 18 and 27 GHz. K band between 18 and 26.5 GHz is absorbed easily by water vapor (H2O resonance peak at 22.24 GHz, 1.35 cm).

The IEEE K band is conventionally divided into three sub-bands:

• Ka band: K-above band, 26.5–40 GHz, mainly used for radar and experimental communications.
• K-band 18-27 GHz
• Ku band: K-under band, 12–18 GHz, mainly used for satellite communications, terrestrial microwave communications, and radar, especially police traffic-speed detectors

The Ka band covers the frequencies of 26.5-40GHz. The Ka 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 so-called 30/20 GHz band is used in communications satellites, uplink in either the 27.5 GHz and 31 GHz bands, 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.

The Ku band is a portion of the electromagnetic spectrum in the microwave range of frequencies. This symbol refers to "K-under"—in other words, the band directly below the K-band. In radar applications, it ranges from 12 to 18 GHz according to the formal definition of radar frequency band nomenclature in IEEE Standard 521-2002.

Ku band is primarily used for satellite communications, most notably NASA's Tracking Data Relay Satellite used for both space shuttle and ISS communications. Ku band satellites are also used for backhauls and particularly for satellite from remote locations back to a television network's studio for editing and broadcasting. The band is split into multiple segments that vary by geographical region by the International Telecommunication Union (ITU). NBC was the first television network to uplink a majority of its affiliate feeds via Ku band in 1983.

Indonesia
The ITU has categorized Indonesia as Region P, countries with very high rain precipitation. This statement has made many people unsure about using Ku-band (11 – 18 GHz) in Indonesia. If frequencies higher than 10 GHz are used in a heavy rain area, a decrease in communication availability results. This problem can be solved by using an appropriate link budget when designing the wireless communication link. Higher power can overcome the loss to rain fade.

Measurements of rain attenuation in Indonesia have been done for satellite communication links in Padang, Cibinong, Surabaya and Bandung. The DAH Model for rain attenuation prediction is valid for Indonesia, in addition to the ITU model. The DAH model has become an ITU recommendation since 2001 (Recommendation No. ITU-R P.618-7). This model can create a 99.7% available link so that Ku-band can be applied in Indonesia.

The use of the Ku-band for satellite communications in tropical regions like Indonesia is becoming more frequent. Several satellites above Indonesia have Ku-band transponders, and even Ka-band transponders. Newskies (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). The iPSTAR satellite, launched in 2004 also uses Ku band footprints. MEASAT has named the Ku-band footprint directed towards Indonesia Ku-band for Indonesi. MEASAT-3 plans to cover the whole of Indonesia from West to East. This satellite was launched by Malaysia in December 2006.