Ku band
Encyclopedia
The Kμ band (ˌkeɪˈjuː) is a portion of the electromagnetic spectrum
in the microwave
range of frequencies. This symbol refers to (originally )—in other words, the band directly below the K-band. In radar applications, it ranges from 12-18 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 for fixed and broadcast services, and for specific applications such as 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.
Some frequencies in this radio band are used for vehicle speed detection by law enforcement, especially in Europe.
2 from 11.7 to 12.2 GHz (Local Oscillator
Frequency (LOF) 10.750 GHz), allocated to the FSS (fixed service satellite
), uplink
from 14.0 to 14.5 GHz. There are more than 22 FSS Ku band satellites orbiting over North America, each carrying 12 to 48 transponders
, 20 to 120 watt
s per transponder, and requiring a 0.8-m to 1.5-m antenna for clear reception.
The 12.2 to 12.7 GHz (LOF 11.250 GHz) segment is allocated to the BSS (broadcasting satellite service). BSS (DBS direct broadcast satellite
s) 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).
14.0 to 14.5 GHz). In Europe Ku band is used from 10.7 to 12.75 GHz (LOF Low 9.750 GHz, LOF High 10.600 GHz) for direct broadcast satellite
services such as those carried by the Astra
satellites. The 11.7 to 12.5 GHz segment is allocated to the BSS (broadcasting satellite service).
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 transponder
s, 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.
, and radionavigation. However, not all of these services are actually operating in this band and others are only minor users.
The Ku band also offers a user more flexibility. A smaller dish size and a Ku band system's freedom from terrestrial operations simplifies finding a suitable dish site. For the end users Ku band is generally cheaper and enables smaller antennas (both because of the higher frequency and a more focused beam). Ku band is also less vulnerable to rain fade than the Ka band frequency spectrum.
The satellite operator's Earth Station antenna do require more accurate position control when operating at Ku band than compared to C band. Position feedback accuracies are higher and the antenna may require a closed loop control system to maintain position under wind loading of the dish surface.
"). This problem can be mitigated, however, by deploying an appropriate link budget strategy when designing the satellite network, and allocating a higher power consumption to compensate rain fade loss. The Ku band is not only used for television transmission, which some sources imply, but also very much for digital data transmission via satellites, and for voice/audio transmissions.
The higher frequency spectrum of the Ku band is particularly susceptible to signal degradation, considerably more so than C-band satellite frequency spectrum. A similar phenomenon, called "snow fade" (where snow or ice accumulation significantly alters the focal point of a dish) can also occur during winter precipitation. Also, the Ku band satellites typically require considerably more power to transmit than the C-band satellites. Under both "rain fade
" and "snow fade" conditions, Ka and Ku band losses can be marginally reduced using super-hydrophobic Lotus effect
coatings.
(RSGB), are shown in the table below:
Footnote: P band is sometimes incorrectly used for Ku Band. "P" for "previous" was a radar band used in the UK ranging from 250 to 500 MHz and now obsolete per IEEE Std 521, see http://www.radioing.com/eengineer/bands.html and http://www.microwaves101.com/encyclopedia/letterbands.cfm. For other definitions see Letter Designations of Microwave Bands
Electromagnetic spectrum
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object....
in the microwave
Microwave
Microwaves, a subset of radio waves, have wavelengths ranging from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz and 300 GHz. This broad definition includes both UHF and EHF , and various sources use different boundaries...
range of frequencies. This symbol refers to (originally )—in other words, the band directly below the K-band. In radar applications, it ranges from 12-18 GHz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
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 for fixed and broadcast services, and for specific applications such as NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
's Tracking Data Relay Satellite used for both space shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
and ISS communications. Ku band satellites are also used for backhauls and particularly for satellite from remote locations back to a television
Television
Television is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
network's studio for editing and broadcasting
Broadcasting
Broadcasting is the distribution of audio and video content to a dispersed audience via any audio visual medium. Receiving parties may include the general public or a relatively large subset of thereof...
. The band is split into multiple segments that vary by geographical region by the International Telecommunication Union
International Telecommunication Union
The International Telecommunication Union is the specialized agency of the United Nations which is responsible for information and communication technologies...
(ITU). NBC
NBC
The National Broadcasting Company is an American commercial broadcasting television network and former radio network headquartered in the GE Building in New York City's Rockefeller Center with additional major offices near Los Angeles and in Chicago...
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 used for vehicle speed detection by law enforcement, especially in Europe.
The Americas
Segments in most of The Americas are represented by ITU RegionITU region
The International Telecommunication Union , in its International Radio Regulations, divides the world into three ITU regions for the purposes of managing the global radio spectrum...
2 from 11.7 to 12.2 GHz (Local Oscillator
Local oscillator
A local oscillator is an electronic device used to generate a signal normally for the purpose of converting a signal of interest to a different frequency using a mixer. This process of frequency conversion, also referred to as heterodyning, produces the sum and difference frequencies of the...
Frequency (LOF) 10.750 GHz), allocated to the FSS (fixed service satellite
Fixed Service Satellite
Fixed Service Satellite , is the official classification for geostationary communications satellites used for broadcast feeds for television stations and radio stations and broadcast networks, as well as for telephony, telecommunications and data communications.FSS satellites have also been used...
), uplink
Uplink
A telecommunications link is generally one of several types of information transmission paths such as those provided by communication satellites to connect two points on earth.-Uplink:...
from 14.0 to 14.5 GHz. There are more than 22 FSS Ku band satellites orbiting over North America, each carrying 12 to 48 transponders
Transponder (Satellite communications)
A communications satellite’s transponder, is the series of interconnected units which form a communications channel between the receiving and the transmitting antennas .A transponder is typically composed of:...
, 20 to 120 watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
s per transponder, and requiring a 0.8-m to 1.5-m antenna for clear reception.
The 12.2 to 12.7 GHz (LOF 11.250 GHz) segment is allocated to the BSS (broadcasting satellite service). BSS (DBS direct broadcast satellite
Direct broadcast satellite
Direct broadcast satellite is a term used to refer to satellite television broadcasts intended for home reception.A designation broader than DBS would be direct-to-home signals, or DTH. This has initially distinguished the transmissions directly intended for home viewers from cable television...
s) 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).
Europe and Africa
Segments in those regions are represented by ITU Region 1 and they are, the 11.45 to 11.7 and 12.5 to 12.75 GHz bands are allocated to the FSS (fixed satellite service, uplinkUplink
A telecommunications link is generally one of several types of information transmission paths such as those provided by communication satellites to connect two points on earth.-Uplink:...
14.0 to 14.5 GHz). In Europe Ku band is used from 10.7 to 12.75 GHz (LOF Low 9.750 GHz, LOF High 10.600 GHz) for direct broadcast satellite
Direct broadcast satellite
Direct broadcast satellite is a term used to refer to satellite television broadcasts intended for home reception.A designation broader than DBS would be direct-to-home signals, or DTH. This has initially distinguished the transmissions directly intended for home viewers from cable television...
services such as those carried by the Astra
SES Astra
Astra is the name for the geostationary communication satellites, both individually and as a group, which are owned and operated by SES S.A., a global satellite operator based in Betzdorf, in eastern Luxembourg. The name is sometimes also used to describe the channels broadcasting from these...
satellites. The 11.7 to 12.5 GHz segment is allocated to the BSS (broadcasting satellite service).
Australia
Australia is part of ITU Region 3 and the Australian regulatory environment provides a class license that covers downlinking from 12.25 GHz to 12.75 GHz and uplinking from 14.0 GHz to 14.5 GHz.Indonesia
The ITUInternational Telecommunication Union
The International Telecommunication Union is the specialized agency of the United Nations which is responsible for information and communication technologies...
has categorized Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
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
Link budget
A link budget is the accounting of all of the gains and losses from the transmitter, through the medium to the receiver in a telecommunication system. It accounts for the attenuation of...
when designing the wireless communication link. Higher power can overcome the loss to rain fade
Rain fade
Rain fade refers primarily to the absorption of a microwave radio frequency signal by atmospheric rain, snow or ice, and losses are especially prevalent at frequencies above 11 GHz. It also refers to the degradation of a signal caused by the electromagnetic interference of the leading edge of a...
.
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 transponder
Transponder
In telecommunication, the term transponder has the following meanings:...
s, and even Ka band
Ka band
The Ka band covers the frequencies of 26.5–40 GHz. 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...
transponders. Newskies (NSS 6), launched in December 2002 and positioned at 95° East, contains only Ku-band transponders with a footprint on Indonesia (Sumatra
Sumatra
Sumatra is an island in western Indonesia, westernmost of the Sunda Islands. It is the largest island entirely in Indonesia , and the sixth largest island in the world at 473,481 km2 with a population of 50,365,538...
, Java
Java
Java is an island of Indonesia. With a population of 135 million , it is the world's most populous island, and one of the most densely populated regions in the world. It is home to 60% of Indonesia's population. The Indonesian capital city, Jakarta, is in west Java...
, Borneo
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
, Celebes
Sulawesi
Sulawesi is one of the four larger Sunda Islands of Indonesia and is situated between Borneo and the Maluku Islands. In Indonesia, only Sumatra, Borneo, and Papua are larger in territory, and only Java and Sumatra have larger Indonesian populations.- Etymology :The Portuguese were the first to...
, Bali
Bali
Bali is an Indonesian island located in the westernmost end of the Lesser Sunda Islands, lying between Java to the west and Lombok to the east...
, Nusa Tenggara, Moluccas). The iPSTAR satellite, launched in 2004 also uses Ku band footprints. MEASAT
MEASAT
MEASAT Satellite Systems Sdn. Bhd., formerly Binariang Satellite Systems Sdn. Bhd is a Malaysian communications satellite operator.MEASAT is the name of a line of communications satellites owned and operated by the company.As of 2006, the MEASAT satellite network consists of three geostationary...
has named the Ku-band footprint directed towards Indonesia Ku-band for Indonesi. MEASAT-3
MEASAT-3
MEASAT-3 was successfully launched on December 12, 2006, 7.35 am from the Baikonur Cosmodrome, Kazakhstan.In March 2003, MEASAT Satellite Systems Sdn. Bhd. of Malaysia ordered a Boeing 601HP satellite, giving it the designation MEASAT-3 at that time...
plans to cover the whole of Indonesia from West to East. This satellite was launched by Malaysia in December 2006.
Others
Other ITU allocations have been made within the Ku band to the fixed service (microwave towers), radio astronomy service, space research service, mobile service, mobile satellite service, radiolocation service (radar), amateur radio serviceAmateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...
, and radionavigation. However, not all of these services are actually operating in this band and others are only minor users.
Advantages
Compared with C-band, Ku band is not similarly restricted in power to avoid interference with terrestrial microwave systems, and the power of its uplinks and downlinks can be increased. This higher power also translates into smaller receiving dishes and points out a generalization between a satellite's transmission and a dish's size. As the power increases, the dish's size can decrease. This is because the purpose of the dish element of the antenna is to collect the incident waves over an area and focus them all onto the antenna's actual receiving element, mounted in front of the dish (and pointed back towards its face); if the waves are more intense, fewer of them need to be collected to achieve the same intensity at the receiving element.The Ku band also offers a user more flexibility. A smaller dish size and a Ku band system's freedom from terrestrial operations simplifies finding a suitable dish site. For the end users Ku band is generally cheaper and enables smaller antennas (both because of the higher frequency and a more focused beam). Ku band is also less vulnerable to rain fade than the Ka band frequency spectrum.
The satellite operator's Earth Station antenna do require more accurate position control when operating at Ku band than compared to C band. Position feedback accuracies are higher and the antenna may require a closed loop control system to maintain position under wind loading of the dish surface.
Disadvantages
There are, however, some disadvantages of Ku band system. Especially at frequencies higher than 10 GHz in heavy rain fall areas, a noticeable degradation occurs, due to the problems caused by and proportional to the amount of rainfall (commonly known as "rain fadeRain fade
Rain fade refers primarily to the absorption of a microwave radio frequency signal by atmospheric rain, snow or ice, and losses are especially prevalent at frequencies above 11 GHz. It also refers to the degradation of a signal caused by the electromagnetic interference of the leading edge of a...
"). This problem can be mitigated, however, by deploying an appropriate link budget strategy when designing the satellite network, and allocating a higher power consumption to compensate rain fade loss. The Ku band is not only used for television transmission, which some sources imply, but also very much for digital data transmission via satellites, and for voice/audio transmissions.
The higher frequency spectrum of the Ku band is particularly susceptible to signal degradation, considerably more so than C-band satellite frequency spectrum. A similar phenomenon, called "snow fade" (where snow or ice accumulation significantly alters the focal point of a dish) can also occur during winter precipitation. Also, the Ku band satellites typically require considerably more power to transmit than the C-band satellites. Under both "rain fade
Rain fade
Rain fade refers primarily to the absorption of a microwave radio frequency signal by atmospheric rain, snow or ice, and losses are especially prevalent at frequencies above 11 GHz. It also refers to the degradation of a signal caused by the electromagnetic interference of the leading edge of a...
" and "snow fade" conditions, Ka and Ku band losses can be marginally reduced using super-hydrophobic Lotus effect
Lotus effect
The lotus effect refers to the very high water repellence exhibited by the leaves of the lotus flower ....
coatings.
Other Microwave Bands
The microwave spectrum is usually defined as electromagnetic energy ranging from approximately 1 GHz to 100 GHz in frequency, but older usage includes lower frequencies. Most common applications are within the 1 to 40 GHz range. Microwave frequency bands, as defined by the Radio Society of Great BritainRadio Society of Great Britain
First founded in 1913 as the London Wireless Club, the Radio Society of Great Britain is the United Kingdom's recognised national society for amateur radio operators. The society's patron is Prince Philip, Duke of Edinburgh and it represents the interests of the UK’s 60,000 licensed radio amateurs...
(RSGB), are shown in the table below:
| L band L band L band refers to four different bands of the electromagnetic spectrum: 40 to 60 GHz , 1 to 2 GHz , 1565 nm to 1625 nm , and around 3.5 micrometres .-NATO L band:... |
1 to 2 GHz |
| S band S band The S band is defined by an IEEE standard for radio waves with frequencies that range from 2 to 4 GHz, crossing the conventional boundary between UHF and SHF at 3.0 GHz. It is part of the microwave band of the electromagnetic spectrum... |
2 to 4 GHz |
| C band C band The C band is a name given to certain portions of the electromagnetic spectrum, including wavelengths of microwaves that are used for long-distance radio telecommunications. The IEEE C-band - and its slight variations - contains frequency ranges that are used for many satellite communications... |
4 to 8 GHz |
| X band X band The X band is a segment of the microwave radio region of the electromagnetic spectrum. In some cases, such as in communication engineering, the frequency range of X band is rather indefinitely set at approximately 7.0 to 11.2 gigahertz . In radar engineering, the frequency range is specified... |
8 to 12 GHz |
| Ku band | 12-18 GHz |
| K band K band K band designates certain portions of the electromagnetic spectrum, in either the microwave domain or in the infrared domain. The microwave K bands are used primarily for radar and satellite communications while the infrared K band is used for astronomical observations.-NATO K band:The NATO K band... |
18 to 26.5 GHz |
| Ka band Ka band The Ka band covers the frequencies of 26.5–40 GHz. 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... |
26.5 to 40 GHz |
| Q band Q band The Q band of the microwave part of the electromagnetic spectrum and ranges from 33 to 50 GHz. It sits above, and partly overlaps with, the U.S. IEEE designated Ka band . It sits below the U.S... |
30 to 50 GHz |
| U band | 40 to 60 GHz |
| V band V band The V band of the electromagnetic spectrum ranges from 50 to 75 GHz. The V band is not heavily used, except for millimeter wave radar research and other kinds of scientific research... |
50 to 75 GHz |
| D band D band IEEE D band is the range of radio frequencies from 110 GHz to 170 GHz in the electromagnetic spectrum. This is equal to wave lengths between 1.8 mm and 2.7 mm... |
110 to 170 GHz |
Footnote: P band is sometimes incorrectly used for Ku Band. "P" for "previous" was a radar band used in the UK ranging from 250 to 500 MHz and now obsolete per IEEE Std 521, see http://www.radioing.com/eengineer/bands.html and http://www.microwaves101.com/encyclopedia/letterbands.cfm. For other definitions see Letter Designations of Microwave Bands