Satellite dish

Type of parabolic antenna

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Antennas

Common types

* Dipole
* Fractal
* Loop
* Monopole
* Satellite dish
* Television
* Whip

Components

* Balun
* Block upconverter
* Coaxial cable
* Counterpoise (ground system)
* Feed
* Feed line
* Low-noise block downconverter
* Passive radiator
* Receiver
* Rotator
* Stub
* Transmitter
* Tuner
* Twin-lead

Systems

* Antenna farm
* Amateur radio
* Cellular network
* Hotspot
* Municipal wireless network
* Radio
* Radio masts and towers
* Wi-Fi
* Wireless

Safety and regulation

* Wireless device radiation and health
* Wireless electronic devices and health
* International Telecommunication Union
(Radio Regulations)

* World Radiocommunication Conference

Radiation sources / regions

* Boresight
* Focal cloud
* Ground plane
* Main lobe
* Near and far field
* Side lobe
* Vertical plane

Characteristics

* Array gain
* Directivity
* Efficiency
* Electrical length
* Equivalent radius
* Factor
* Friis transmission equation
* Gain
* Height
* Radiation pattern
* Radiation resistance
* Radio propagation
* Radio spectrum
* Signal-to-noise ratio
* Spurious emission

Techniques

* Beam steering
* Beam tilt
* Beamforming
* Small cell

* Bell Laboratories Layered
Space-Time (BLAST)

* Massive Multiple-input multiple-output (MIMO)

* Reconfiguration
* Spread spectrum

* Wideband Space Division
Multiple Access (WSDMA)

* v
* t
* e

A satellite dish is a dish-shaped type of parabolic antenna designed to receive or transmit information by radio waves to or from a communication satellite. The term most commonly means a dish which receives direct-broadcast satellite television from a direct broadcast satellite in geostationary orbit.

## History

[edit]

Parabolic or "dish" antennas had been in use as radio telescopes (beginning in 1937) and airplane tracking by the military (during WWII) long before the first artificial satellite was launched in 1957.

The term satellite dish was coined in 1978 during the beginning of the satellite television industry, and came to refer to dish antennas that send and/or receive signals from communications satellites. Taylor Howard of San Andreas, California, adapted an ex-military dish in 1976 and became the first person to receive satellite television signals using it.[1]

The first satellite television dishes were built to receive signals on the C-band analog, and were very large. The front cover of the 1979 Neiman-Marcus Christmas catalog featured the first home satellite TV stations on sale.[2] The dishes were nearly 20 feet (6.1 m) in diameter.[3] The satellite dishes of the early 1980s were 10 to 16 feet (3.0 to 4.9 m) in diameter[4] and made of fiberglass with an embedded layer of wire mesh or aluminium foil, or solid aluminium or steel.[5]

Satellite dishes made of wire mesh first came out in the early 1980s, and were at first 10 feet (3.0 m) in diameter. As the front-end technology improved and the noise figure of the LNBs fell, the size shrank to 8 feet (2.4 m) a few years later, and continued to get smaller reducing to 6 feet (1.8 m) feet by the late 1980s and 4 feet (1.2 m) by the early 1990s.[6] Larger dishes continued to be used, however.[6] In December 1988, Luxembourg's Astra 1A satellite began transmitting analog television signals on the Ku band for the European market.[7] This allowed small dishes (90 cm) to be used reliably for the first time.[7]

In the early 1990s, four large American cable companies founded PrimeStar, a direct broadcasting company using medium power satellites.[8] The relatively strong Ku band transmissions allowed the use of dishes as small as 90 cm for the first time.[8] On 4 March 1996, EchoStar introduced Digital Sky Highway (Dish Network).[9] This was the first widely used direct-broadcast satellite television system and allowed dishes as small as 20 inches (51 cm) to be used. This great decrease of dish size also allowed satellite dishes to be installed on vehicles.[10] Dishes this size are still in use today. Television stations, however, still prefer to transmit their signals on the C-band analog with large dishes due to the fact that C-band signals are less prone to rain fade than Ku band signals.[11]

## Principle of operation

[edit]

Schematics of reflection principles used in parabolic antennas

The parabolic shape of a dish reflects the signal to the dish's focal point. Mounted on brackets at the dish's focal point is a device called a feedhorn. This feedhorn is essentially the front-end of a waveguide that gathers the signals at or near the focal point and 'conducts' them to a low-noise block downconverter or LNB. The LNB converts the signals from electromagnetic or radio waves to electrical signals and shifts the signals from the downlinked C-band and/or Ku-band to the L-band range. Direct broadcast satellite dishes use an LNBF, which integrates the feedhorn with the LNB. A new form of omnidirectional satellite antenna, which does not use a directed parabolic dish and can be used on a mobile platform such as a vehicle was announced by the University of Waterloo in 2004.[12]

The theoretical gain (directive gain) of a dish increases as the frequency increases. The actual gain depends on many factors including surface finish, accuracy of shape, feedhorn matching. A typical value for a consumer type 60 cm satellite dish at 11.75 GHz is 37.50 dB.

With lower frequencies, C-band for example, dish designers have a wider choice of materials. The large size of dish required for lower frequencies led to the dishes being constructed from metal mesh on a metal framework. At higher frequencies, mesh type designs are rarer though some designs have used a solid dish with perforations.

A common misconception is that the LNBF (low-noise block/feedhorn), the device at the front of the dish, receives the signal directly from the atmosphere. For instance, one BBC News downlink shows a "red signal" being received by the LNBF directly instead of being beamed to the dish, which because of its parabolic shape will collect the signal into a smaller area and deliver it to the LNBF.[13]

Modern dishes intended for home television use are generally 43 cm (18 in) to 80 cm (31 in) in diameter, and are fixed in one position, for Ku-band reception from one orbital position. Prior to the existence of direct broadcast satellite services, home users would generally have a motorised C-band dish of up to 3 m in diameter for reception of channels from different satellites. Overly small dishes can still cause problems, however, including rain fade and interference from adjacent satellites.

## Europe

[edit]

In Europe, the frequencies used by DBS services are 10.7–12.75 GHz on two polarisations H (Horizontal) and V (Vertical). This range is divided into a "low band" with 10.7–11.7 GHz, and a "high band" with 11.7–12.75 GHz. This results in two frequency bands, each with a bandwidth of about 1 GHz, each with two possible polarizations. In the LNB they become down converted to 950–2150 MHz, which is the frequency range allocated for the satellite service on the coaxial cable between LNBF and receiver. Lower frequencies are allocated to cable and terrestrial TV, FM radio, etc. Only one of these frequency bands fits on the coaxial cable, so each of these bands needs a separate cable from the LNBF to a switching matrix or the receiver needs to select one of the 4 possibilities at a time.[citation needed]

## Systems design

[edit]

In a single receiver residential installation there is a single coaxial cable running from the receiver set-top box in the building to the LNB on the dish. The DC electric power for the LNB is provided through the same coaxial cable conductors that carry the signal to the receiver. In addition, control signals are also transmitted from the receiver to the LNB through the cable. The receiver uses different power supply voltages (13 / 18 V) to select vertical / horizontal antenna polarization, and an on/off pilot tone (22 kHz) to instruct the LNB to select one of the two frequency bands. In larger installations each band and polarization is given its own cable, so there are 4 cables from the LNB to a 'multiswitch' switching matrix, which allows the connection of multiple receivers to the multiswitch in a star topology using the same signalling method as in a single receiver installation.[citation needed]

### Satellite finder

[edit]

Sat finder

A satellite finder (or sat finder) is a satellite field strength meter used to accurately point satellite dishes at communications satellites in geostationary orbit.[14] Professional satellite finder meters allow better dish alignment and provide received signal parameter values as well.

## Types

[edit]

### Motor-driven dish

[edit]

A dish that is mounted on a pole and driven by a stepper motor or a servo can be controlled and rotated to face any satellite position in the sky. There are three competing standards: DiSEqC, USALS, and 36 V positioners. Many receivers support all of these standards.

Motor-driven dishes come in a variety of sizes, but a dish of at least 120 centimetres (47 in) is required to receive signals from distant satellites which are intended to serve other areas.[citation needed]

With DiSEqC and USALS, the satellite dish will automatically aim itself at one of sixteen satellites programmed in previously when pressing one of the channel buttons on the remote.[citation needed] Motor-driven satellite dishes using USALS can detect other satellites in a constellation after one has been found and aimed at.[citation needed]

Most receivers sold at present[when?] are compatible with USALS and DiSEqC 1.0 and 1.2.

### Multi-satellite

[edit]

Special dish for up to 16 satellite positions (Ku-band)

Every standard-size dish enables simultaneous reception from multiple different satellite positions without re-positioning the dish, just by adding additional LNB or using special duo LNB, or triple- or four-feed monoblock LNB.

However, some designs much more effectively optimize simultaneous reception from multiple different satellite positions without re-positioning the dish. The vertical axis operates as an off-axis concave parabolic concave hyperbolic[clarification needed] Cassegrain reflector, while the horizontal axis operates as a concave convex[clarification needed] Cassegrain. The spot from the main dish wanders across the secondary, which corrects astigmatism by its varying curvature. The elliptic aperture of the primary is designed to fit the deformed illumination by the horns. Due to double spill-over, this makes more sense for a large dish.

Switching between satellites is possible by using DiSEqC switches added to a satellite installation, or built-in Duo LNBs or Monoblock LNBs.

Most receivers sold presently[when?] are compatible with at least DiSEqC 1.0, which can switch automatically between 4 satellites (all of contemporary Monoblock LNBs) as the user changes channels using the remote control.

DiSEqC 1.1 allows for switching automatically between 16 satellite positions or more (through cascading switches).

Motor-driven dishes assure better optimal focusing for the given dish size; LNB is always in central alignment with the broadcasting satellite, but DiSEqC switches are faster than DiSEqC motors as no physical movement is required.[citation needed]

### VSAT

[edit]

A common type of dish is the very small aperture terminal (VSAT). This provides two way satellite Internet communications for both individuals and private networks for organizations. At present,[when?] most VSATs operate in Ku band; C band is restricted to less populated regions of the world. In 2005, dish manufacturers began moving towards new Ka band satellites operating at higher frequencies, offering greater performance at lower cost.[citation needed] These antennas vary from 74 to 120 cm (29 to 47 in) in most applications though C-band VSATs may be as large as 4 m (13 ft).

### Homemade dishes

[edit]

Any metal surface which concentrates a significant fraction of the reflected microwaves at a focus can be used as a dish antenna, at a lower gain. This has led to trash can lids, woks, and other items being used as "dishes". Only modern low noise LNBs and the higher transmission power of DTH satellites allows a usable signal to be received from such inefficient DIY antennas.

### Others

[edit]

* Individual dishes serving one dwelling: Direct to Home (DTH).
* Collective dishes, shared by several dwellings: satellite master antenna television (SMATV) or communal antenna broadcast distribution (CABD).
* Automatic Tracking Satellite Dish

## Gallery

[edit]

* General Electric satellite dish for DirecTV satellite television.

* Sky "minidish".

* Satellite dishes installed on an apartment complex.

* The back side of an old C-band satellite dish showing the pole, mount, motor, and structure of the dish.

* Satellite dishes above CCTV Headquarters.

* A WWE HD satellite truck in a parking lot.

* Satellite dish at a hut in East Timor

## See also

[edit]

* Free-to-air
* USALS = Universal Satellites Automatic Location System
* DiSEqC = Digital Satellite Equipment Control
* SAT>IP end user consumer equipment that can switch different ip streams from different SAT>IP servers and facilitates selection of reception from different satellites
* Satellite television
* Set-top box
* Parabolic reflector
* Low-noise block converter
* Automatic Tracking Satellite Dish
* Starlink Dish

## References

[edit]

1. ^ Feder, Barnaby J. (15 November 2002). "Taylor Howard, 70, Pioneer In Satellite TV for the Home". New York Times. Retrieved 19 July 2014.
2. ^ Browne, Ray (2001). The Guide to United States Popular Culture. Madison, Wisconsin: Popular Press. p. 706\. ISBN 9780879728212. Retrieved 1 July 2014.
3. ^ Giarrusso, Michael (28 July 1996). "Tiny Satellite Dishes Sprout in Rural Areas". Los Angeles Times. Los Angeles. Retrieved 1 July 2014.
4. ^ Nye, Doug (14 January 1990). "SATELLITE DISHES SURVIVE GREAT SCRAMBLE OF 1980S". Deseret News. Salt Lake City: Deseret News. Archived from the original on August 8, 2014. Retrieved 30 June 2014.
5. ^ Brooks, Andree (10 October 1993). "Old satellite dish restrictions under fire New laws urged for smaller models". The Baltimore Sun. Baltimore, MD: The Baltimore Sun. Retrieved 1 July 2014.
6. ^ a b Somerfield, Harry (30 September 1990). "Satellite dishes getting smaller, sharper in future". The Tuscaloosa News. Tuscaloosa, Alabama. Retrieved 7 August 2014.
7. ^ a b "ASTRA 1A Satellite details 1988-109B NORAD 19688". N2YO. 9 July 2014. Retrieved 12 July 2014.
8. ^ a b Barber, Dave (18 August 1995). "500,000 families already made PRIMESTAR their choice in satellite TV". Bangor Daily News. Bangor, Maine. Retrieved 7 August 2014.
9. ^ Grant, August E. (2010). Communication Technology Update (10th ed.). Taylor & Francis. p. 87\. ISBN 978-0-240-81475-9.
10. ^ Evangelista, Benny (10 November 2003). "Satellite TV in the car, on the move / New technology makes dish receivers small enough to fit atop an SUV". San Francisco Chronicle. San Francisco. Retrieved 7 August 2014.
11. ^ "Rain fade: satellite TV signal and adverse weather". Dish-cable.com. 2010. Retrieved 16 July 2014.
12. ^ "Team develops in-car satellite TV". University of Waterloo. 2006-05-06. Archived from the original on May 14, 2006. Retrieved 2008-04-29.
13. ^ "News 24 STILL gets an F for physics". Retrieved 2008-04-29.
14. ^ "SATELLITE FINDER METER - Winegard" (PDF).

## External links

[edit]

Wikimedia Commons has media related to Satellite dishes (residential).

* European Commission: The right to use a satellite dish.
* DishPointer – Satellite dish alignment with Google Maps.
* Guide explaining how to self install freesat
* Online Satellite Finder Based on Google Maps

* v
* t
* e

Satellite communications

Main articles|

* Satellite television
* Satellite radio
* Satellite Internet access
* Amateur satellite
* Ground station
* High-throughput satellite
* Relay satellite
* Transponder
* Carriage dispute

Hardware|

* SAT>IP
* Monoblock LNB
* DiSEqC
* USALS
* Automatic Tracking Satellite Dish
* Motor-driven Satellite dish
* Multi-satellite
* Satellite dish (Parabolic antennas)
* Satellite phone
* Satellite modem
* Satellite data unit
* Spacebus
* Very-small-aperture terminal

Satellite radio / TV|

* DVB-SH
* S-DMB
* DVB-RCS
* DVB-S2
* DVB-S2X
* ISDB-S3
* Digital audio radio service

Broadcast companies|

* Astra Digital Radio
* DirecTV
* Dish Network
* Sirius XM Holdings
* Sky UK
* Allente
* 1worldspace

Relay satellite companies|

* AST SpaceMobile
* EchoStar
* Eutelsat
* Globalstar
* Hispasat
* Hughes
* Inmarsat
* Intelsat
* Intersputnik
* Iridium
* SED Systems
* SES
* Shanghai Spacecom Satellite Technology
* Star One
* Starlink
* Telesat
* Tooway
* Turksat
* Viasat

Satellite manufacturers|

* Airbus
* Boeing
* INVAP
* Lockheed Martin
* Northrop Grumman
* SpaceX
* SSL
* Thales Alenia Space

Trade organizations|

* Consultative Committee for Space Data Systems
* ETSI Satellite Digital Radio

Lists|

* List of communications satellite firsts
* List of communication satellite companies

* Category

* v
* t
* e

Telecommunications

History|

* Beacon
* Broadcasting
* Cable protection system
* Cable TV
* Communications satellite
* Computer network
* Data compression
* audio
* DCT
* image
* video
* Digital media
* Internet video
* online video platform
* social media
* streaming
* Drums
* Edholm's law
* Electrical telegraph
* Fax
* Heliographs
* Hydraulic telegraph
* Information Age
* Information revolution
* Internet
* Mass media
* Mobile phone
* Smartphone
* Optical telecommunication
* Optical telegraphy
* Pager
* Photophone
* Prepaid mobile phone
* Radio
* Radiotelephone
* Satellite communications
* Semaphore
* Phryctoria
* Semiconductor
* device
* MOSFET
* transistor
* Smoke signals
* Telecommunications history
* Telautograph
* Telegraphy
* Teleprinter (teletype)
* Telephone
* The Telephone Cases
* Television
* digital
* streaming
* Undersea telegraph line
* Videotelephony
* Whistled language
* Wireless revolution

Pioneers|

* Nasir Ahmed
* Edwin Howard Armstrong
* Mohamed M. Atalla
* John Logie Baird
* Paul Baran
* John Bardeen
* Alexander Graham Bell
* Emile Berliner
* Tim Berners-Lee
* Francis Blake
* Jagadish Chandra Bose
* Charles Bourseul
* Walter Houser Brattain
* Vint Cerf
* Claude Chappe
* Yogen Dalal
* Donald Davies
* Daniel Davis Jr.
* Amos Dolbear
* Thomas Edison
* Philo Farnsworth
* Reginald Fessenden
* Lee de Forest
* Elisha Gray
* Oliver Heaviside
* Robert Hooke
* Erna Schneider Hoover
* Harold Hopkins
* Gardiner Greene Hubbard
* Bob Kahn
* Dawon Kahng
* Charles K. Kao
* Narinder Singh Kapany
* Hedy Lamarr
* Roberto Landell
* Innocenzo Manzetti
* Guglielmo Marconi
* Robert Metcalfe
* Antonio Meucci
* Samuel Morse
* Jun-ichi Nishizawa
* Charles Grafton Page
* Radia Perlman
* Alexander Stepanovich Popov
* Tivadar Puskás
* Johann Philipp Reis
* Claude Shannon
* Almon Brown Strowger
* Henry Sutton
* Charles Sumner Tainter
* Nikola Tesla
* Camille Tissot
* Alfred Vail
* Thomas A. Watson
* Charles Wheatstone
* Vladimir K. Zworykin
* Internet pioneers

Transmission
media|

* Coaxial cable
* Fiber-optic communication
* optical fiber
* Free-space optical communication
* Molecular communication
* Radio waves
* wireless
* Transmission line
* telecommunication circuit

Network topology
and switching|

* Bandwidth
* Links
* Network switching
* circuit
* packet
* Nodes
* terminal
* Telephone exchange

Multiplexing|

* Space-division
* Frequency-division
* Time-division
* Polarization-division
* Orbital angular-momentum
* Code-division

Concepts|

* Communication protocol
* Computer network
* Data transmission
* Store and forward
* Telecommunications equipment

Types of network|

* Cellular network
* Ethernet
* ISDN
* LAN
* Mobile
* NGN
* Public Switched Telephone
* Radio
* Television
* Telex
* UUCP
* WAN
* Wireless network

Notable networks|

* ARPANET
* BITNET
* CYCLADES
* FidoNet
* Internet
* Internet2
* JANET
* NPL network
* TANet
* Toasternet
* Usenet

Locations|

* Africa
* Americas
* North
* South
* Antarctica
* Asia
* Europe
* Oceania
* Global telecommunications regulation bodies

* Telecommunication portal
* Category
* Outline
* Commons

Authority control databases

National|

* Germany
* United States
* Israel

Other|

* Yale LUX

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