Satellite Dishes Are The Boon In Modern Technology |
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By: Keith Londrie Posted: 2006-09-17 22:33:41 |
| Televisions are the chewing gum for the eyes- Frank Lloyd Wright (1869 - 1959) and Satellites are the 1970's lava lamps.With the advancement of technologies, satellite television came in to existence. Satellite television is a revolution when compared to terrestrial and cable television, as it received signals from communication satellites in the space. In many places these satellite television supplement its conventional counterparts to get wide range of channels. For years, satellite television is not an acceptable one as it had many disadvantages of fixing a very large satellite in a place and then lining it to the appropriate satellite. It even took months to set it by trail and error method. Bad weather is always a hindrance to this method of broad casting.In the conventional method, the radio wave signals often disrupted and proper broadcasting was not possible as it was not inline with the antenna, which transmits these signals to the surrounding area. To get a perfect signal you should be very close to the broadcasting area. Whereas satellite television, receives the signal from satellite dishes, which is in the geo-synchronous orbit of the space. It orbits in elliptical inclination or in geostationary orbit of 37,000 km above the earth.Earlier in 1980's the Consumer satellite television reception was highly were expensive and the dishes used were as large as 12-foot height. It had a motorized, multiple satellites reception. In 1995, easily usable small dish network came in to existence. Now, direct broadcast satellite (DBS) is usage to enable the satellite provider to select programs and broadcasts them to subscribers as a set of packages. It is a digital broadcast, which means transmission happens in Ku frequency range (12 GHz to 14 GHz).Like other Satellite relayed communication, Satellite television uses an antenna, which is mainly located in uplink direction. These are mainly nine to twelve meters in diameter. These large structures are required for accurate and increased signals from satellites. These uplinked dishes placed in such a way that they receive to a particular frequency range from the satellite, which is in the space. Then these satellites in space, retransmits, or resend the signals back to these uplinked dishes in earth in a highly different frequency from the previous one. These kind of receiving the signals are termed as downlink. C-band and Ku -band are used for uplink service. The signal, received from the space, becomes weak. Therefore, these uplink dishes do conversions of the signals to low- noise block down converter. Then these radio waves get converted in to electrical signals from C-band and Ku -band to L-band. The L-band receives the signal through coaxial cable and converts in to desired output.However, the process may look very complicated. These are the units, which are the eye of the satellite television, which helps in uninterrupted service of information and makes a pathway for everybody to enjoy the new access to the information age. |
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