Dish network comprises of directional antenna that is utilized mainly for capturing radio and microwaves using parabolic reflectors. The working principle is that all plane parallel waves which are incoming are received by the parabola and are converted into spherical wave that converges at a point. The first parabolic antenna used for television communication was found in 1862 and communicated with the Telstar satellite. Antenna is a transducer and can receive electromagnetic waves and it transmits electromagnetic waves, especially radio waves. The dish network is a highly directive one which can direct radio waves into a narrow beam and also receive waves from a specific direction only. It can receive from very distant sources. After the television read-only (TVRO) and data broadcasting satellite dishes came into existence, these dish antennas have become a common feature not only in urban but also rural areas. High-gain dish antennas are preferred. The world’s largest dish antenna is the Arecibo Observatory’s radio telescope which has a gain of 10 million and diameter of 1000ft . There are various criteria that define the efficiency of dish network , which include its bandwidth, impedance, resonance frequency, efficiency, radiation pattern, gain and polarization. Dish antennas are mainly used in broadcasting systems like the radio, television, wireless Local Area Network and cell phones. Other interesting application of dish antenna is also seen in its usage in the spacecraft communication and radars. Antenna can be installed not only in air, outer space but also in the submarine. It is interesting to note that it can also work underground.
