Antennas Used In Satellite Communication

2 explain briefly the offset feed used with paraboloidal reflector antenna stating its main advantages and disadvantages.

Antennas used in satellite communication.

They are widely used in communication links with the frequency of around 3 ghz. Nearly isotropic antennas can be constructed using multiple small elements and are used as reference antennas for testing other antennas and for field strength measurements and for backup antennas on satellites which work without the satellite being oriented towards a communication station. A variety of antenna types are used in satellite communications. The shape is generally a paraboloid of revolution.

The fundamental characteristics of the loop antenna are independent of its shape. These antennas can also be used as electromagnetic field probes in the microwave bands. Antennas in satellite communication types of antenna system use in satellite communication. It means that the.

Satellite borne communications antennas are located very far from their service area on the earth. They are also used in radio telescopes. So parabolic reflectors increase the gain of antennas in satellite communication system. For full earth coverage from a geostationary satellite a horn antenna is used.

An advantage of uhf traditionally used for military communications is that it easily penetrates deep foliage and other obstacles. The simplest physical environment occurs when the antennas are located in free space such as for communication between satellites or from an overhead satellite to ground as suggested in fig. Loop antennas are available in different shapes like circular elliptical rectangular etc. If a parabolic reflector antenna is used for transmitting a signal the signal from the feed comes out of a dipole or a horn antenna to focus the wave on to the parabola.

Uhf communications satellites often use downlink frequencies around 250mhz and uplink frequencies around 310 mhz. May 2013 may 2014 dec 2014. Hence these are used in telecommunications and broadcasting. The satellite antenna radiates electric and magnetic fields that have the radial dependence e jkr r of a spherical wave where r is the radial.

1 explain different types of antenna used in satellite communication. The most widely used narrow beam antennas are reflector antennas. Parabolic antennas are used as high gain antennas for point to point communications in applications such as microwave relay links that carry telephone and television signals between nearby cities wireless wan lan links for data communications satellite communications and spacecraft communication antennas.