Why are parabolic antennas used for satellite communication?

The main advantage of a parabolic antenna is that it has high directivity. It functions similarly to a searchlight or flashlight reflector to direct the radio waves in a narrow beam, or receive radio waves from one particular direction only. They are also used in radio telescopes.

What type of antenna is used in satellite communication?

Four main types of antennas are used on present communication satellites: wire antennas, horn antennas, reflector antennas, and array antennas. Wire antennas were used on the early operational satellites such as INTELSAT I and II with an antenna gain of about 4 dBi for receive and about 9 dBi for transmit.

How does a parabolic dish work?

A parabolic (or paraboloid or paraboloidal) reflector (or dish or mirror) is a reflective surface used to collect or project energy such as light, sound, or radio waves. The parabolic reflector transforms an incoming plane wave traveling along the axis into a spherical wave converging toward the focus.

What is the disadvantage of front feed parabolic antenna?

Drawbacks or disadvantages of Parabolic Reflector Antenna ➨Feed antenna and reflector disc block certain amount of radiation from the main parabolic reflector antenna. This is about 1 to 2%. This power is responsible to form side lobes in the radiation pattern. ➨Surface distortions can occur in very large dish.

What are the two main parts of a parabolic antenna?

There are two main elements to any parabolic reflector antenna:

• Radiating system: The radiating element within the parabolic reflector antenna can take a variety of forms. In some antennas it may be a simple dipole, in others a horn.
• Reflector: The reflector is the distinctive part of the parabolic reflector antenna.

Is antenna the same as satellite?

A satellite dish is an antenna, but the programming it delivers is different than a TV antenna. Your TV antenna is great for receiving all the free HDTV that’s broadcast by your local TV stations. Satellite TV brings you national stations and a variety of professional sports viewing packages.

What is the difference between satellite and antenna?

They use different methods to get programming on a TV. For instance, aerials pick up special radio waves emitted by television stations. The type of waves that will be received and the range is closely related to the aerial. On the other hand, satellite TV picks up radio signals from satellites located in the orbit.

Which feed is used in parabolic reflector antenna?

A variety of different feed techniques can be used with parabolic reflector antennas including: focal feed, Cassegrain, Gregorian, offset feed. It is possible to use one of a variety of different feed arrangements when using a parabolic reflector antenna.

Is parabolic antenna omnidirectional?

– Omni-directional antennas propagate in all directions. – Semi-directional antennas propagate in a constricted fashion, defined by a specific angle. – Directional antennas have a narrow “beam” that allows highly directional propagation; familiar types are the parabolic and Yagi.

How does a parabolic dish antenna work?

The parabolic dish works by either collecting or refracting energy. This process is facilitated by an antenna that is usually found in the center of the dish, otherwise known as the vertex.

What is the advantage of a parabolic reflective antenna?

The main advantage of a parabolic antenna is that it has high directivity. It functions similarly to a searchlight or flashlight reflector to direct the radio waves in a narrow beam, or receive radio waves from one particular direction only.

What is Gregorian antenna?

A Gregorian antenna system has the usual main reflector, subreflector, a first feed for illuminating the main reflector from the virtual focus via the subreflector, and a second feed for directly illuminating the main reflector from a prime focus.

What is a grid antenna?

A Grid Antenna is a variation of the parabolic/dish antenna. The problem with a dish antenna is that under heavy/moderate wind conditions it moves out of alignment or deforms. This is because it has a large solid surface which is usually perpendicular to the wind flow.