How does the Cassegrain reflector improve the performance of a parabolic reflector antenna?

How does the Cassegrain reflector improve the performance of a parabolic reflector antenna?

Working of a Cassegrain Antenna When the antenna acts as a transmitting antenna, the energy from the feed radiates through a horn antenna onto the hyperboloid concave reflector, which again reflects back on to the parabolic reflector. The signal gets reflected into the space from there.

What is the purpose of parabolic dishes?

Parabolic dishes focus the sunlight at a focal point beyond the center of the dish. Dish and receiver follow the Sun together including all other devices. Parabolic dishes provide the best optical performance because they do not bear cosine losses. Various systems that track the Sun on two axes are likely to be used.

Why a Cassegrain feed is used with a parabolic reflector?

Cassegrain feed is used with a parabolic reflector to allow the feed to be placed at a convenient point.

How does a parabolic reflector work?

The parabolic reflector transforms an incoming plane wave traveling along the axis into a spherical wave converging toward the focus. Conversely, a spherical wave generated by a point source placed in the focus is reflected into a plane wave propagating as a collimated beam along the axis.

What is the main advantage & disadvantage of Cassegrain reflector configuration?

Advantages Disadvantage: The feed radiator is more easily supported and the antenna is geometrically compact The subreflectors of a Cassegrain type antenna are fixed by bars. These bars and the secondary reflector constitute an obstruction for the rays coming from the primary reflector in the most effective direction.

Why are dish antennas shaped hemispherical?

Dish antenna is curved so that all the signals which fall on it can be reflected to one single point: its focus where the receiver is placed. So the strength of signal received is maximum.

What are the advantages and disadvantages of a parabolic reflector antenna?

This page covers advantages and disadvantages of Parabolic Reflector Antenna. It mentions Parabolic Reflector Antenna advantages or benefits and Parabolic Reflector Antenna disadvantages or drawbacks. What is Parabolic Reflector Antenna?

What are the factors that affect the parabolic reflector gain?

Factors affecting parabolic reflector antenna gain. Antenna efficiency: The efficiency of the antenna has a significant effect on the overall parabolic reflector gain. Typical figures are between 50 and 70%. The efficiency varies as a result of a number of different factors which are detailed below.

What is the spillover efficiency of a parabolic reflector?

Spillover Efficiency ks: The spillover efficiency is denoted as ks above. Any energy that spills over the edge of the reflector surface will reduce the efficiency and hence the parabolic reflector antenna gain. In the ideal case, the reflector surface needs to be equally and fully illuminated and none should spill over the edge.

What are the factors that affect the parabolic antenna gain?

There are a number of factors that affect the parabolic antenna gain. These factors include the following: Diameter of reflecting surface The larger the diameter of the reflecting surface of the antenna the higher the parabolic reflector gain will be.