In order to receive a satellite broadcast signal from broadcasting satellite or communications satellite, it is necessary to install a satellite receiver and a satellite dish antenna. A parabolic dish antenna comprises, essentially, a parabolic reflector dish, an antenna feed at the focal point of the reflector, a support which typically encloses some sort of signal conductor such as coaxial cable, and the electronics of the dish which are normally enclosed within some sort of protective cover. A typical satellite receive antenna uses a parabolic reflector dish to reflect and concentrate signals to a focal point. Radio waves from a distant radio source or a radio transmitter, are reflected by the paraboloidal reflector surface and are concentrated at the focal point of the dish antenna, where they are received by a primary antenna feed and an amplifier unit. The reflector collects and focuses the satellite signal onto the LNBF which is connected, via cable, to the subscriber's television. The dish-shaped reflector has a support arm protruding outward from the front surface of the reflector. The support arm supports a low noise block amplifier with an integrated feed LNBF. A feed horn or waveguide is positioned at the focal point to receive the focused signals. The feed horn directs the concentrated signals to a probe which responds to the focused signals by producing a small electrical signal. The parabolic antenna receives a signal from a satellite, and a satellite receiver takes images and sounds from the received signal and then transfers them to an output device such as a television and a speaker. Typically, a multibeam satellite communications system geographically divides the earth's surface into a number of circular or hexagonal geographic areas called cells. Each cell is serviced by different communication channels on the satellite. The communication channel between the satellite and the cell is typically referred to as a spot beam. A satellite communications system may produce several spot beams from a single satellite-mounted antenna. For example, the satellite-mounted antenna may be parabolic or spherical and multiple feeds may supply signals to a single antenna. The signals supplied by the multiple feeds may be directed to the desired cells using the geometry of the antenna.

The parabolic reflector antenna is a high gain antenna with orientation that is mostly used in radar systems, microwave systems and satellite systems. The parabolic reflector antenna comprises two main components: one is a parabolic reflector and the other is a feedback active unit. The reflector is shaped into one that can readily collect radio signals. It is also termed open antenna. The reflector is a passive device with no power. It is solely used to focus and direct the electromagnetic energy supplied from the original antenna by reflecting and to spread the energy into space. The reflector gathers radio or microwave frequency energy transmitted from the feed horn or through the ambient environment from an external transmitter. Usually, the electromagnetic energy is directed toward the reflector using dipoles, dipole arrays, and waveguides. Since the dimension of the reflector is much larger than the signal wavelength, so it can be applied to electromagnetic radiation. The reflector surface of the parabolic dish antennas consists of a number of plane or curved panels, made out of metal or metallized sheets or wire mesh, which are supported by a back-up-structure. The reflecting surface, the back-up-structure and a supporting structure for the antenna feed form the main elements of the parabolic dish antenna. Parabolic reflector antennas developed and currently produced for satellite ground applications use are made by forming aluminum sheet on a mandrel by a spinning process. Satellite dish antennas may be forty feet or more in diameter and are fabricated using preformed metal panels or are plastic molded on parabolic forms. The plastic reflectors are metalized to make the surface reflective. Dish antennas have also been formed from a plurality of wedged-shaped antenna sections of metal mesh which are capable of reflecting the transmitted radio waves and which are supported in the dish shape by rigid radial ribs. Dish antennas formed of sections of metal mesh allows air to pass through, resulting in a lower wind load than would exist in a solid antenna of the same size. The major advantage of mesh antennas over solid metal dishes is that the mesh antenna can be shipped in pieces in compact packages whereas the solid dishes are extremely large and bulky, requiring special handling procedures, and consequently are expensive to ship.

In a typical dish antenna, the frame which supports the reflector dish is usually a complex structure. It may be an inverted geodesic dome, or a series of concentric hoops supported by a plurality of identical sub-frames extending radically from below the centre of the dish. Some of the antenna dish systems used for satellite communication systems have linear actuators that drive the antenna dish to track a satellite. Typically, a linear actuator has a line of action from its output shaft that is located a distance from the antenna axis rotation to provide a moment arm. Satellite dishes are exposed to the environment and as such are subject to exposure to water, snow, wind, sun and other environmental related stresses. These stresses are detrimental. For example, the weight of accumulated snow and/or ice may distort the shape of the parabolic reflecting surface. Such physical distortion, by affecting the integrity of the parabolic shape of the reflecting surface, may significantly degrade the performance of the antenna. Therefore, it is necessary to protect the electronic components and coaxial cables from the exposure to snow and water and also to physically stabilize the receiving/transmitting horn against the wind to maintain the physical position of the horn within the satellite dish. Thus, a variety of forms of covers have been developed for parabolic antennas, mostly for protection against any adverse weather conditions. Such covers have typically been made of rigid plastic material with a spherical or parabolic shape completely enclosing the face of the parabolic antenna including the feed structure located near the focus of the parabola. Typical insulating covers passively retain heat generated by the heating element by insulating the heated portion or surface of the dish antenna from the ambient environment. Such a passive insulating cover may be constructed of a dense and relatively heavy, material, in order to achieve a certain insulation factor and/or efficiency. The satellite dish covers tend to be rather loosely fitting covers which were either flat or extended over some part of the receiver horn support structure. Typical insulating covers and/or heating element devices for dish antennas are installed adjacent to the rear side of the parabolic reflector and are physically attached to the outer rim of the dish antenna.

Satellite dishes require careful alignment in order to achieve a good reception performance because a parabolic dish antenna has very strong directivity. The transmission of communications signals from the satellite is along a direct line-of-sight path, an antenna used to receive such signals from geosynchronous satellites must be pointed accurately toward the satellite in its orbital position. When the direction of the parabolic dish antenna is displaced, the output to the satellite receiver is reduced. The reduction of output to the satellite receiver causes a harmful effect such as distortion of images and sounds, and may cause the receiver failure. To obtain a good signal, the satellite dish must be pointed precisely (within 2 degrees in all directions) and directly at the satellite, with no obstructions between the two. To align an antenna with a particular satellite, the installer must be provided with accurate positioning information for that particular satellite. In each antenna's installation, there are three adjustments which must be made to properly orient the antenna to track the arc of satellites. These include elevation, declination, and azimuth. Elevation is the angle that the axis of rotation forms with respect to horizontal. Declination represents the angle that the center axis of the dish forms with respect to the axis of rotation. The azimuth setting is the compass direction that the antenna should be pointed relative to magnetic north. Azimuth represents the horizon-to-horizon movement of the antenna as necessary to move from one satellite to another. The satellite dish must have an extremely stable base to provide constant support so the dish can be aligned to receive the signals from a satellite. To obtain a stable base for the satellite dish, it is preferred to secure the satellite dish mounting base directly to the roof structure and into the underlying support structure.

The performance of a typical dish antenna is dependent upon and greatly affected by the geometrical accuracy of the shape of the parabolic reflective surface and the position of the amplifying unit relative to the focal point of the reflected electromagnetic signals. If the parabolic reflective surface of the dish antenna is deformed, the electromagnetic signals may not be reflected to a single focal point. Antenna dish systems vary in their size and can range from having a large antenna dish that is many meters wide to small, portable antenna dishes that are about one meter wide. One of the reasons for the size of these reflector dishes is that is an important factor in determining the quality of the reception. The cross-sectional area of the main reflector dish projected into a plane defines the aperture of the dish, and the larger the aperture, the better the reception, all other things being equal. Therefore, a larger dish size adds to performance. In recent years, the huge C-band parabolic antennas previously used in satellite television systems have given way to mini-dish receivers used in direct broadcast satellite (DBS) systems, which typically range in size from 18-36 inches in diameter. These commercial mini-dish antennas are not only more affordable to consumers, but are less obtrusive than the old C-band antennas.