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The footprint of a communications satellite is the ground area that its transponders offer coverage, and determines the satellite dish diameter required to receive each transponder's signal. There is usually a different map for each transponder (or group of transponders), as each may be aimed to cover different areas.
In small dishes such as home satellite dishes, where the size of the feed structure is comparable with the size of the dish, this can seriously reduce the antenna gain. To prevent this problem these types of antennas often use an offset feed, where the feed antenna is located to one side, outside the beam area. The aperture efficiency for these ...
Early satellite television systems were not very popular due to their expense and large dish size. [68] The satellite television dishes of the systems in the late 1970s and early 1980s were 10 to 16 feet (3.0 to 4.9 m) in diameter, [69] made of fibreglass or solid aluminum or steel, [70] and in the United States cost more than $5,000, sometimes ...
A 2.5 m parabolic dish antenna for bidirectional satellite Internet access. A very-small-aperture terminal (VSAT) [1] is a two-way satellite ground station with a dish antenna that is smaller than 3.8 meters. The majority of VSAT antennas range from 75 cm to 1.2 m. Bit rates, in most cases, range from 4 kbit/s to 16 Mbit/s.
A typical value for a consumer type 60 cm satellite dish at 11.75 GHz is 37.50 dB. With lower frequencies, C-band for example, dish designers have a wider choice of materials. The large size of dish required for lower frequencies led to the dishes being constructed from metal mesh on a metal framework.
A cantenna can be used as a satellite dish feed horn. The 5.5 GHz cantenna dimensions are almost perfect in that they make a good fit for the standard TV satellite dish. The resulting setup is a low-cost high-quality high-gain antenna. [6] Such setups are widely used in wireless community networks for long-distance Wi-Fi links.
Universal Satellites Automatic Location System (USALS), also known (unofficially) as DiSEqC 1.3, Go X or Go to XX is a satellite dish motor protocol that automatically creates a list of available satellite positions in a motorised satellite dish setup. It is used in conjunction with the DiSEqC 1.2 protocol.
For most antennas the boresight is the axis of symmetry of the antenna. For example, for axial-fed dish antennas, the antenna boresight is the axis of symmetry of the parabolic dish, and the antenna radiation pattern (the main lobe) is symmetrical about the boresight axis. Most antennas boresight axis is fixed by their shape and cannot be changed.