The topic of our conversation today is a parabolic antenna. The fact is that many mistakenly call all antennas for satellite television. In fact, not all of these devices are parabolic antennas. This is just one type of equipment. Let us first give a definition to this concept. So, called satellite mirror equipment, designed to receive signals from satellites.
Now we pass directly to the species. A parabolic antenna is the most common of them. It is used to receive radio broadcasts, and is also intended for television and Internet access. There are two varieties of such devices.
The first variety is direct focus. This is a classic type of paraboloid of rotation. This parabolic antenna can operate both in the C-band and in the Ku-band. There is the possibility of the device also in combined mode. The second type is an offset antenna. This type is the most common for individual reception of satellite broadcasting. This antenna is an elliptical paraboloid. The focus of this segment is lower than the geometric center of the device.
This arrangement helps to eliminate the shadowing of the usable area by both the irradiator and the supports for it. Therefore, this parabolic antenna has a coefficient higher than the previous variety with the same mirror area. And the installation of the irradiator lower than the center of gravity of the antenna, allows you to increase its stability during exposure to wind, because it is mounted almost vertically.
Due to the location of the antenna in the bowl, the accumulation of precipitation is eliminated . As you know, they are able to quite strongly affect the signal quality. The angle of inclination of this antenna may vary, depending on the location in a particular geographical latitude. This type of antenna works in the same ranges as direct focus.
The next variety is toroidal antennas. This product belongs to a new category of satellite signal reception (without the use of cornering devices). Such an antenna differs from all previous devices in that its parabola has a better designed reflection surface. Thanks to the second reflector, it is possible to establish a larger number of signal receiving converters.
Such an antenna is made of special galvanized steel, which is coated with polyester varnish. On its holder can accommodate a maximum of 16 converters. Between them, a margin of at least 3 degrees is allowed. True, the installation requires strict observance of the angle, tilt and azimuth. The advantage of this antenna is that it is possible to install a special motor on it, which is capable of turning the device in the direction of the desired satellite.
Recently, a parabolic WiFi antenna has been relevant. As you guessed by the name, it is able to work without a wired connection. That, in principle, is all that I wanted to tell you about antennas.