satellite antenna device, the principle of the satellite dish

How does a satellite dish

(device of satellite antenna, principle of operation of satellite antenna)

Then I took a widespread Offset type antenna , about this, and another type of satellite antennas , by the way, is also quite common, I will stop a little later.

The main elements of any satellite dish are a spherical metal reflector (a mirror of a satellite dish) and a receiving device, the so-called satellite converter ( Fig. 1 ).

Electromagnetic radio waves (radio signal), following from a satellite, fall on a spherical mirror of a satellite dish ( Fig. 2 ), which, due to the similarity of the form, is colloquially called "dish".

Virtually any directional electromagnetic radio signal tends to be reflected from a metal surface, and the reflective properties of each metal are the better, the higher its electrical conductivity (for example, in aluminum they are higher than in steel). Therefore, this radio signal changes its direction according to the well-known law:

" The angle of incidence equals the angle of reflection "

Since the antenna's shape is spherical, the signal, falling on the effective area of ​​the mirror, is reflected only in one direction, forming a specific beam in a certain place. In other words, the radio signal reflected from the antenna mirror "focuses" at one point ( Fig. 3 ).

The receiving device, that is, the satellite converter itself, is installed in the focus emitted by the satellite antenna beam of radio waves. This converter consists of an irradiator (on which a focused signal falls) and an electronic unit of the converter. From this electronic unit, the signal, via a special coaxial cable, goes to the satellite receiver (receiver), and then to the television itself.