Transmission Process
Signals are sent up to the satellite from the earth's surface. The transmission station is called an uplink station. The transmission takes place via frequency modulation (FM). The advantage of FM is that there are no problems regarding the frequency and dynamic range that needs to be transmitted, plus, FM is less sensitive to interference than AM. For practical reasons, conventional TV stations broadcast in AM (called earth or terrestrial TV).
The outgoing transmission takes place at a very high frequency of 14,000 MHz (= 14 Gigahertz). To avoid any interference, the incoming signal (downlink) is transmitted at a frequency between 10 and 12 GHz. This is the so-called KU band, which covers the area from 10.7-12.75 GHz. The downlink signal is sent to earth in a focused beam, via a parabolic antenna, that looks quite similar to a receiving dish antenna. From there, it can be picked up by private antenna, shared antenna installations and cable companies.