| Satellite dishes are a kind of parabolic antennas | | | | Lower frequencies like C-band offer satellite dish |
| designed in such a way that they receive signals | | | | designers' flexibility with materials. Larger sized |
| through microwave from circulating | | | | dishes are now being designed using metal mesh |
| communication satellites. The communication | | | | within a metal framework. The lower the |
| satellites send out signals or broadcasts (satellite | | | | frequency, the more versatility in materials and |
| television) as well as data transmissions. | | | | the better the performance. However, as the |
| Due to their parabolic shape, the satellite dishes | | | | frequencies increase, metal meshes can't be used. |
| can reflect these signals to the center of the | | | | Size of Satellite Dishes |
| dishes. Typically the satellite dish is support on | | | | The modern satellite dishes that are used for |
| brackets at its center and the center or the focal | | | | Direct Home TV come in standard diameter sizes |
| point of the dish is called 'feedhorn.' The feedhorn | | | | between 43 cm (18 in) and 80 cm (31 in). These |
| is instrumental in gathering and conducting the | | | | dishes are unidirectional to catch the Ku-band |
| signals to a low-noise 'block down converter' also | | | | from other communication satellites in orbit. |
| known as Low Noise Block or LNB. | | | | Satellite Receivers |
| Low Noise Block or LNBs | | | | The receiver is the end component in the Satellite |
| What the LNB does is it converts the various | | | | TV system. The satellite receiver has 4 main jobs |
| signals emitted from radio or electromagnetic | | | | including descrambling an encrypted signal, |
| waves to a more readable electrical signal. It also | | | | converting digital formats like MPEG-2 or MPEG-4 |
| has the capability to shift the signals received | | | | signals into a format that a CTV can recognize |
| from various downlinked banks such as C and Ku | | | | such as analog, take out channel by channel from |
| to the L band. Most satellite dishes that are used | | | | a bigger satellite and lastly, to send billing |
| for direct broadcasting have an LNBF that | | | | information and pay-per-view information of the |
| combines the capabilities of both the LNB with | | | | customer back to the headquarters. |
| those of feedhorn. | | | | Satellite receivers have many other features too. |
| Recently a new omni-directional satellite aerial that | | | | From picking up programming schedule signals |
| doesn't require a parabolic dish is being used for | | | | from the providers and send those to the |
| moving platforms like a vehicle etc. | | | | customer's TV in form of onscreen program |
| Physics of Satellite Dishes | | | | guide to offer child-safe viewing etc. Satellite |
| As the frequency increases so does the directive | | | | dishes, LNBs, and receivers all work in tandem to |
| gain. However, the factual gain is really dependent | | | | offer the end user an excellent digital viewing |
| on many other factors that include the surface | | | | experience. |
| finish of the dish, the amount of accuracy | | | | With sound and picture with a movie theatre like |
| employed to create the shape, and the feedhorn | | | | quality, today satellite TV is an excellent |
| matching. The most commonly used commercial | | | | investment for all those who love to be couch |
| type satellite dishes having 60 cm diameter have | | | | potatoes. |
| a gain value of 37.50dB at 11.75 GHz. | | | | |