Some of our antennas look downright confusing. One look at this Winegard MetroStar and you might think it was a satellite dish, with its round shape and center posts. It’s not… it’s a television antenna.
The reason satellite dishes and over-the-air antennas can look similar is that at their heart, they are both antennas. They are both designed to pull in signals from somewhere else. The only important difference is how big the waves are that they need to pull in.
A satellite dish is an antenna, but the part that actually receives the signal and sends it down the line isn’t the big, round reflector — it’s the little white plastic feed horn. The big round part gathers as much signal as possible and focuses it on a single point. This works because satellite TV waves are fairly small and so a very small receiving element works fairly well with them. On the other hand, over-the-air antenna signals have fairly large waves, several feet long in some cases. Larger waves are best received by larger antennas, so the “dish” model doesn’t work with them as well. However, in some cases, small antenna elements are combined with powerful amplifiers to get the best possible result.
That’s what’s going on in the antenna at top. The round part actually is the receiving element, but it’s round because it’s designed to pull in signal from all directions at the same time. It’s small, even though a much larger antenna would do a better job, because its powerful amplifiers and clean design give it the ability to pull in signal fairly efficiently.
By the way, Wi-Fi repeaters are also antennas, and that’s why this one, which is designed to send Wi-Fi from point to point over a long distance, looks like a satellite dish. Wi-Fi’s waves are smaller than over-the-air antenna waves, but much larger than satellite TV waves. So, you get sort of a hybrid look, wit the reflector of a satellite dish but the much larger receiving element you would associate with a TV antenna.