How small can an antenna be and still work?

What you see above you may be the world’s smallest functional antenna. It, and others like it, were used by a company called Aereo several years ago as it tried to launch a streaming TV service. That service was eventually ruled illegal, but the technology behind it is still interesting.

Aereo’s tiny antennas worked because, in general, they were under 200 feet from the broadcast transmitters they needed to reach. And that, dear friends, is the lesson — the closer you are, the smaller the antenna you need is.

Antenna science, despite, all the physics, is achingly simple. It comes down to three rules:

(1) You’ll pick up a station better if the antenna is an even fraction of the wavelength.

(2) The smaller that fraction is, the worse the antenna’s going to do.

(3) The further away you are, the weaker the signal is.

The first one is pretty simple. If you look at VHF channel 7, the signal has a wavelength of about six feet. (There are plenty of online calculators that will help you convert signal frequency to wavelength.) So, the perfect antenna for picking up channel 7 would be six feet long. However, an antenna that’s 3 feet or 1.5 feet or even .75 feet will work too.

That’s where the second thing comes in. An antenna that’s half the wavelength will do half as well picking up the signal. There’s more math to it than that, but for this article it’s not super important.

And that’s where the third thing comes into play. As you get further away, the signal gets weaker, so an antenna that’s only .75 feet may not get it. You would need a bigger one.

There’s a lot more to antenna science, but really those three things kind of rule over everything else. The bottom line is, if you want a really small antenna, you have to live close to the broadcast towers. Folks in midtown Manhattan can probably pick up channel 7 with a paperclip, but out in Lakewood, New Jersey they’re struggling even with a large antenna.

Of course we would all like to have an antenna the size of a soda can that gets all the channels for 70 miles. Advances in amplifier technology and using modern materials can help, but when it’s all said and done there isn’t any magic that will make that happen. Still, small antennas can surprise you because digital signals can be incredibly weak and still be received clearly.

If you are unsure about going up on the roof and putting up a large antenna, start with a small one. You could end up being very pleasantly surprised. Of course, the best selection is at