Boost your WiFi signal with a parabolic antenna made from a beer can

In the office, use a soda can; to save time answering user questions, spend $20 on a repeater instead

OK, this tip may not be that useful in an office where you have to be aware that the opinions of your co-workers may be based on outmoded mores that make it perfectly OK to trip out on caffeine during the day but not on less stimulating beverages.


If your WLAN signal has trouble reaching as far or as many users as you'd like it to, you can boost both send-and-receive effectiveness of the wireless router by turning a beer (or soda) can into a parabolic antenna and slipping it over the router's own antenna.

It's hard to track the instructions and diagrams back to the original source; they've shown up on a million tech- and beer-positive blog sites during the past month or so, few of which linked back to the source.

Both appear to have come from a DIY project article on, which actually started as a rough draft in 2007 and has been revised 15 times since then.

Look at the actual instructions and the pics for details, but the antenna is remarkably simple:

  • All you do is cut off the top and bottom of a can, cut through one side of the remaining cylinder and bend it into a semicircle.
  • Attach the curved body of the can to the lid, which will now serve as a base, using glue or clips or duct tape or whatever is handy.
  • Attach the can-tenna to the router by slipping the upright antenna on the router though the hole in the can lid.

I've tried similar hacks using various DIY antennas and even a couple that were professionally manufactured (for which I had to pay more than the cost of a can of beer).

The biggest problems were that the power boost was never as big as I expected, and didn't always go where I wanted.

Walls continue to suck power from the signal and users outside or on the fringes of the pie-pieced arc of the antenna tended to lose connection quality rather than gain it.

The effect is also much greater if there's a metal-to-metal connection between the antenna and the router's antenna. In the diagrams the can just sits on the rubberized, insulated router's antenna.

In my various tweaks I never saw any improvement just arranging a parabola behind an insulated antenna without any contact with the metal.

When the result still isn't want you were hoping for, get a $20 WiFi repeater/signal booster and stick it halfway between the router and the outer edge of the area you're hoping to reach. In the end it's a lot easier than screwing around fine-tuning homemade antennas to make sure the signal goes exactly where it should and everyone in WiFi range gets their fare share of signal.

Read more of Kevin Fogarty's CoreIT blog and follow the latest IT news at ITworld. Follow Kevin on Twitter at @KevinFogarty. For the latest IT news, analysis and how-tos, follow ITworld on Twitter and Facebook.

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