Introduction: Fast, Cheap, and Easy Wifi Cantenna

Picture of Fast, Cheap, and Easy Wifi Cantenna

This instructable is on how to make a wifi wave guide antenna for FREEEEE! (Assuming you already have a few things.) 

Step 1: Materials

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Can (I just used a #10 can)
USB WIFI dongle
USB extension cord (my dongle came with one)
That's it.

Step 2: Cut

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Cut a hole in the can towards the bottom (see picture) just big enough that you can force the female end of the USB extension cable in. I just stabbed mine with a pocketknife a few times. You don't want the cord to be able to move around at all. If you make the hole too big, just wrap the end of the cable that you sticking in the hole with duck tape until it's hard to fit in.

Step 3: Plug In

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Plug the dongle into the extension cord and the extension cord into your computer.

Step 4: Enjoy Cats, Violence

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It will take some aiming and maybe even a tripod but you should definitely  notice an increase in the bountifullness of your internets.
I went from 1-2 bars to 4 bars and I can play games with  no network lag. I am not even in the house, but in an outbuilding. Also I am using a crappy $5 wifi dongle. Hope this helps someone!


Greasetattoo (author)2011-08-18

Would mounting to the top of my house make a big difference?
Higher up, better??

As, there is a school about block away from my house.
My laptop the way it sits, does not pick it up!

RobinB60 (author)Greasetattoo2017-04-09

Line of sight will most def improve performance, if that's what you mean. Further away means less ability to travel through walls.

You might be able to pick it up, I pick up a couple from around 200 yds away, but as for on your roof, usb cables aren't meant to go more than like 6 feet I think.

USB's max is around 18 feet... thats why the longest USB cable is only 16 feet

Sounds4cc (author)gburnaska2011-08-23

I have successfully coupled 2 - 16 footers and a 6 footer together from my laptop to an electronic flow monitor. worked fine.

gburnaska (author)Sounds4cc2011-08-23

no doubt you can go longer.... just not if you want speed.... try 35 feet to a HDD and transfer a 2 gig file.... if you want any chance in keeping the 480 speeds you should use a repeater

pcooper2 (author)gburnaska2011-08-24

Not likely to work. USB works by the host (computer) polling devices on the bus. Responses from devices need to arrive back at the host within a certain length of time. At about 1 nanosecond per 9 inches of cable, exceeding the maximum cable length allowed by the USB specification even by a couple of feet is likely to cause communication over USB to fail.

For USB 2.0 or earlier, the maximum length of a standard cable is 5 metres (16.4041995 ft). For 3.0 there's no exact number but we figure 3 metres (9.84251969 ft).

sdobbie (author)psykopenguin2011-08-21

You can get a USB cable much longer than that if you use active repeater extender cables. I got a 5 meter on off ebay which works with everything except external hard drives.

psykopenguin (author)sdobbie2011-08-21

Well you could do that but it's not really so much a single cable at that point anymore much like USB over CAT5(e) but you are correct that you could technically go beyond that point. :)

sdobbie (author)psykopenguin2011-08-21

So how can cat5 cables be hundreds of meters long but usb cables stop working after a few meters?

pcooper2 (author)sdobbie2011-08-24

USB cables work fine over hundreds of meters, but the communications scheme does not. The host polls devices on the bus and according to the standard they are expected to respond to the host within an allotted time. The electrical signal propagates along the cable at something close to the speed of light, about 1 nanosecond per 9 inches of length. Exceeding the maximum allowable cable length even by a couple of feet will delay the communications enough to cause timing errors, i.e., communications failure.

eleers (author)sdobbie2011-08-21

Cat5 cables can only be 100 meters... you start losing signal due to interference and electrical resistance after that. Fiber cables are faster and can be much longer, but they're way more expensive.

The "spec" for USB2 is 6 METRES! I'm currently using a wifi connection to my hotel with a 6m cable to put my USB adapter in a better position to receive the distant hotel AP (other end of the corridor)

Might give this "cantenna" a try too though.

probably, but wifi isnt usually that strong, and since so many schools have the wifi in the center, and have really thick walls, i say probably not.

derekiswise (author)2014-06-01

What if i used an old tv/ satelite dish and mounted the usb network adapter in the center of that?

I happen to have a few laying around i could use for this exact purpose!

RobinB60 (author)derekiswise2017-04-09

I think that could work very well provided you point it in the right direction. A hot glue gun will come in handy. I plan on trying this exact thing. I might even mount it on a pole outside, which means extra work to waterproof it.

Chad Baxter (author)2013-04-02

Don't touch the can...six volts of electricity flows thru that USB dongle. It would be best if you insulate it

Skallywag707 (author)Chad Baxter2016-10-18

This is an ancient ible, but 6 volts is not harmful to touch at all. idk how many amps, but since it is a usb dongle, probably very few. Nothing to worry about whatsoever...

cenaadel (author)2014-07-20

greaaaaaaaat job !!!! please can you help me to make a cantenna for cdma evedo

1.9 ghz ?????? !!!!!!!

cenaadel (author)2014-07-20

greaaaaaaaat job !!!! please can you help me to make a cantenna for cdma evedo

1.9 ghz ?????? !!!!!!!

maurya bambaj (author)2014-07-05

this idea is very good but hoe will it work if tis is an laptop

Newton4 (author)2014-02-28

it would be better if you used a can without those ribs

Amey Joshi (author)2013-12-18

nice instructable !! but can you tell me, from where did you bring the Dongle?

manutea (author)2013-08-07

Nice project, you could hurt yourself very seriously if not using proper tools to cut the metal

mmtubera_1221 (author)2013-06-11


talhaijaz (author)2012-10-20

wow! it is good i like it

ederfel (author)2011-08-21

This article has some very useful information about can dimensions and other aspects which affect the gain:

In particular, it advises smooth sided tins, and using a wire to avoid excessive intrusions into the tinspace.

XboxModz (author)ederfel2012-04-26

Yes. SMOOTH is best. My latest Cantenna (I have experimented with a lot of different can sizes/types) is the best one that I have built to date. It has smooth sides (no ripples). It was an X-mas cookie container that measures 3" Dia x 10" Long. PERFECT for a Cantenna.

I didn't use any dongle tho. I built it the traditional way using the "N" female chassis mount connector and copper wire probe.

knownassociate (author)2012-01-10

In reading the comments I saw several questions regarding the exact placement of the usb stick. This is a link that will calculate that for you according to the measurements of your can

That site refers to a cantenna made to connect to a wifi card installed into a pc, but as it worked well, the two must not be too dissimilar.

Douglas 99 (author)2011-10-12

Found that this #10 USB Cantenna works great, found that it work even better if you add another #10 can to it, just cut out the bottom and duct tape it on, or hot glue gun works good also. Even better directional signal for me! Make sure you slowly rotate around the neighborhood, you will be amazed what this pulls in. I pull in 3 signals without the Cantenna, I can pull in about 30 when I put the same dongle into the cantenna, I put it about an inch (2.5cm) off the bottom of the can just like in the above picture, But my USB case is NOT removed. Also the higher you can mount it the more or better signal pulls in., mine works better on the second floor pointed out the window. Roof mount even better, make your mast so you can rotate the cantenna. also plastic lid on the open end helps to keep it weather proof. anyone find any other improvements let me know, I love this Cantenna, it is simple and easy.

lnascimento2 (author)2011-08-25

Worked fine! i've upload the image of the result of my wifi cantenna.

i see that your can is cut open, so i assume if i do that itll work like this, |_ -->, so the line going up represents the tin can that is left there, and the side that is open is were the wifi is directed?

pgwbali (author)2011-08-22

I live in Bali and use a wireless modem (uses a SIM) would this instructable increase the signal strength?

pcooper2 (author)pgwbali2011-08-24

Yes, in a way. It doesn't increase transmitter power or receiver sensitivity, but it concentrates the available power into a narrow, directional beam that can reach farther than the omnidirectional antennas used in most Wi-Fi gear.

skrubol (author)2011-08-24

You don't mention any measurements in this. Logically you want the antenna part of the dongle to be in the middle of the can, but the distance from the back is important.
IIRC 1/4 wavelength is optimal (or is it 1/2 wavelength?) For 2.4 GHz this is about 3cm (or 6cm.)

cournal (author)2011-08-18

this is fantastic!!
will this work for the itouch 4g aswell? i'm trying to figure out how i can get wifi in my itouch wherever i go. im addicted to the google maps and i wan to know where i am and ofcourse using texting app.

iScience (author)cournal2011-08-18

Maybe you can but you have to use ipod touch inside the coffee can which will be annoying...

urbanpirate (author)iScience2011-08-21

perhaps a much bigger can is in order?

iScience (author)urbanpirate2011-08-22

If you flip the ipod and on the top (corner) you will see a black plastic, thats WIFI
sensor, to encrease its range, I think we have to make a aluminum cone of some kind and attach it to the sensor

KB7GP (author)iScience2011-08-22

Oops.. sounds like the old tin foil around the Rabbit Ears gag. :)

iScience (author)KB7GP2011-08-23

kkk maybe you can disassemble the ipod and attach a wifi antanna then drill a hole in the alumium caseing and put it back on. Maybe it will increase its range :)

cournal (author)iScience2011-08-23

I was thinking of doing just that But i'm going to wait for my 1 year warranty to expire before i open my itouch :)
I even thought of cuting out the apple logo and placing EL wire inside so it can light up when i turn on my ipod. That would be pretty cool.

iScience (author)cournal2011-08-23

I guess you have professional soldering skills becuase in ipod touch, you need to solder with SMT(Serface Mount Tecnique).

cournal (author)iScience2011-08-23

Yeah that would be pretty frustrating.

nclarke (author)cournal2011-08-19

What's an itouch 4g? :S

cournal (author)nclarke2011-08-23

Ipod touch 4th generation is a music player from apple that is very similar to the iphone 4. Its mainly for music but you can download apps whenever you have wifi available.

orcrush (author)nclarke2011-08-20

It's a 4th generation ipod touch.

Jimmy Lieb (author)cournal2011-08-21

well, no. the ipod touch does use wifi, but it only will work where wifi is available. this will extend the range, but not that much.

fmeow (author)2011-08-22

What kind of speed do you get using this method? and why did you remove the plastic cover of the wifi dongle?

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