How To Build A Tin Can Waveguide Wifi Antenna
Want to increase your wifi wireless network range with out splurging much? A tin can waveguide wifi antenna is all you want. It will take not more than $5 US and an empty juice or drink/food tin can. Here is an idea that really works.
• A N-Female chassis mount connector – A connector whose one side is N-female to connect the cable with your wireless equipment and the counter side has a small brass stub for soldering on wire. You can easily find it on any electronics stores internet suppliers.
• 4 Small Bolts & Nuts – Big enough to go through the can and the connector. It is recommended to use stainless bolts and nuts. If your N-connector is already a screw on type, then nuts and bolts are not required.
• Wire – A 12 gauge copper wire of about 1.25”. The wire will stick into the brass stub in the N-connector.
• A tin can – This is quite interesting to find a can about 3″ and 3 2/3″ in diameter. The size can differ and does not have to be exact. The cans that work better include coffee cans with diameter of 6” or can of 39oz. Pringles can fall short of size and don’t work well. However if you still want them, then try looking for a can as long as possible.
Once you have collected all the parts, you antenna will be ready in next two steps that involve: drilling holes in the can to mount the probe and assembling the probe mount in can.
• Drill the holes in the can
The connector assembly will mount in the side of the can. The holes should be placed in the right position and place to mount the N-connector. This step is quite important and be careful while you place the hole and connect. The location can be derived from the formulas that use the frequency that the antenna will operate at and the can diameter.
You can use this calculator:
The calculations above are based on a 3.25 can diameter to calculate different diameters please go to the link below.
You just need to enter the diameter of the can and hit the calculate button. 802.11b and 802.11g wifi networking equipment operates at a range of frequencies that range from 2.412 GHz to 2.462 GHz. It would be better if your can is longer than the ¾ Guide Wavelength.
Now mark the location on the can where you are going to punch a hole for the connector. The 1/4 Guide Wavelength digit guides you how far from the bottom metal of the can to mark the centre of the hole. Empty your can and wash it properly after removing the label. Use a scale to measure the length from the bottom level and mark a dot.
You can also use your drill machine if you have it. But make sure the size of your drill matches the size of the centre of the connector. You can also use hammer and nail. If you plan to use bolts on connector then make 4 holes for the bolts. Use your connector as a drilling guide.
• Assemble the prone and mount in can
Now you require a bit of wire and a soldering iron with a friend or a helper. Cut the wire in a way so that when it is stuck in the connector, the total length of both the brass tube and wire sticking out past the connector is about 1.21″. Try to be closer to this length.
Once you have got the correctly sized wire, solder it into the connector keeping it as straight and upright as possible. Then screw or bolt the assembly into your can when it is cooled. Keep the heads of the bolts inside the can and the nuts on the outer side to reduce the obstructions for the antenna. You are almost done.
• The final step is to connect your antenna to the wireless access point
You will require a special cable which is generally known as “Pig Tail”. The pig tail will help in connecting the wireless card with your antenna. One end of the cable will have a “N” Male connector which is just correct for your can-tenna and the other end will have a connector which is just right for your card or access point.
You will also require a wireless NIC or access point that has external antenna connector. Or else you will have to hack into the one you have to hook up the cable. Try this procedure only if you are good at soldering iron and electronics. For ease, you can try Agere Orinoco cards that have a nice antenna connector.
Finally hook up your cable and point it towards your friend’s to see how far the network is being stretched.
• This antenna involves linear polarization and it’s rotation will affect the strength of your signal. So it matters how you rotate the antenna. Try putting the connection straight down.
• Do it at your own risk.