How to Build your own Cantenna

19/11/2014 0 Comments

How to Build your Own Cantenna

Cantennas make good reference antennas. Their gain is always close to 8.5dBi. If they are correctly designed they have very low loss and so work surprisingly well.

The cans must be exactly the right diameter for them to work properly. If the can is longer, or shorter, than shown in the drawings take the measurements from the closed side.

2.4 GHz Cantenna for WiFi Bands (BandWidth is from 1.9 GHz to 2.5 GHz)
Needs a 117 x 100 mm can. Can be found originally containing such items as dog food, fruit, or potatoes.

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This connector has the right length probe and does not need to be adjusted. It is supplied with screws and nuts. SEE ITEM IN SHOP

You’ll also need a patch lead.

Maybe something like these (RP-SMA) or these (RP-TNC)

See connector identification.

Mounting the cantena can be done by screwing the base to a suitable bracket, or drilling a couple of holes
in the base to take a cable tie which can be wrapped around a pole. If the antenna is used outside, position the cantenna so the connector is at the top and add a few drainage holes (approx 4mm) on the opposite ide). Alternatively, you can paint the outside and tape cling film or plastic, preferably UV resistant, over the opening to keep out water. Injecting foam, such as for use in cavity walls or used in packaging depts into the inner is usually OK too.

Customer feedbackafter a slight initial hiccup !

I wrote back to Peter say the Cantenna decreased my signal strength. I took it apart as I had noticed that the can was in contact with the “pickup” probe. I widened the hole and now have a constant 10 db impovement over the signal strength without the Cantenna. Thanks for a cheap, practicle solution, Regards, Peter Robinson

Note: If you are using the RFShop cantenna kit, the probe is the correct length. You’ll just need to drill the holes in a can as in the diagram below: