Mar 18

WRITTEN BY: Peter Martin
Friday, March 18, 2011 

Cantennas make good reference antennas. The gain is always close to 8dBi.

They are also useful as feeds for grid antennas, or solid dishes. The 5.8Ghz feed is particulary useful with ex-satellite dishes.

We sell the designs below as CANTENNA KITS You just need to supply your own can and drill the holes.

2.1GHz (3G and Virgin Broadband network)  to 2.45GHz (Wireless 802.11 b, g)
Note: You'll also need a patch lead. For Virgin BB we'd recommend N30MC39-LMR100-1500 (1.5 mtrs long) A further extension can be used but we'd recommend a maximum of 5 mtrs. N30N80-JBY195-5000 or N30N85JBY195-5000 For wireless use (802.11 b,g, n) with Netgear, D-Link , which use RP-SMA connectorsN30A60-JBY195-2000  (2 mtres) or N30A60-JBY195-5000  (5 mtres) (Just type N30A60 into search box)  For Linksys (they mainly use  RP-TNC connectors) N30T60-JBY195-2000  (2 mtrs) or N30T60-JBY195-5000  (5 mtrs) Just type N30T60 into search box)  See under 'FAQ' for connector identification. The can must be exactly the right size for it to work properly. This is a very common size and was originally full of peaches! 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. 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 pakaging depts into the inner is 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. I have decided to commit to VBB now as this ensures a truly BB experience. Thanks for a cheap, practicle solution, Regards,  Peter Robinson Note: If you are using the RFShop cantenna kit, the probe is already soldered to the correct length. You'll just need to drill the holes in a can as in the diagram below:
Field Plot of 2.45GHz Cantenna. The above design was analysed by CST's MWS program. Plot below is courtesy of CST. www.cst.com   3.5GHz ( 'Unwired' Network)
5.8GHz (Wireless 802.11a)
VSWR Plot of 5pG cantenna