HW projects - WLAN directional antenna (cantenna)

This cantenna was originally constructed to extend the range of the webcam server WLAN connection and worked pretty well, but became unnecessary when I acquired a new USB WLAN dongle (A-Link WL54USB-A) for the camera setup that already had an external antenna and was powerful enough to work reliably over long distances. This thing is now being used for general WiFi "troubleshooting" and afternoon spying :)

All information that was needed for dimensioning and calculating everything correctly was found by googling around.

Some links:

http://en.wikipedia.org/wiki/Cantenna
http://www.educypedia.be/electronics/Wlan-antenna/wlan-antennas2.htm
http://flakey.info/antenna/waveguide/
http://www.turnpoint.net/wireless/cantennahowto.html
http://kismac.macpirate.ch/wiki/doku.php?id=dwl-g122
http://foro.elhacker.net/index.php?topic=163226.msg770638


Materials used:

-Stainless steel vacuum flask, open end sawn wider and the inner container removed
-BNC chassis connector with a soldered in bare copper wire (antenna element)
-BNC plug with a RG174 coax pigtail cable
-D-Link DWL-G122 C1 USB WLAN adapter, modded to accept external antenna
-Extendable tripod stand that i dug from the trash bin
-5 meter USB extension cable
-Misc fittings, screws and straps

(click for larger image)



inside the can



the whole thing