I have made the following WiFi antennas:
Made two, same design for both.
Gain is good: ~12dB.
Using your average Chinese wok and a USB WiFI adapter.
(Oh the fun I had making the adapter work under Linux:
I ended up contributing to the kernel driver.)
Spent so much timing cooking up the software,
I never got around to building the hardware properly!
Made from tiny little copper sheets.
Haven't finished this either as the surfaces are still
to dirty to solder on (need to clean them again).
I plan to conduct a distance test by using both cantennas.
As there is line-of-sight between the top floor of my uni's library and
my appartment block's roof, I'll set up one can with my superpowered AP
and the other with my laptop at uni.
Now only issue is aiming them at each other...
Ashley doing the honours while I shoot in the rain:
(we were conducting a range test by streaming video from my room
and moving as far away from it as possible)