A single-sided copper clad PCB sheet - I found a 20x10cm sheet with an incomplete circuit printed on it but not etched. The print was cleaned off with wire wool.
A length of 1mm diameter bare copper wire - I found a length of mains cable and removed the earth wire.
An N-type chassis connector and an N-type to SMA adaptor.
Four nuts and bolts for attaching the N-type chassis connector to the PCB.
Drill, soldering iron, solder, pliers and your favoured nut and bolt tightening tools
Your WiFi adaptor. I use an Alfa awus036h.
For my other projects see - http://www.ecopunk.org.uk/p/projects.html
Step 1: The Antenna
You can also see the antenna constructed from the 1mm earth wire. You need to bend the wire so that it forms the diamond pattern as in the photo. Each side of the diamonds are 30.5mm. At the crossovers the wire does not touch itself.
One end of the antenna is soldered to the N-type at a height of 15mm from the collector plate. The other end is attached to one of the bolts holding the N-type chassis connector in place.
Step 2: Rear of Collector Plate
Step 3: N-type to SMA Adaptor
Step 4: Completed Double Bi-Quad WiFi Antenna
There was an improvement of signal over my previous cantenna and the supplied stick antenna.
For more of my projects see http://www.ecopunk.org.uk/p/projects.html