First I wish to say that I build and tested this antenna, and I was SURPRISED – how this small device is able to work so good! This small antenna outperform my other two homebuilt 14dbi wifi panels.
I used two one sided pcb to create this, but on the zero forum there are pictures where only thin metal sheets are used, and it works again.
The diameter of the circle is equal to the half wave light of the 2.4ghz wifi band or 62mm , so this antenna may be recalculated for other /5ghz/ frequencies.
Now antenna INFO :
Name of Antenna, model : SMCANT-DIFP11
Data sheet can be found on this link : http://www.smc.com/files/AP%5CDS_ANT.pdf
Frequency : 2.400 – 2.500 GHz
Gain : 11 dBi
VSWR : < 1.22
POLARIZATION : Circular
BEAM WIDTH • Horizontal: 70° • Vertical: 70°
IMPEDANCE • 50 Ohms
DIMENSIONS • 25 x 102 x 102 mm
So here is the interesting part – this one is found disassembled on www.zero13wireless.net
Link to the forum www.zero13wireless.net
Very small! Great results!
Dimensions of the reflector are 105×105 mm
8 mm gap between two metal plates of the “circle” and the reflector.
Here are my test whit this antenna – the original test was for other but I need something to compare :
http://www.digdice.com/2007/05/17/d-link-ant24-1200-sector-panel-antenna/
Here is the way to stack two of these homebuilt antennas together : http://www.digdice.com/2007/08/10/httpwwwdigdicecomwp-adminpost-newphp/