The original instructions have disapperared, the Wayback Machine crawled it, but does not show anything im my browser right now…
Anyway: The dimensions for a proper WLAN biquad antenna should be available somewhere out there.
Our Problem was, that we needed WiFi on 3rd as well as 1st floor, the solution was a router with external antenna. The hardest thing to get was the proper coax-connector (
SMA? Reverse SMA ? , Amphenol RSMA1111A1-3GT50G-1-50 for my TP-Link router ) and the smaller-than-TV-cable (RG58B). You maybe better off buying a „WiFi-Cable“ (antenna cable) on eBay and cutting it in half, which avoids the crimping. The rest is single sided PCB (the semi-finished stuff you need to etch or mill your circuit boards), some solid wire (in Germany: salvaged NYM-something), a pin from a CD spindle (sewed off to get a pipe), hot melt and something to hold everything to point in the right direction.
The latter was not a problem for me: I put in on the floor of the attic to radiate down.
(Original Post: http://www.metalforum-owl.de/viewtopic.php?f=21&t=138&start=20#p16568, Aug. 15th 2009)