Greetings:
I ran across this application note from Texas Instruments for a 2.4 GHz Yagi PCB directional antenna that has a 50 ohm RF interface. There is some nice simulation data and a few links to other antenna app note by TI.
http://focus.ti.com/lit/an/swra350/swra350.pdf

_________________
- Kirt Blattenberger
RF Cafe Progenitor & Webmaster