Help me design an Antenna

hey guys
i am trying to design a small loop antenna (rectangular one) to work at 434 MHz and have an input impedance of about 4-8KOhms.

I tried it but ended up with having an impedance of 40KOhms. Can any one of you guys help me design one at that freq and impedance.

I need the antenna size to do the layout in an FR4 PCB .

Please guys i am not an RF guy but i am stuck with part to finish my design for encrypted sigital FSK transmitter.

thank you.

http://www.maxim-ic.com/appnotes.cfm/an_pk/3401

pl post the sketch ...I ll try