Rfid antenna design, software,

Dear all,

i am working on designing a spiral rectangular antenna for a tag, but i have a few questions:

which software do i use ?
is the antenna normally in the form of a wire ?
do i need to buy a chip for the antenna to form the tag ?

operating freq: 13.56mhz
range.. short.. 1-2 m
dimensions, credit card.. 40 by 35 mm

please help me identify the software needed for the design of rectangular spiral antenna...

I am also looking for the same please reply!

an example here:


RFID Transponder operating at 13.56 MHz

http://www.cst.com/Content/Documents...008_online.pdf