Minimum components for RFID system

Hi all,

im trying to design a RFID 125kHz system that only recognises one passive tag, with an output to show the tag is recognised. Could someone suggest or point me in the direction of the minimum numbers of components i would need to create this application? im hoping to an as small as possible PCB with separate antenna.

Thanks in advance
nodee

http://ww1.microchip.com/downloads/e...doc/51115f.pdf

thanks samba077, some questions though.. ive been looking at the MCRF200 from the data sheet you linked to and i am unsure what the IC can do for me. the MCRF200 is described as having various RFID features but is also shown in a diagram (bottom of page 9) as a tag of some sort. please could you clear up what exactly the function of this device is and how this would apply to the application i described in the original post?
Sorry if im being a bit thick im new to this and have got myself confused. thanks for your time.
nodee

Does anyone have any ideas on this? most of the rfid systems ive seen seem to be for large scale or multi tag applications which are a bit excessive for my needs. im only after a system that will read a single tag and tell me yes or no if it is the one I have stored in memory. Is there a short cut solution that will cut out the need for over complicated chips and programming etc? thanks
nodee

These work as RF transponders.. they are used to modulate the signal received from the coil when a card is swiped and electromagnetic energy is generated.. these waves need to be formatted into electrical signals for further understanding of the controller device..