rfid tag documents

Dear All :
I am desiging RF tag (13.56Mhz) AFE , Now I have no experience , Does anyone have the experience or any document can share some ? Many Thanks

http://www.szforen.com/PDF/AN417.pdf
I am not sure if it helps you as you need to develop the IC or you can use any available IC like .
http://www.ic-on-line.cn/IOL/viewpdf/S4100_1303821.htm

Dear Sir:
Thanks, I have focus on RF-ID tag study , Do u have any relation document ,
Now I will design tag AFE circuit for IC , and FPGA verification. It mean I must do IC part , and I must use compomnet to finish AFE demo board for FPGA verification, DO u have any comments ? Thanks

seeeeeeee