simplest rf id

hello, I hope to make a simple rfid that can transmit 20 different frequencies and receiver that can decode those signal transmitted from rfid. I hope that rfid without any transistor so i can design it very small I don't need it long range. I hope max 10 meter range. please post your Idea

I think you may misunderstand "RFID" - do you mean a system for remote control of something?

RFID usually means something like a contactless door entry keyfob or card, contactless bank cards and such, which only work within a few centimetres of the "reader" unit.

Ten metre range means an active, battery powered transmitter of some sort. By 20 different frequencies, do you mean 20 different commands to do different things?

Can you give more details of what you are trying to do with such a system?
I'm guessing from your other posts it may be something to do with controlling a robot?