antenna design

Hi,
I am designing a RFID reader. Can somebody help me with the antenna design of radio frequency applications. The reader works on frequency of 135kHz and the current ratings of the antenna should be 137mA. Please let me know as to how is the antenna to be designed and what are the different types of antenna that can be designed. Also tell me about the antenna that can be built on PCB.
Thank you.

135Khz? An antenna for such a low frequency would be far too large to make as a PCB pattern antenna. Perhaps a ferrite rod with a suitable coil on it?
Try the AARL Antenna handbook for various antenna designs, perhaps you can adapt one.

Detemine who is the maker of the RFID device you are trying to design a reader for. There are plenty of antenna coil design guides available from the makers' websites.

Try websites from Microchip, Philips, etc.