Info on RFID Antenna
There are RFID system designs for 125KHz, 13.5MHz,
900 MHz band(908-915), 2.4 GHz and 5GHz.
However, balaguru, I have not seen a book dedicated
only for RFID antenna design. Over time I
have collected papers talking about antennas
in the 900 MHz band mostly from IEEE.
Some of them you can find here. A search
is your best bet since some are very
specific. Search for VHF RFID ANTENNAS.
For low frequencies(125 khZ and 13.5 MHz) is not
an antenna but a coupler. Some people like to call it
antenna but I refuse to do so, since there is not
far field radiation just magnetic coupling.
For 900 and up, the antenna, also called tag, is located
very close to the item to ID. If this item is metallic then
the antenna becomes very special, low impedance, low
efficiency, etc. Some designers use an absorber behind the
antenna for impedance purpose. One design can not fit all
since there are many kind of packaging materials(carton,
plastic, glass, metals, wood, etc). Also for 900 MHz can not
be used a microstrip antenna since the ground plane separation
is too big and render the antenna too bulky. However, 900
MHz is the band most used regarding long distance. The
band in 2.4 GHz is also used for RFID but is not very popular yet.