Is RFID antenna a big issue?

HI all,

I always heard about the RFID tag's main components are
uchip, antenna, and substrate. Is there anything unique
for the RFID antenna @900MHz? Is it so different from
antenna used in 900MHz GSM system?

Thx

In my opinion, the biggest difference lies at the tag antenna design. The input impedance of tag antennas is required to be small in its real part and positively large in its imaginary part, so as to match tag chips. This matching target is quite different from the traditional 50 ohm. In addition, miniaturization and wideband are among other hot issues about the tag antenna design, somewhat like the situation of any handset antenna requires.