Compact printed-on-CD UHF RFID tag antennas

In this paper, we present custom design of UHF RFID tag antennas for the identification of stacked in a package CDs. The main challenge of such a design has been the size minimization of the antenna elements since the tag is allowed to occupy a circular area of 33.5 mm in diameter on the central part of an actual CD free from metallization. At the same time, tag antennas have been optimized for the required direct complex impedance matching with the IC chip.