DESIGN OF A WIDEBAND RECTANGULAR LOOP TAG ANTENNA FOR UHF RFID LIBRARY MANAGEMENT

Abstract

In this letter, we propose a wideband rectangular loop tag antenna for ultra-high frequency radio frequency identification library management systems. The proposed antenna has a small matching loop for conjugate impedance matching with the impedance of a tag IC. The impedance bandwidth of the proposed antenna is broadened by lengthening the vertical sides of a rectangular loop. We considered the effects of books in designing the tag antenna. The optimized tag antenna, which is 35 HMI X 90 nun in size, has a wide impedance bandwidth of 170 MHz for SI, less than 10 dB. The maximum reading distance of a single tag is about 5 in, and the concurrent reading distance of 19 arranged tags is 1 in.