A NOVEL MINIATURE MONOPOLE TAG ANTENNA FOR PASSIVE UHF RFID APPLICATIONS

A novel miniature monopole tag antenna for passive Ultra-High Frequency (UHF) radio frequency identification (RFID) operation is presented. The antenna possesses a two-sided structure that is printed on an FR4 substrate and fed by a 50-Omega microstrip line. Be properly using helical strips and vial, the antenna size can be reduced to a small volume of 10 (L) X 9.5 (W) x 0.8 (H) mm(3) to be easily integrated within various portable devices. A miniaturized quasi-lumped circuit is also designed to attain a good impedance matching between the antenna and the chip. Experimental results demonstrate that the antenna has a suitable operating band about 914-939 MHz and also quite omnidirectional radiation pattern with appreciable gain. Moreover, the proposed compact tag antenna, capable of achieving a maximum readable range of about 5.6 m with an EIRP equal to 4 W, is well suited for RFID applications. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2770-2772, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25596