RFID Coverage Extension Using Microstrip-Patch Antenna Array [Wireless Corner]

Author

Abbak, Mehmet ; Tekin, Ibrahim

Author_Institution

Dept. of Electron. Eng., Sabanci Univ., Istanbul

Volume

51

Issue

1

fYear

2009

Firstpage

185

Lastpage

191

Abstract

In this paper, a UHF-band 2 times 2 microstrip phased-array antenna is designed and implemented to extend the coverage of an RFID reader system. The phased-array antenna has four microstrip-patch antennas, three Wilkinson power dividers, and a transmission-line phase shifter. These are printed on a dielectric substrate with a dielectric constant of 4.5. The array has dimensions of 34 cm times 45 cm, operating at a frequency of 867 MHz, as specified in RFID Gen2 protocol European standards. The phased-array antenna has a measured directivity of 12.1 dB, and the main-beam direction can be steered to angles of plusmn 40deg, with a HPBW of 90deg. The phased-array antenna is used as the receiving antenna in a commercial reader system. Experimental results indicate that the coverage of the RFID system with the phased-array antenna is superior to the coverage with a conventional broader-beamwidth microstrip-patch antenna. The proposed system can also be used for a wireless positioning system.

Keywords

UHF antennas; microstrip antenna arrays; permittivity; power dividers; radiofrequency identification; receiving antennas; RFID Gen2 protocol European standards; RFID reader system; UHF-band microstrip phased-array antenna; Wilkinson power dividers; broader-beamwidth microstrip-patch antenna; dielectric constant; dielectric substrate; frequency 867 MHz; receiving antenna; transmission-line phase shifter; wireless positioning system; RFID; UHF antennas; array antennas; identification; microstrip antennas;

fLanguage

English

Journal_Title

Antennas and Propagation Magazine, IEEE

Publisher

ieee

ISSN

1045-9243

Type

jour

DOI

10.1109/MAP.2009.4939065

Filename

4939065