Analysis and characterization of transponder antennae for radio frequency identification (RFID) systems

Autor: W. R. Eisentadt, Bruce A. Welt, T. C. Chau
Rok vydání: 2006
Předmět:
Zdroj: Packaging Technology and Science. 19:33-44
ISSN: 1099-1522
0894-3214
DOI: 10.1002/pts.709
Popis: An investigation into the use of various radio frequency identification (RFID) antenna designs was performed. Passive RFID tag antennae with a resonant frequency range of 902–928 MHz were tested for robustness and efficiency in the Packaging Science RFID Laboratory at the University of Florida. Commercially available single- and dual-dipole tags were examined for read performance. Electromagnetic modelling software was used to model the impedance matching and detuning effects of nearby conducting surfaces. s-Parameters, current densities and polar plots of various dipole designs were estimated. Strategies used to shorten antenna length, such as capacitive loading, were evaluated. A simple half-wave dipole antenna was modelled in order to determine the effect of length on resonant frequency and performance. Parameter sweeps showed that a length of 14.4 cm was required for resonance at 915 MHz and 50 Ω termination. Capacitive loads shortened the dipole to 8.4 cm while adding 4.2 cm to height. It was verified that a conducting surface, such as metal packaging, had strong detuning effects on RFID tag antennae. Different methods, such as tuning stubs, alleviated the detuning effects by allowing bandwidths twice as large as with a simple dipole. Finally, the rationale for commercially available RFID antenna designs was discussed. It was found that analysis of actual antenna tag structures in the laboratory and exploring different methods to improve efficiency can lead to improvements in RFID performance. Copyright © 2005 John Wiley & Sons, Ltd.
Databáze: OpenAIRE
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