Multi reader/multi-tag SAW RFID systems combining tagging, sensing, and ranging for industrial applications

Author

Stelzer, Andreas ; Scheiblhofer, Stefan ; Schuster, Stefan ; Brandl, Maria

Author_Institution

Inst. for Commun. & Inf. Eng., Johannes Kepler Univ., Linz

fYear

2008

fDate

19-21 May 2008

Firstpage

263

Lastpage

272

Abstract

In this paper hardware and software aspects for the precise wireless interrogation of SAW delay line sensors by means of frequency-modulated continuous-wave (CW) interrogators are summarized. The generation of the interrogation signal as well as concepts for the frontend are treated. Advanced concepts, namely switched variants of CW based interrogators are introduced. The signal model and the appropriate maximum likelihood estimators (MLEs) for the unknown parameters are derived, as well as achievable evaluation accuracies by means of the Cramer-Rao bounds stated. Finally, a multi-antenna reader system is used for SAW interrogation by means of digital beamforming (DBF). Beside the basic DBF principles, measurement results of the interrogation of spatially separated tags will be shown.

Keywords

antenna arrays; maximum likelihood estimation; radiofrequency identification; surface acoustic wave delay lines; surface acoustic wave sensors; Cramer-Rao bounds; Multi reader/multi tag SAW RFID systems; SAW delay line sensors; digital beamforming; frequency-modulated continuous-wave interrogators; maximum likelihood estimators; multi antenna reader system; wireless interrogation; Application software; Delay lines; Frequency; Hardware; Maximum likelihood estimation; RFID tags; Signal generators; Surface acoustic waves; Tagging; Wireless sensor networks;

fLanguage

English

Publisher

ieee

Conference_Titel

Frequency Control Symposium, 2008 IEEE International

Conference_Location

Honolulu, HI

ISSN

1075-6787

Print_ISBN

978-1-4244-1794-0

Electronic_ISBN

1075-6787

Type

conf

DOI

10.1109/FREQ.2008.4623002

Filename

4623002