By Topic

Mixed orthogonal frequency coded SAW RFID tags

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$31 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Gallagher, M.W. ; Electr. Eng. & Comput. Sci. Dept., Univ. of Central Florida, Orlando, FL, USA ; Malocha, D.C.

Orthogonal frequency coded (OFC) SAW radio-frequency identification (RFID) tags are currently being explored as a multi-sensor platform because of their passive spread-spectrum operation, low loss, and resilience in harsh environments. Ongoing research continues to search for robust device embodiments that increase the number of identifiable codes, in the presence of intersymbol interference, while maintaining reasonable device lengths. This paper presents a technique that shortens the SAW response length while preserving code diversity and bandwidth by utilizing a multi-track SAW configuration. These new devices allow the time response of multiple OFC chips to overlap and yield a mixed-frequency chip having the sum of the chip bandwidths but shorter overall time response. The theoretical development is presented and examples are discussed for these new mixed orthogonal frequency coded (MOFC) SAW devices. Experimental results for MOFC sensors, fabricated on YZ-LiNbO3, with a 7% fractional bandwidth and five chip frequencies in three cells, provide a good contrast to similar OFC designs. Experimental results are presented for the simultaneous operation of eight wireless temperature sensors-four OFC and four MOFC-in a 915-MHz wireless correlator receiver system, highlighting the ability of these devices to operate in the same system.

Published in:

Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on  (Volume:60 ,  Issue: 3 )