Title
Bidirectional communication in an HF hybrid organic/solution-processed metal-oxide RFID tag
Author
Myny, K.
Rockelé, M.
Chasin, A.
Pham, D.-V.
Steiger, J.
Botnaras, S.
Weber, D.
Herold, B.
Ficker, J.
van der Putten, B.
Gelinck, G.H.
Genoe, J.
Dehaene, W.
Heremans, P.
Publication year
2012
Abstract
The ambition of printing item-level RFID tags is one of the driving forces behind printed electronics research. Organic RFID tags have been shown, initially using p-type organic semiconductors [1-4]. The introduction of n-type organic semiconductors with reasonable performance made organic CMOS conceivable [5] and organic CMOS RFID tags were shown [6]. However, all currently reported organic RFID tags are based on a tag-talks-first principle: as soon as the tag gets powered from the RF field, its code is transmitted at a data rate determined by an internal ring oscillator. Practical RFID systems will need to be able to read multiple RFID tags within the reach of the reader antenna. Existing anti-collision protocols implemented in organic RFID tags [2,4] are limited to about maximum 4 tags and come at the cost of a slow reading time. In this paper, we for the first time realize a reader-talks-first low-temperature thin-film transistor (TFT) RFID circuit. We use a complementary hybrid organic/oxide technology. As organic transistors with reasonable channel lengths (≥2μm) have a cut-off frequency below 13.56MHz, the base carrier frequency of HF communication, present technologies on foil do not yet allow to extract the circuit clock as a fraction of the base carrier. We solve this by introducing an original uplink (reader-to-tag) scheme, in which a slow clock (compatible with our transistors' speed) is transmitted as amplitude-modulation on the base carrier while data is encoded on this clock by pulse width modulation (PWM). © 2012 IEEE.
Subject
Mechatronics, Mechanics & Materials
HOL - Holst
TS - Technical Sciences
Electronics
Industrial Innovation
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http://resolver.tudelft.nl/uuid:37645b7b-f748-482f-acdf-d73b5d79e575
TNO identifier
460454
ISBN
9781467303736
ISSN
0193-6530
Source
59th International Solid-State Circuits Conference, ISSCC 2012, 19 February 2012 through 23 February 2012, San Francisco, CA, USA, 55, 312-313
Series
Digest of Technical Papers - IEEE International Solid-State Circuits Conference
Article number
No.: 6177027
Document type
conference paper