Hybrid time/phase/frequency domain linear electromagnetic encoders for displacement sensing and near-field chipless-RFID
Karami-Horestani, Amirhossein (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)
Paredes, Ferran (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)
Martín, Ferran (Martín Antolín) (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)

Date:	2024
Abstract:	Hybrid time/phase/frequency domain linear electromagnetic encoders are presented in this paper for the first time. The encoders consist of a linear chain of electric-LC (ELC) resonators etched in a dielectric substrate. Encoding is achieved by phase and frequency modulation simultaneously, namely, by considering different transverse positions and dimensions of the ELC resonators in the chain. The reader is a simple matched microstrip transmission line terminated with a matched load, and encoder reading proceeds by displacing the encoder over the reader line, at short distance, in the direction orthogonal to the line axis. When an ELC resonator lies on top of the line, the phase of the reflection coefficient at resonance depends on the distance to the input port and hence on the transverse position of the resonator in the chain (phase modulation). Moreover, the size of the resonator determines its resonance frequency (frequency modulation). This means that the reader line should be fed by as many harmonic signals as ELC resonator sizes considered, to identify the phase and the resonance frequency of the inclusion (ELC) on top of the line. In this paper, we consider 16 different transverse positions and 4 different sizes of the ELC resonators, which are read sequentially, in a time-division multiplexing scheme. Thus, 6 bits per encoder position (or row) in the chain are achieved. These encoders, with a per-unit-length density of bits of DPL = 6 bit/cm, can be applied to the implementation of synchronous near-field chipless-RFID systems with high data capacity, as well as long-range displacement sensors. In the latter case, the number of bits per encoder row can be doubled (i. e. , 12 bits) by considering two chains and two readers, allowing for the discrimination of 212 (= 4096) absolute positions.
Grants:	Agencia Estatal de Investigación PID2022-139181OB-I00 Agencia Estatal de Investigación PDC2021-121085-I00 Agencia Estatal de Investigación PRE2020-093239 Agencia Estatal de Investigación PID2019-103904RB-I00 Agència de Gestió d'Ajuts Universitaris i de Recerca 2021/SGR-00192
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Chipless-RFID ; Electromagnetic encoder ; Microstrip technology ; Motion control ; Phase/frequency modulation ; Position sensor
Published in:	IEEE journal of radio frequency identification, Vol. 8 (2024) , p. 134-144, ISSN 2469-7281

DOI: 10.1109/JRFID.2024.3366309

Available from: 2026-02-28 Postprint

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Engineering > CIMITEC-UAB
Articles > Research articles
Articles > Published articles