miun.sePublications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Microstrip Antennas for Remote Moisture Sensing using Passive RFID
Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media.
Mid Sweden University, Faculty of Science, Technology and Media, Department of Information Technology and Media.
2009 (English)In: APMC: 2009 ASIA PACIFIC MICROWAVE CONFERENCE, VOLS 1-5, IEEE conference proceedings, 2009, p. 2375-2378Conference paper, Published paper (Refereed)
Abstract [en]

The paper presents how materials with a highability of absorbing moisture can be used with microstripantennas and passive RFID chips for constructing remotely readmoisture sensors. The concept is based on pairs of microstripantennas, applied on the same piece of PCB and each equippedwith one RFID chip, where one antenna is covered by themoisture absorbent material and the other is left open. In ahumid or wet environment the moisture concentration is higherin the absorbent material than in the surrounding environmentwhich causes degradation to the embedded antenna both interms of dielectric losses and change of input impedance. Thelevel of relative humidity or the amount of water in theabsorbent material is determined for a passive RFID system bycomparing the difference in RFID reader output power requiredto power up respectively the open and embedded tag. While ithas previously been shown how this can be accomplished withsimple one-layer antennas we here look into using microstripantennas to get around the problem with high influence frombackground material. Typical applications include moisturedetection in buildings, especially from leaking water pipeconnections hidden beyond walls or simply to measure the levelof relative humidity at hidden locations.

Place, publisher, year, edition, pages
IEEE conference proceedings, 2009. p. 2375-2378
Keywords [en]
RFID, Moisture Sensors, Antennas
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:miun:diva-10381DOI: 10.1109/APMC.2009.5385463ISI: 000279924301178Scopus ID: 2-s2.0-77950638716ISBN: 978-142442802-1 (print)OAI: oai:DiVA.org:miun-10381DiVA, id: diva2:278039
Conference
Asia Pacific Microwave Conference 2009, APMC 2009; Singapore; 7 December 2009 through 10 December 2009
Projects
STC, RFID Gränsgångare, Paper Four, PriMeBits, NorditeAvailable from: 2009-11-23 Created: 2009-11-23 Last updated: 2013-09-19Bibliographically approved
In thesis
1. Antenna-based passive UHF RFID sensor tags: Design and application
Open this publication in new window or tab >>Antenna-based passive UHF RFID sensor tags: Design and application
2013 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

RFID, as a low cost technology with a long life time, provides great potential for transmitting sensor data in combination with the ordinary ID number. The sensor can, for example, be integrated either in the chip or in the antenna of an RFID tag.This thesis focuses on the design of antenna-based UHF RFID sensor tags as wireless sensors at the lowest possible cost level compatible with standard communication systems in logistics. The applications of the sensor tags, in this work, mainly target remote humidity sensing. Antenna-based sensory UHF RFID tags utilize the influence that the physical or chemical parameters to be sensed have on the electrical properties of a tag antenna. The variations of the electrical properties of the tag antenna can be measured in many ways. In the thesis, a description is provided as to how these variations are normally measured by an RFID reader without any other assistant equipment. Three structures of antenna-based RFID sensor tags are presented with detailed characterizations. The first one utilizes the sensitivity of the antenna to the surrounding environment to construct RFID sensor tags, where a moisture absorbing layer providing wetness/humidity sensor functionality is placed on the RFID tag antenna to increase the humidity concentration surrounding the tag antenna and the thesis describes how to overcome certain limitations due to disturbances associated with background materials. The second structure directly integrates a small resistive sensor element into an RFID tag antenna and the sensor information can thus modulate the antenna performance by means of galvanic contact. The third structure embeds a small resistive sensor element into a loop which is positioned on top of the tag antenna and the sensor information can thus modulate the performance of the tag antenna by means of electromagnetic coupling. Both theoretical analysis and fullwave simulations are presented for the latter two sensor tag structures in order to characterize the performance of the sensor tags. An ultra-low cost printed humidity sensor with memory functionality is also designed and thoroughly characterized for integration into RFID tag antennas by means of galvanic contact or electromagnetic coupling. The sensor is a 1-bit write-once-read-many (WORM) memory printed using conductive ink. The WORM works as a pure resistive humidity sensor and can provide information about an historical event. The WORM sensor is presented by introducing its geometry, characterizingits behavior in humidity and explaining the principle of the humidity effect. The WORM sensors are also integrated into the RFID tags by means of both galvanic contact and electromagnetic coupling in order to experimentally verify the two concepts. To lower the cost of the RFID tags, the antennas are normally printed, milledor etched on flexible substrates using low-cost high-speed manufacturing methods which in some cases cause a high degree of edge roughness. The edge roughness will affect the behavior of the antenna, however, the characteristics of edge roughness on RFID antennas have previously not received any significant attention. Unforeseen antenna behavior can affect the antenna-based sensor tags, thus the influence of edge roughness is also investigated in the thesis.

Place, publisher, year, edition, pages
Sundsvall: Mid Sweden University, 2013. p. 84
Series
Mid Sweden University doctoral thesis, ISSN 1652-893X ; 157
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:miun:diva-19889 (URN)STC (Local ID)978-91-87103-99-5 (ISBN)STC (Archive number)STC (OAI)
Public defence
2013-06-18, Sundsvall, 13:15 (English)
Opponent
Supervisors
Available from: 2013-09-19 Created: 2013-09-19 Last updated: 2016-10-19Bibliographically approved

Open Access in DiVA

No full text in DiVA

Other links

Publisher's full textScopus

Authority records BETA

Sidén, JohanGao, Jinlan

Search in DiVA

By author/editor
Sidén, JohanGao, Jinlan
By organisation
Department of Information Technology and Media
Other Electrical Engineering, Electronic Engineering, Information Engineering

Search outside of DiVA

GoogleGoogle Scholar

doi
isbn
urn-nbn

Altmetric score

doi
isbn
urn-nbn
Total: 689 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf