Performance enhancement of small antennas and applications in RFID

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Faculty of Electronics, Communications and Automation | Doctoral thesis (article-based)
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Date
2008-10-07
Department
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Mcode
Degree programme
Language
en
Pages
45, [57]
Series
VTT publications, 688
Abstract
The focus of this thesis is on the performance enhancement of small antennas and design and verification of antennas for radio frequency identification (RFID) and wireless sensors. The work is presented in eight scientific papers and in a summary, which introduces relevant fundamental concepts and previous work done in the field of small antennas. Previously, several performance enhancement methods have been proposed to improve the antenna performance especially in mobile communication applications. However, solutions for the fundamental small antenna problem, high reactive energy and low radiation resistance, which in practice lead to narrowband and low efficiency operation, are rarely provided. In this thesis, alternative methods to alleviate the high reactive energy and low radiation resistance like material loading, non-Foster tuning and multi-port loading are discussed. Also, lately antennas for RFID and wireless sensor applications have gained growing interest. However, several characteristic design features exist for these antennas. Especially, the concept of platform insensitivity is essential and discussed in detail. Also, antenna designs and dual-band tuning technique applicable to RFID antennas are presented. In addition, wireless measurement techniques for RFID antenna verification are reported.

Väitöskirjatyö käsittelee pienten antennien suorituskyvyn parantamista sekä etälukuun (RFID) ja langattomiin antureihin soveltuvien antennien suunnittelua ja mittausta. Työ koostuu kahdeksasta tieteellisestä julkaisusta sekä yhteenvedosta, jossa on esitetty pienten antennien peruskäsitteitä sekä alan aikaisempia tutkimustuloksia. Aikaisemmin pienten antennien suorituskykyä on pyritty parantamaan mm. matkaviestinlaitteissa. Kuitenkin ratkaisuja pienten antennien perusongelmaan, korkeaan reaktiiviseen energiatasoon sekä matalaan säteilyresistanssiin, jotka tekevät antennista käytännössä kapeakaistaisen ja hyötysuhteeltaan huonon, on harvemmin esitetty. Tässä työssä on analysoitu eri menetelmiä korkean energiatason ja matalan säteilyresistanssin lieventämiseen, kuten materiaalikuormitusta, non-Foster-viritystä sekä usean portin kuormitusta. Viime aikoina etälukuun ja langattomiin antureihin soveltuvat antennit ovat herättäneet kasvavaa kiinnostusta. Näissä sovelluksissa antenneihin liittyy kuitenkin useita erityisiä ominaisuuksia. Erityisesti antennien alustaepäherkkyys on tärkeää, ja sitä on käsitelty työssä yksityiskohtaisesti. Lisäksi tässä työssä on esitetty RFID-antennimalleja sekä niihin sopiva kaksitaajuusviritystekniikka. Myös RFID-antenneille soveltuvia langattomia mittaustekniikoita on esitetty.
Description
Keywords
small antennas, RFID, wireless sensors, quality factor, near-zero permittivity, non-Foster tuning, multi-port antennas, platform insensitivity, dual-band, backscattering measurement
Other note
Parts
  • M. Hirvonen and J. C.-E. Sten, Power and Q of a horizontal dipole over a metamaterial coated conducting surface, IEEE Transactions on Antennas and Propagation, vol. 56, no. 3, pp. 684-690, March 2008. [article1.pdf] © 2008 IEEE. By permission.
  • M. Hirvonen and S. A. Tretyakov, Near-zero permittivity substrates for horizontal antennas: Performance enhancement and limitations, Microwave and Optical Technology Letters, vol. 50, no. 10, pp. 2674-2677, Oct. 2008. [article2.pdf] © 2008 John Wiley & Sons. By permission.
  • M. Hirvonen, A. Hujanen, J. Holmberg and J. C.-E. Sten, Bandwidth limitations of dipoles matched with non-Foster impedances, Proceedings of the Second European Conference on Antennas and Propagation (EuCAP 2007), Edinburgh, UK, 11-16 November 2007. [article3.pdf] © 2007 The Institution of Engineering and Technology (IET). By permission.
  • J. C.-E. Sten and M. Hirvonen, Impedance and quality factor of mutually coupled multiport antennas, Microwave and Optical Technology Letters, vol. 50, no. 8, pp. 2034-2039, August 2008. [article4.pdf] © 2008 John Wiley & Sons. By permission.
  • J. C.-E. Sten and M. Hirvonen, Decay of groundplane currents of small antenna elements, IEEE Antennas and Wireless Propagation Letters, vol. 4, pp. 82-84, 2005. [article5.pdf] © 2005 IEEE. By permission.
  • M. Hirvonen, P. Pursula, K. Jaakkola and K. Laukkanen, Planar inverted-F antenna for radio frequency identification, Electronics Letters, vol. 40, no. 14, pp. 848-850, July 2004. [article6.pdf] © 2004 The Institution of Engineering and Technology (IET). By permission.
  • M. Hirvonen, K. Jaakkola, P. Pursula and J. Säily, Dual-band platform tolerant antennas for radio-frequency identification, IEEE Transactions on Antennas and Propagation, vol. 54, no. 9, pp. 2632-2637, Sep. 2006. [article7.pdf] © 2006 IEEE. By permission.
  • P. Pursula, M. Hirvonen, K. Jaakkola and T. Varpula, Antenna effective aperture measurement with backscattering modulation, IEEE Transactions on Antennas and Propagation, vol. 55, no. 10, pp. 2836-2843, Oct. 2007. [article8.pdf] © 2007 IEEE. By permission.
Citation
Permanent link to this item
https://urn.fi/urn:nbn:fi:tkk-012622