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dc.contributor.advisorThiel, David
dc.contributor.authorMohammadzadeh Galehdar, Amir
dc.date.accessioned2018-01-23T02:30:59Z
dc.date.available2018-01-23T02:30:59Z
dc.date.issued2009
dc.identifier.doi10.25904/1912/2976
dc.identifier.urihttp://hdl.handle.net/10072/366547
dc.description.abstractA novel wire meander antenna is introduced for Radio Frequency Identification applications. The aim of this research was to find design rules rather than finding the best performing antenna. The limitations to small antennas performance are explored and reviewed to establish a guideline for new designs. Radiation efficiency was chosen as performance factor for measuring antenna quality. A method of moments technique based on the summation of segment currents and segment loss is introduced for finding the efficiency of wire antennas in free air. It compared favourably with two different results obtained using the finite element method (radiation pattern integration and Wheeler cap). The results were verified using two commercial available software HFSS and NEC. The efficiency of a resonant dipole was found to be proportional to the inverse square root of the conductivity. For a typical RFID meander line antenna in free space the relationship was found to be more severe. All 2D meander antennas with the same physical length in a given area were designed and simulated. The most efficient and longest electrical antennas were constructed. The simulation results were confirmed by practical measurements. A figure of merit was introduced to compare these performances with theoretical limits. Based on these antennas it is concluded that those structures with segments close to the feed have opposite current direction and usually have higher input impedance and efficiency. The idea was extended to 3D meander antennas and the same design rules as 2D meanders were used. The 3D meander antennas were placed on a conducting ground plane. Unlike 2D antennas, these antennas are capable of working near a conducting ground. This means 3D antennas are less affected by the environment around them. The two most significant shortcomings of RFID technology are: tag cost and performance. Both issues were addressed through the introduction of a new tapering method for antennas. Not only can the performance and cost be improved but the impact of tags on environment can be reduced by using this method. An optimization regime was required to find the best perform meander antenna in a given space. A Genetic Algorithm was chosen to find the best perform 2D meander antenna among all the possible solutions. A path finding optimization regime such as Ant Colony proved to be a better option. By using ACO a Pareto-Front was found for the performance of 2D meander antennas in a given area. It was shown that the efficiency is capped regardless of the track width and number of grid points mapping the area.
dc.languageEnglish
dc.publisherGriffith University
dc.publisher.placeBrisbane
dc.rights.copyrightThe author owns the copyright in this thesis, unless stated otherwise.
dc.subject.keywordsNovel wire meander antenna
dc.subject.keywordsRadiation efficiency
dc.subject.keywordsRadio frequency identification
dc.subject.keywords3D antennas
dc.subject.keywords2D antennas
dc.titleThe Space Filling Meander Antennas for RFID Applications
dc.typeGriffith thesis
gro.facultyScience, Environment, Engineering and Technology
gro.rights.copyrightThe author owns the copyright in this thesis, unless stated otherwise.
gro.hasfulltextFull Text
dc.contributor.otheradvisorO'Keefe, Steven
dc.rights.accessRightsPublic
gro.identifier.gurtIDgu1320219176486
gro.source.ADTshelfnoADT0874
gro.thesis.degreelevelThesis (PhD Doctorate)
gro.thesis.degreeprogramDoctor of Philosophy (PhD)
gro.departmentGriffith School of Engineering
gro.griffith.authorMohammadzadeh Galehdar, Amir A.


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