The main objective of this research is to design, model and implement several antenna
geometries using electromagnetic band gap (EBG) material and a defected ground
plane. Several antenna applications are addressed with the aim of improving
performance, particularly the mutual coupling between the elements.
The EBG structures have the unique capability to prevent or assist the propagation of
electromagnetic waves in a specific band of frequencies, and have been incorporated
here in antenna structures to improve patterns and reduce mutual coupling in multielement
arrays. A neutralization technique and defected ground plane structures have
also been investigated as alternative approaches, and may be more practical in real
applications.
A new Uni-planar Compact EBG (UC-EBG) formed from a compact unit cell was
presented, giving a stop band in the 2.4 GHz WLAN range. Dual band forms of the
neutralization and defected ground plane techniques have also been developed and
measured. The recorded results for all antenna configurations show good improvement
in terms of the mutual coupling effect.
The MIMO antenna performance with EBG, neutralization and defected ground of
several wireless communication applications were analysed and evaluated. The
correlation coefficient, total active reflection coefficient (TARC), channel capacity and
capacity loss of the array antenna were computed and the results compared to
measurements with good agreement.
In addition, a computational method combining Genetic Algorithm (GA) with surface
meshing code for the analysis of a 2×2 antenna arrays on EBG was developed. Here the
impedance matrix resulting from the meshing analysis is manipulated by the GA
process in order to find the optimal antenna and EBG operated at 2.4 GHz with the goal
of targeting a specific fitness function. Furthermore, an investigation of GA on 2×2
printed slot on DGS was also done. / Ministry of Higher Education Malaysia and Universiti Tun Hussein Onn Malaysia (UTHM)
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/5385 |
| Date | January 2011 |
| Creators | Abidin, Z.Z. |
| Contributors | Abd-Alhameed, Raed, McEwan, Neil J. |
| Publisher | University of Bradford, School of Engineering, Design and Technology |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Thesis, doctoral, PhD |
| Rights | <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-nd/3.0/88x31.png" /></a><br />The University of Bradford theses are licenced under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-nd/3.0/">Creative Commons Licence</a>. |
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