The proliferation of modern wireless networks increases demand for high capacity and
throughput in order to provide faster, more robust, efficient and broadband services to end users.
Mobile WiMAX and LTE are examples of such networks in which for some cases they have
exposed limited connectivity due to harsh environment. Relay stations are preferred to
overcome problems of weak or no access for such network devices, that are placed in specific
positions to maintain high quality of data transfer at low cost and provide the required
connectivity anywhere anytime. These stations should be equipped with an antenna system
capable of establishing communication between base station (backhaul link) and end users
(access link).
This thesis focuses on the design and development of a new antenna system that is suitable for a
relay-based wireless network. Planar geometries of microstrip patch antennas are utilized. The
antenna system comprises two antenna modules: a new design of a single antenna for access
link and a new design of an antenna array for backhaul link realization. Both antenna
specifications are compatible with the IEEE802.16j protocol standard. Hence, relay station
should be capable of pointing its radiation pattern to the base station antenna, thus to achieve the
desired radiation pattern of the relay station, a new beam-forming module is proposed, designed
and developed to generate the proper radiation pattern. The beam-forming module incorporating
digital phase shifters and attenuator chips is fabricated and tested. The optimization process
using the Least Mean Square (LMS) algorithm is considered in this study to assign the proper
phase and amplitude that is necessary to each radiation element excitation current, to produce
the desired steered radiation pattern.
A comprehensive study on the coupling effects for several relative positions between two new
backhaul and access link antenna elements is performed. Two new antenna configurations for
coupling reduction are tested and the simulated and measured results in terms of antenna
radiation performances were compared and commented.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/5770 |
| Date | January 2012 |
| Creators | Petropoulos, Ioannis |
| Contributors | Abd-Alhameed, Raed, Jones, Steven M.R., Voudouris, Konstantinos N. |
| 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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