Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Null Synthesis and Implementation of Cylindrical Microstrip Patch Arrays
Thesis (PhD (Electronic Engineering))--University of Pretoria, 2006.
Saved in:
| Other Authors: | |
|---|---|
| Format: | Thesis |
| Published: |
University of Pretoria
2013
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613523624853504 |
|---|---|
| access_status_str | Open Access |
| author2 | Joubert, Johan |
| author_browse | Joubert, Johan |
| author_facet | Joubert, Johan |
| collection | Thesis |
| dc_rights_str_mv | © 2005, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Thesis (PhD (Electronic Engineering))--University of Pretoria, 2006. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/24717 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:37:30.383Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/24717 Null Synthesis and Implementation of Cylindrical Microstrip Patch Arrays Joubert, Johan Odendaal, J.W. (Johann Wilhelm) pniemand@lantic.net Niemand, Philip Synthesis Null Antenna Microstrip Array Cylindrical Orthogonal Projection Coupling UCTD Thesis (PhD (Electronic Engineering))--University of Pretoria, 2006. As the wireless communications networks expand, the number of both unwanted directional interferences and strong nearby sources increase, which degrade system performance. The signal-tointerference ratio (SIR) can be improved by using multiple nulls in the directions of the interferences while maintaining omnidirectional coverage in the direction of the network users. For the communication system considered, the interferences are static and their spatial positions are known. A non-adaptive antenna array is needed to provide spatial filtering in a static wireless environment. Omnidirectional arrays, such as cylindrical arrays, are the most suitable to provide the omnidirectional coverage and are capable of suppressing interferences when nulls are inserted in the radiation pattern. In this thesis, a cylindrical microstrip patch antenna array is investigated as an antenna to provide an omnidirectional radiation pattern with nulls at specified angular locations to suppress interference from directional sources. Three null synthesis methods are described and used to provide the omnidirectional array pattern with nulls using the radiation characteristics of the cylindrical microstrip patch antenna elements. The orthogonal projection method is extended to incorporate the directive radiation patterns of the cylindrical microstrip patch elements. Using this method, an optimal pattern that minimises the squared pattern error with respect to the ideal pattern is obtained. Instead of only minimising the array pattern error, a multi-objective optimisation approach is also followed. The objective weighting method is applied in null pattern synthesis to improve the amplitude pattern characteristics of the cylindrical patch arrays. As a third null synthesis technique, a constraint optimisation method is applied to obtain a constrained pattern with the desired amplitude pattern characteristics. The influence of the array attributes on the characteristics of the amplitude patterns obtained from the null synthesis methods, is also studied. In addition, the implementation of the cylindrical microstrip patch array is investigated. The influence of the mutual coupling on the characteristics of the null patterns of the cylindrical patch arrays is investigated utilising simulations and measurements. A mutual coupling compensation technique is used to provide matched and equal driving impedances for all the patch antenna elements given a required set of excitations. Test cases in which this technique is used, are discussed and the consequent improvements in the bandwidth and reflection coefficient of a linear patch arrays are shown. The characteristics of the resulting null pattern for the cylindrical microstrip patch array is also improved using the compensation technique. Electrical, Electronic and Computer Engineering unrestricted 2013-09-06T18:12:16Z 2005-05-16 2013-09-06T18:12:16Z 2005-03-06 2006-05-16 2005-05-16 Thesis Niemand, P 2005, Null Synthesis and Implementation of Cylindrical Microstrip Patch Arrays, PhD thesis, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/24717 > http://hdl.handle.net/2263/24717 http://upetd.up.ac.za/thesis/available/etd-05162005-105606/ © 2005, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf application/pdf University of Pretoria |
| spellingShingle | Synthesis Null Antenna Microstrip Array Cylindrical Orthogonal Projection Coupling UCTD Null Synthesis and Implementation of Cylindrical Microstrip Patch Arrays |
| title | Null Synthesis and Implementation of Cylindrical Microstrip Patch Arrays |
| title_full | Null Synthesis and Implementation of Cylindrical Microstrip Patch Arrays |
| title_fullStr | Null Synthesis and Implementation of Cylindrical Microstrip Patch Arrays |
| title_full_unstemmed | Null Synthesis and Implementation of Cylindrical Microstrip Patch Arrays |
| title_short | Null Synthesis and Implementation of Cylindrical Microstrip Patch Arrays |
| title_sort | null synthesis and implementation of cylindrical microstrip patch arrays |
| topic | Synthesis Null Antenna Microstrip Array Cylindrical Orthogonal Projection Coupling UCTD |
| url | http://hdl.handle.net/2263/24717 http://upetd.up.ac.za/thesis/available/etd-05162005-105606/ |