Thesis (PhD) -- Stellenbosch University, 2001. / Some digitised pages may appear illegible due to the condition of the original hard copy. / ENGLISH ABSTRACT: A new technique for the design of multimode devices in overmoded waveguide is presented.
The technique applies the principle of growth-based design and uses a conceptual functional
block representation of the design structure to provide necessary flexibility to the design
algorithms. Two growth based design strategies are proposed and evaluated. The first uses a
generalized synthesis-oriented scanning technique, and the second uses an evolutionary
strategy. The techniques provide reliable solutions to a variety of multimode design problems.
In order to facilitate sufficiently fast numerical analysis, novel enhancements of the mode
matching technique are developed and the use of surrogate models is investigated. In addition,
to allow physical evaluation of the finished devices, original techniques of measuring
multimode devices are formulated and utilised.
Two practical problems are used to evaluate the performance of the design procedures. The
first is the design of overmoded waveguide chokes for microwave heating facilities, and the
second is the design of multimode horns for antenna and spatial power combining
applications. Various examples of each type of problem are presented with measurements of
manufactured solutions. / AFRIKAANSE OPSOMMING: ’n Nuwe tegniek vir die ontwerp van multimodusstelsels binne multimodus golfleier word
voorgestel. Die tegniek maak gebruik van die beginsel van groei-georienteerde ontwerp en
ontgin ’n konsepsuele funksionele module-voorstelling van die ontwerpstruktuur om die
nodige buigsaamheid aan die ontwerpsalgoritmes te verleen. Twee groei-georienteerde
ontwerpstrategiee word aangebied en geevalueer. Die eerste is gebasseer op ’n veralgemeende
sintese-georienteerde skandeertegniek, en die tweede maak gebruik van ’n evolusie-strategie.
Die tegniek verskaf betroubare oplossings vir ’n verskeidenheid van
multimodusontwerpsprobleme.
Ten einde ’n numeriese analise-tegniek daar te stel wat vinnig genoeg is, word oorspronklike
verbeterings van die modal-pas metode ontwikkel en surrogaatmodelle is ook ondersoek.
Verder, vir fisiese evaluasie, word oorspronklike meettegnieke vir multimodusstelsels
geformuleer en gebruik.
Twee praktiese probleme word gebruik om die ontwerpprosedures te evalueer. Die eerste is
die ontwerp van multimodus golfleierdrywingsdempers vir mikrogolfverhitting, en die tweede
is die ontwerp van multimodus horings vir antenna- en ruimtelike drywingskombineerdertoepasings.
Verskeie voorbeelde van elke tipe probleem word gegee met metings van
gei'mplementeerde oplossings.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/52291 |
| Date | 12 1900 |
| Creators | Vale, Christopher A. W. |
| Contributors | Meyer, P., Stellenbosch University. Faculty of Engineering. Dept. of Electrical and Electronic Engineering. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 154 p. : ill. |
| Rights | Stellenbosch University |
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