Physical optics based methods for scattering analysis

Richardson, Micheal Peter (2018-03)

Thesis (MEng)--Stellenbosch University, 2018.

Thesis

ENGLISH ABSTRACT: The physical optics (PO) approximation is often used in asymptotic, electromagnetic scattering analysis to calculate the induced current on a perfectly conducting surface, represented by a mesh. The multiple reflection physical optics (MRPO) method is the recursive application of the PO approximation. MRPO uses full, inter-segment visibility shadowing. Iterative physical optics is similar, except the shadowing is relaxed. Only half-space visibility is used for shadowing. The performance of these methods is investigated for a variety of test cases. The domain decomposition physical optics (DDPO) method is presented. It decomposes the geometry into two parts, a cavity and external geometry. The two geometries interact through an aperture, using equivalent sources. Thus, the shadowing can be calculated for the individual geometries and not as a whole. The equivalent sources and aperture interactions are validated. The performance of DDPO is investigated for various, simple test cases. All methods and results are presented in a two-dimensional, transverse magnetic context.

AFRIKAANSE OPSOMMING: Die fisiese optika (PO) benadering word dikwels gebruik in asimptotiese, elektromagnetiese verstrooiingsanalise om die geïnduseerde stroom op 'n perfek geleidende oppervlak te bereken, wat deur 'n maas voorgestel word. Die veelvoudige weerkaatsing fisiese optika metode (MRPO) is die rekursiewe toepassing van die PO-benadering. MRPO gebruik volledige, inter-segment sigbaarheidsbepaling. Iteratiewe fisiese optika is soortgelyk, behalwe die sigbaarheidsbepaling is minder streng. Slegs halfspasie-sigbaarheid word gebruik. Die uitvoering van hierdie metodes word ondersoek vir 'n verskeidenheid toetsgevalle. Die domein dekomposisie fisiese optika (DDPO) metode word aangebied. Dit breek die struktuur op in twee dele, 'n holte en eksterne gebied. Die twee dele koppel deur middel van ekwivalente bronne op 'n gepaste stralingsvlak. Die skaduweebepaling hoef slegs vir die afsonderlike dele gedoen te word. Verifikasie van die ekwivalente bronne en stralingsvlak interaksies word gedoen. Die prestasie van DDPO word ondersoek vir verskeie, eenvoudige toetsgevalle. Alle metodes en resultate word in 'n tweedimensionele, transversale magnetiese konteks aangebied.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/103536
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