Analysis of the scattering fields from pec curved surfaces with modified theory of physical optics


Thesis Type: Postgraduate

Institution Of The Thesis: Bursa Uludağ University, FEN BİLİMLERİ ENSTİTÜSÜ, Turkey

Approval Date: 2015

Thesis Language: Turkish

Student: Mücahit Sarnık

Supervisor: UĞUR YALÇIN

Abstract:

In this master thesis, the fields scattering of the fields, that radiate from a line source, from perfectly conducting cylindrical and parabolic surfaces are analysed. In order to calculate the scattered fields, the reflected and edge-diffracted fields are implemented. The methods which have been developped for scattering problems and used in literature have been explained. It has been detected that these methods have a failure to solve some problems. The Modified Theory of Physical Optic (MTPO), by which those deficiencies are have been solved and which has been recently developped, has been used in this master thesis in order to analyse scatterring fields from curved surfaces. Firstly this theory has been introduced with the related axioms and the differences with respect to Physical Optics (PO). Secondly, MTPO is used to calculate the scatered fields from a perfectly conducting cylindrical reflector. The scattering field integral of MTPO is obtained in terms of the multiplication of magnitude and phase function and the reflecting field at the stationary phase point is calculated. In order to find the edge diffraction, edge-point technique is used and it has been observed that diffraction value diverges to infinity for certain points. Hence, detour parameter ise used to convert the non-uniform values to uniform ones. Thirdly, the scattering fields from a perfectly conducting parabolic reflector is calculated by MTPO. The scattering field integral of MTPO is obtained for parabolic reflector. The obtained expression is converted to a form of magnitude and phase functions and the reflected field is found at the stationary point. The edge-point technique is used to calculate the diffracted field value. Diffracted field has some singular points where the diffraction value diverges to infinity. Detour parameter is applied similar to the problem in the second part. Lastly, the scattered fields are numerically compared with the values already found by the methods in the literature for various angles and it has been concluded that the found results are coherent each other.