Study And Implementation Of Three-Dimensional Diffractive Gaussian Beam Analysis Method On DGBA

Quasi-optical technique is a challenging field relating to both microwave technology and optical technology.Nowadays the quasi-optical system has been gradually used to the field of space exploration、radio astronomy、 meteorological satellite and the interstellar peer applications.This topic mainly studies the design verification of the three dimension algorithm in the application of optical network system.This thesis completes the three-dimensional numerical quasi-optical system research and implementation of the algorithm based on the analysis of diffraction of gaussian beam method.The author first describes the characteristics of Gaussian optics and introduces the gaussian beam propagation、transformation of gaussian beam and pattern matching, which is the basis of the theory of quasi-optical system.There are many analysis methods for quasi optical system as geometrical optics、 physical optics and geometric diffraction analysis method.From the performance of the system accuracy and calculation of the rapid effectiveness of consideration DGBA algorithm is a kind of comprehensive analysis method which calculates reflection electromagnetic component and diffraction electromagnetic component for the analysis of electrically large reflector antennas.This thesis adopts the approach of full plane expansion,where the illuminating field over the whole input plane is decomposed into a set of elementary Gaussian beams.The third chapter mainly introduces the gaussian beam propagation gaussian beam reflection and gaussian beam diffraction.This thesis also presents the study of field representation in the forward-scattering region and in the backward-scattering region and shows the generalization to oblique incidence.To check the accuracy of the asymptotic method, the problem of an incident Gaussian beam upon a Kirchhoff half-screen has been analyzed with the commercial reflector analysis tool GRASP.SiMatrix is a kind of quasi-optical system simulation software based on Diffracted Gaussian Beam Analysis developed by QMUL. GRASP is based on well-established analysis techniques such as Physical optics supplemented with the Physical theory of diffraction, Geometrical optics and Uniform geometrical theory of diffraction.The3-dimensional analysis superposes all reflected and diffracted elementary beams and then is verified against a GRASP Physical Optics of a single-reflector or a multi-reflector antenna system.In order to verity the effectiveness of the proposed algorithm theory, this paper designs a set of3-dimensional quasi-Optical network system. According to the design of system index,parametric study and optimization of the network system, the work of optimization,processing and test has also been conducted.