پديد آورنده :
احمدي ونهري، ريحانه
عنوان :
محاسبه سطح مقطع راداري اجسام با معادلات انتگرالي تزويج شده و مقايسه با تحليل مدهاي مشخصه
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
مخابرات ميدان و موج
محل تحصيل :
اصفهان : دانشگاه صنعتي اصفهان
صفحه شمار :
دوازده، 85ص. : مصور، جدول، نمودار
استاد راهنما :
احمد بخت افروز
استاد مشاور :
محسن مداح علي
توصيفگر ها :
معادلات انتگرالي تزويج شده , روش ممان , سطح مقطع راداري , تئوري مدهاي مشخصه
استاد داور :
ابوالقاسم زيدآبادي نژاد، ذاكر حسين فيروزه
تاريخ ورود اطلاعات :
1398/08/01
دانشكده :
مهندسي برق و كامپيوتر
تاريخ ويرايش اطلاعات :
1398/08/01
چكيده انگليسي :
RCS Calculation of Objects Using Coupled Integral Equations and Comparison with Characteristic Modes Analysis Reihaneh Ahmadi Vanhari reihaneh ahmadi@ec iut ac ir September 22 2019 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisor Assist Prof Ahmad Bakhtafrouz bakhtafrouz@cc iut ac ir Abstract Nowadays numerical methods are widely used as precise methods in electromagnetic problemsanalysis at different frequency ranges different system sizes and for such a broad spectrum of ap plication areas as design of antennas and microwave devices and circuits electromagnetic scatter ing communication systems etc Numerical computational electromagnetic CEM techniques canbroadly be classified into those based on integral equation formulations IE differential equationformulations DE and hybrid techniques combining the IE and DE approaches As the general nu merical discretization procedures for transforming the integral and differential equations into a matrixequation the CEM uses the method of moments MOM to discrete IE and both finite element method FEM and finite difference time domain FDTD method to discrete DE Integral equations in mate rial bodies are as a set of coupled integrals in terms of electric and magnetic currents on their surfaces In analysis of composite structures PEC and dielectric based on surface integral equations the effectof each surface current is considered on the other surfaces and therefore coupled integral equationsare created The importance of these composite structures especially dielectric coated bodies is in thedesign of stealth aircraft and missiles which have been coated with absorbing layers and cloaks Afterdiscretization of integral equations an eigenvalue eigenvector equation is defined based on charac teristic modes CM analysis Solving this problem results in characteristic currents and fields ofthe structure which define natural features of system Then total current and field can be expandedas a linear combination of characteristic modes CM analysis is widely used in antenna and scat tering problems With this method basic antenna parameters e g efficiency gain bandwidth andpolarization can be improved significantly Moreover using entire domain basis functions which areobtained with the expiation of characteristic currents in multiple scattering problems significantlyreduces the number of unknowns Another important application of CM in scattering problems isthe design of electromagnetic cloaks and absorbers Stealth objects usually have been made of con ductor with dielectric coating In this thesis at first integral equations related to PEC and dielectricobjects are formulated separately and implemented numerically Then coupled integral equations incomposite structure are evaluated These equations are discretized with MOM and after obtainingcurrents in the structure its radar cross section is calculated At the end with the use of CM andsolving eigenvalue eigenvector equation characteristic currents are calculated and the entire domainradar cross section is obtained accordingly Key Words Coupled Integral Equations Method of Moments Radar Cross Section CharacteristicModes Theory
استاد راهنما :
احمد بخت افروز
استاد مشاور :
محسن مداح علي
استاد داور :
ابوالقاسم زيدآبادي نژاد، ذاكر حسين فيروزه
