Study On Simulation Algorithms For Wideband Electromagnetic Characterisitcs Of Composite Objects With Periodic Structures

The Large-scale antenna and periodic structures have been widely used in national defense and civil applications.Numerical methods for antennas and periodic structures have been studied by the researchers throughout the world.Composite targets with periodic structures has very important applications in the field of antennas.When the target is electrically large,the computational efficiency will be greatly reduced.In this thesis,electromagnetic scatterings algorithm of the composite objects with periodic structures is studied.Main contents are as follows.Firstly,the research background and the meaning of the topic is introduced.Numerical methods in computational electromagnetics,especially the integral equation and the method of moments(Mo M),are introduced.Secondly,the equivalent dipole-aggregate basis function method is presented to efficiently analyze electromagnetic scattering by the composite objects with periodic structures.By using the equivalent dipole method,the double integrals that are very time consuming can be avoided,by which the fill-in time of the impedance matrix is reduced.The periodicity of the objects is also considered,which further reduced generation time of the impedance matrix.Simulation results show that this method greatly improves the calculation speed.Meanwhile,the accuracy of the proposed technique is good.Finally,the aforementioned method is combined with the interpolation technique to efficiently compute the wideband electromagnetic scattering by the composite objects with periodic structures.The efficiency is improved by using the proposed method.