Time - Domain Analysis Of Electromagnetic Scattering Characteristics Of Rotating Symmetries In Non - Homogeneous Media

The method of moment is effectively used for solving electromagnetic scattering and radiation problems. In order to take advantage of the rotational property of the object in space, the patch of the inhomogeneous dielectric body of revolution(BOR) just be meshed using Fourier Series.Thus, the unkowns of azimuthal field can be reduced largely.In this dissertation, the time domain integral equation based on marching-on-in-degree method has been used for solving inhomogeneous dielectric bodies of revolution and coated objects problems. The weighted Laguerre polynomials are used in the method based on marching-on-in-degree. And the expressions of three different basic functions are defined in zero mode and non-zero mode. After then a marching-on-in-degree method has been used to analyze the scattering property of the bodies of revolution, including dielectric objects, inhomogeneous dielectric objects and coated objects.Firstly, the time-domain volume integral equation based on the body of revolution (BOR-MOD-VIE) is proposed to analyze the dielectric objects and inhomogeneous dielectric objects. Secondly, the adaptive cross approximation (ACA) algorithm has been used for compressing impedance matrix, saving computer memory resources and improving computational efficiency. Thirdly, the time-domain volume and surface integral equation based on the body of revolution (BOR-MOD-VSIE) is proposed to analyze coated objects Compared to the time-domain volume integral equation(TD-VIE) and volume and surface integral equation(TD-VSIE), there are less unknowns in the method which can save time and memory consumption.Finally, a marching-on-in-degree procedure based time domain integral equation method(BOR-MOD-TDS) is proposed to analyze the electromagnetic scattering of conductor-backed thin materials, one need just to mesh along a longitudinal of the structure instead of the whole object due to taking advantage of the rotational property of the object. According the perfect conductor boundary conditions and the relations of current and charge, all the sources of dielectric section can be converted into the surface induced current on the conductor surfaces, so there is only one unknown in the time-domain integral equation.