Research And Application Of The Time Domain Fast Dipole Method

Time domain integral equation method has outstanding advantages in the analysis of the wide band electromagnetic problem and transient electromagnetic problem. With the increasing demand for military and civilian need such as electromagnetic compatibility, anti stealth technology, antenna radiation and transient signal analysis, the research on the time domain integration equation method is becoming more and more urgent and necessary. However, when analyzing electromagnetic characteristics of electrically large complex structure of target, the growing inefficiency has emerged in the time domain integral method. So how to quickly solve the impedance matrix equation and minimize the computation time and memory consumption is a hot research topic in the time domain integral method. In this paper, the time domain fast dipole method is introduced to alleviate the problems mentioned above.The first part of this thesis introduces the research background and significance of this study. In the second part, the basic theory of the marching-on-in-time(MOT)-based time domain integral equation(TDIE) algorithm is introduced. According to the Maxwell equation and boundary conditions, the surface integral equations and the volume integral equations are established. The discrete matrix equations are obtained by expanding and testing the equations with time base functions and spatial basis functions. Then the discrete matrix equations can be solved iteratively using the standard MOT scheme.The third part of the paper mainly introduces the time domain fast dipole method(TD-FDM) to accelerate the solution of the time domain volume and surface integral equation(TD-VSIE). When the volume and surface integral equation was used to analyze the composite metal and dielectric objects, huge memory requirement and computation time makes it difficult to analyze the electrically large objects. So we introduce the TD-FDM, which can reduce the computation time and the memory consumption of the TD-VSIE, so that it can be used to analyze the electrically large targets.The fourth part of this thesis mainly describes the TD-FDM to accelerate the time domain discontinuous galerkin method(TDDG). The TDDG method presents a very appealing possibility on non-conformal discretizations, which can effectively analyze the electromagnetic characteristics of the targets with complex shape. However, this method has the disadvantage of low computational efficiency inherent in the traditional TDIE method. The TD-FDM is used to accelerate the TDDG method. It can not only take advantage of non conformal discretization of the TDDG method, but also can take advantage of efficiency of the fast algorithm, so it provides an effective method for the analysis of electromagnetic characteristics of electrically large complex objects.