A Fast Algorithm For Transient Electromagnetic Scattering From Metal Targets

Computational electromagnetic is of great significance for electromagnetic engineering. In the field of computational electromagnetic, in order to analyze target electromagnetic characteristics quickly and accurately, many researchers have done lots of works. After years of effort, they propose a variety of classic algorithms which greatly promote the development of electromagnetism. We study the MOT in two aspects on how to quickly analyze target electromagnetic characteristics. The first aspect is space and the second aspect is time. This paper contains two parts:the marching-on-in-time based on higher order hierarchical vector basis function (HOMOT) and the envelope-tracking marching-on-in-time.In this paper, we introduce the basic principle and implementation process of the HOMOT. The construction of higher order hierarchical vector basis function is introduced firstly, and then the application of the basis function in marching-on-in-time based the time domain integral equation is proposed. The HOMOT can effectively reduce the memory and save the time required for analyzing the electromagnetic characteristics. On electrically large targets, the HOMOT still costs a lot of time and memory. The Plane wave time domain (PWTD) and the HOMOT are combined to further save the time and the memory.The HOMOT has achieved the goal of solving electromagnetic characteristics quickly and accurately. The second part of the research studies how to quickly solve target electromagnetic characteristics from the aspects of time. This part mainly introduces the principle of the envelope-tracking marching-on-in-time, and also the concrete implementation process of the envelope-tracking marching-on-in-time. Firstly it introduces the method of how to achieve signal’s complex envelope, we can use this method to construct the envelope-tracking time domain integral equation. The envelope-tracking time domain integral equation can choose larger time step, so it can solve target electromagnetic characteristics quickly. On this basis of the envelope-tracking marching-on-in-time, we combine the envelope-tracking marching-on-in-time with the Adaptive Cross Approximation (ACA) to further save running time.