A Fast, Hybrid, Time-Domain Discontinuous Galerkin-Physical Optics Method for Composite Electromagnetic Scattering Analysis

Ceyi Ma,Yinghong Wen,Jinbao Zhang

doi:10.3390/app11062694

Abstract

To accelerate the solution of transient electromagnetic scattering from composite scatters, a novel hybrid discontinuous Galerkin time domain (DGTD) and time-domain physical optics (TDPO) method is proposed. The DGTD method is used to solve the accurate scattering field of the multi-scale objects region, and a hybrid explicit-implicit time integration method is also used to improve the efficiency of multi-scale problems in the time domain. Meanwhile, the TDPO method is used to accelerate the speed of surface current integration in an electrically large region. In addition, the DGTDPO method considers the mutual coupling between two regions, and effectively reduces the number of numerical calculations for the other space of the composite target, thereby significantly reducing the computer memory consumption. Numerical results certified the high efficiency and accuracy of the hybrid DGTDPO. According to the results, in comparison with the DGTD algorithm in the entire computational domain, the DGTDPO method can reduce computing time and memory by 90% and 70% respectively. Meanwhile, the normalized root mean square deviation (NRMSD) of the time-domain, high-frequency approximation method is over 0.2, and that of the DGTDPO method is only 0.0971. That is, compared with the approximation methods, the hybrid method improves the accuracy by more than 64%.

Highlights

Published: 17 March 2021Nowadays, analysis of multi-scale composite transient electromagnetic scattering is an essential part of ocean detection [1], the reconstructing of the microwave imaging of objects [2], etc
B, the electric field in the time domain and frequency domain from 0.5 to 1 GHz was calculated by discontinuous Galerkin time domain (DGTD), and the result is almost consistent with that of HFSS; the resulting normalized root mean square deviation (NRMSD) values were 0.0112 and 0.0053 respectively. These results show that DGTD method can be used to calculate the multi-scale problem very well
2021, 11, 2694via the DGTD method, and the NRMSD values were 0.0328 and 0.0619 respec- 13 of 16 calculated tively. These results demonstrate that DGTD method can be used to calculate the multi-object problem

Summary

Introduction

Published: 17 March 2021Nowadays, analysis of multi-scale composite transient electromagnetic scattering is an essential part of ocean detection [1], the reconstructing of the microwave imaging of objects [2], etc. A large-scale environment, such as a rough sea or land surface, will lead to a sharp increase in computing memory and time, and computers cannot keep up. These problems bring challenges to computational electromagnetism. In order to take into account both accuracy and efficiency, the main method is to mix the full wave method with the high frequency approximation algorithm In these methods, the full-wave methods, such as the method of moments (MoM), the finite-element time domain (FETD), finite volume time domain (FVTD) and finite-difference time domain (FDTD) calculate the regions with fine structures well. Due to the good accuracy of MoM, a class of hybrid methods of MoM and high-frequency approximation algorithms are widely used [3,4,5,6,7,8]

Methods

Results

Conclusion