Iterative FEBI-PO Hybrid Method for Analyzing Scattering Problems of Complex Structures Having Junctions With Large-Scale Platform

Yang Liu,Haijing Zhou,Xiaojie Chen,Yuteng Zheng,Yumao Wu

doi:10.1109/access.2019.2954581

Abstract

An iterative hybrid of finite element boundary integral (FEBI) method and physical optics (PO) is presented for scattering problems of complex structures having junctions with electrically large-scale platform. The treatment of basis functions on the junctions between complex structures and platform is discussed in detail. Moreover, the multilevel fast multipole algorithm and the adaptive cross approximation method are employed to accelerate the solution of FEBI and the computation of interaction between FEBI and PO regions, respectively. Compared with FEBI method, the hybrid method can efficiently reduce the number of unknowns and the computational complexity while preserving acceptable accuracy. In addition, the alternative implementation of FEBI and PO can also maintain good independence of the two methods. Some numerical results are discussed to demonstrate the efficiency and accuracy of the approach.

Highlights

The numerical simulation of electromagnetic scattering problems is really important for various engineering designs and applications
finite element method (FEM) is used to deal with the interior region of the artificial boundary containing complex structures or inhomogeneous mediums, while the boundary integral equation method is used to describe the fields in the free space of exterior region
In finite element boundary integral (FEBI) region, the vector basis function Ne assigned to edge e is used by FEM, which corresponds to g2, while the RWG basis function g3 is used in the discretization of boundary integral equations for the exterior of FEBI region

Summary

INTRODUCTION

The numerical simulation of electromagnetic scattering problems is really important for various engineering designs and applications. For solving unbounded problems with FEM, an artificial boundary must be introduced to truncate the infinite region, and an absorbing boundary condition needs to be imposed on the artificial boundary for getting a unique solution, which usually results in a large computational domain and truncation error To overcome this difficulty, the finite element boundary integral (FEBI) [2]–[4] becomes a research hotspot and developed rapidly, which is. We focus on discussing the iterative hybrid FEBI-PO method in analyzing scattering problems of complex structures having junctions with large-scale PEC platform, which can both preserve the efficient simulation of complex structures and handle the electrically large-scale PEC platform simultaneously. It is illuminated that, compared with FEBI method, the iterative method converges very fast, and can efficiently reduce the number of unknowns and the computational complexity while preserving acceptable accuracy for solving the scattering problems of complex structures having junctions with large platform. The ACA is adopted to enhance the computational efficiency for coupled matrix of FEBI and PO regions

PROCEDURE OF THE ITERATIVE FEBI-PO METHOD

BASIS FUNCTIONS ON JUNCTIONS

Findings

CONCLUSION