Solving Scattering from Conducting Body Coated by Thin-Layer Material by Hybrid Shell Vector Element with Boundary Integral Method

Hao-Quan Hu,Jun Hu,Lin Lei

doi:10.1155/2012/854647

Abstract

The finite element boundary integral (FEM-BI) method is widely used in the scattering and radiating problems. But for the conducting body coated by thin-layer material, plenty of fine meshes are required to discretize the geometry in the traditional FEM. It requires very expensive storage and CPU time. In this paper, the hybrid shell vector element with the boundary integral method is used to expedite the solution of thin coating problems. The shell vector elements are used to discretize thin-layer material instead of traditional tetrahedral elements. Consequently, the volume integral can be simplified into surface integral. This method reduces the number of unknowns greatly and is also extended into the complicated case of multi-thin-layer coating materials. Several numerical results are presented to prove the accuracy and efficiency of this present method.

Highlights

The electromagnetic analysis of the conducting body coated by thin-layer material has received much attention because these composite dielectric and conductor structures are used in many applications, such as the evaluation of echo from stealth aircraft and microwave integrated circuits design
In the hybrid shell element with BI, the mesh density of 15 elements per wavelength is enough for achieving reasonable accuracy, but in traditional finite element method (FEM), at least 32 elements per wavelength are required in order to mesh this very thin layer successfully
To further investigate the accuracy of the hybrid shell element-BI, Figure 6 shows the bistatic RCS of the conducting sphere coated by thin dielectric material, the geometry is shown in Figure 5, k0a = 6.28, the thickness of the thin layer is a/100, and the relative permittivity is εr = 4, where k0 is the wave number in free space and a is the radius of the conducting sphere

Summary

Introduction

The electromagnetic analysis of the conducting body coated by thin-layer material has received much attention because these composite dielectric and conductor structures are used in many applications, such as the evaluation of echo from stealth aircraft and microwave integrated circuits design. Besides the integral equation methods, the finite element method (FEM) is widely used for analysis of composite conducting body and dielectric because of its powerful ability of modeling complex inhomogeneous materials [15]. Though FEM-BI has a good computational property for composite conducting body and dielectric, it is deficient for the analysis of conductor structures coated by thin-layer material. This is because plenty of fine meshes will be required for modeling thin layers if using traditional elements like tetrahedral elements. We combine the shell vector element method with the boundary integral method in order to achieve faster solution of scattering from conducting body coated by thin-layer material.

Traditional FEM-BI Method

Numerical Results

Conclusions