Rotationally Symmetric Electromagnetic Scattering Finite Element Method

The electromagnetic scattering of 3D targets has attracted much more attention in computational electromagnetic (EM) research. The method of finite-element method (FEM) is often effectively used for solving electromagnetic scattering problems. By use of the FEM and rotational symmetry the paper has studied the scattering from bodies of revolution, and the results are expressed in terms of generalized radar cross section.At the beginning of this paper, we briefly discussed and investigated the basic theory, current development status of the finite element method. Then an efficient finite-element method (FEM) is developed to compute scattering from a complex body of revolution (BOR). The BOR is composed of perfect conductor and impedance surfaces and arbitrary inhomogeneous materials. The method uses edge-based vector basis functions to expand the transverse field components and node-based scalar basis functions to expand the angular component. The use of vector basis functions eliminates the problem of spurious solutions suffered by other three component FEM formulations. The FEM mesh is truncated with a perfectly matched layer (PML) in cylindrical coordinates. The use of PML in cylindrical coordinates avoids the wasted computation which results from a spherical mesh boundary with an elongated scatter. The method is capable of handling large, realistic radar targets, and good agreement with measured results is achieved for benchmark targets.