Higher Order Hybrid FEM-MoM Technique for Analysis of Antennas and Scatterers

• Published in: IEEE transactions on antennas and propagation 2009-05, Vol.57 (5), p.1452-1460
• Main Authors: Ilic, M.M., Djordjevic, M., Ilic, A.Z., Notaros, B.M.
• Format: Article
• Language: English
• Subjects: Antennas; Applied classical electromagnetism; Applied sciences; Approximation; Computational electromagnetics; Curved; curved parametric elements; Diffraction, scattering, reflection; Dimensional analysis; Electromagnetic analysis; Electromagnetic scattering; Electromagnetic wave propagation, radiowave propagation; Electromagnetism; electron and ion optics; Exact sciences and technology; Finite element analysis; Finite element method; finite element method (FEM); Finite element methods; Frequency domain analysis; Fundamental areas of phenomenology (including applications); Galerkin methods; Geometry; higher order modeling; hybrid methods; Mathematical analysis; Mathematical models; method of moments (MoM); Moment methods; numerical techniques; Physics; polynomial basis functions; Polynomials; Radiocommunications; Radiowave propagation; scattering; Solid modeling; Studies; Telecommunications; Telecommunications and information theory; Testing; Versatility
• ISSN: 0018-926X; 1558-2221
• DOI: 10.1109/TAP.2009.2016725

A novel higher order large-domain hybrid computational electromagnetic technique based on the finite element method (FEM) and method of moments (MoM) is proposed for three-dimensional analysis of antennas and scatterers in the frequency domain. The geometry of the structure is modeled using generalized curved parametric hexahedral and quadrilateral elements of arbitrary geometrical orders. The fields and currents on elements are modeled using curl- and divergence-conforming hierarchical polynomial vector basis functions of arbitrary approximation orders, and the Galerkin method is used for testing. The elements can be as large as about two wavelengths in each dimension. As multiple MoM objects are possible in a global exterior region, the MoM part provides much greater modeling versatility and potential for applications, especially in antenna problems, than just as a boundary-integral closure to the FEM part. The examples demonstrate excellent accuracy, convergence, efficiency, and versatility of the new FEM-MoM technique, and very effective large-domain meshes that consist of a very small number of large flat and curved FEM and MoM elements, with p -refined field and current distributions of high approximation orders. The reduction in the number of unknowns is by two orders of magnitude when compared to available data for low-order FEM-MoM modeling.