A computational method for modeling arbitrary junctions employing different surface integral equation formulations for three-dimensional scattering and radiation problems

Abstract

This paper presents a new method, based on the well-known method of moments (MoM), for the numerical electromagnetic analysis of scattering and radiation from metallic or dielectric structures, or both structure types in the same simulation, that are in contact with other metallic or dielectric structures. The proposed method for solving the MoM junction problem consists of two separate algorithms, one of which comprises a generalization for bodies in contact of the surface integral equation (SIE) formulations. Unlike some other published SIE generalizations in the field of computational electromagnetics, this generalization does not require duplicating unknowns on the dielectric separation surfaces. Additionally, this generalization is applicable to any ordinary single-scatterer SIE formulations employed as baseline. The other algorithm deals with enforcing boundary conditions and Kirchhoff's Law, relating the surface current flow across a junction edge. Two important features inherent to this latter algorithm consist of a mathematically compact description in matrix form, and, importantly from a software engineering point of view, an easy implementation in existing MoM codes which makes the debugging process more comprehensible. A practical example involving a real grounded monopole antenna for airplane-satellite communication is analyzed for validation purposes by comparing with precise measurements covering different electrical sizes.

Junction modeling for piecewise non-homogeneous geometries involving arbitrary materials

“…In this work, five different SIE formulations, which are all described for isolated bodies in [7], have been used. A generalization for problems involving multiple bodies is in preparation [8]. These five formulations are known in the literature as PMCHWT, CTF, CNF, MNMF (modified MUlier) and JMCFIE [7].…”

Large Complex Impedance and Dielectric Inhomogeneous Structure Scattering Analysis Based on Multi-Level Fast Multipole Method and Iterative Physical Optics

“…하지만, 하 나의 edge에 서로 다른 매질의 메쉬가 존재하는 경우인 junction edge에서 다중 복합 매질 구조의 산란 문제를 다 루는 것은 여전히 많은 연구가 진행되고 있지만 [8] , 서로 다른 매질 간의 내/외부 전류에 의한 경계 조건뿐만 아니 라, junction edge에서 전류의 흐름과 관련된 키르히호프 의 법칙(Kirchhoff's Law)도 고려되어야 하는 문제점이 있 다 [9] . PEC(perfect electric conductor)와 유전체가 존재하는 물체의 전자기 산란 해석을 위해 EFIE(electric field integral equation)-CFIE(combined field integral equation)에 가상의 RWG(Rao-Wilton-Glisson) 기저 함수를 할당하거 나 [2], [10] junction 영역에 가상의 메쉬 세트(mesh set) [11] 를 이용한 방법이 제안되었지만, 이 경우 기존의 표면 적분 방정식의 복잡도가 증가하며, 메쉬 세트로 인해 미지수의 개수가 증가하여 메모리와 시뮬레이션 시간이 증가한다.…”