Comparison between line and surface integral formulations of the hybrid mode‐matching/two‐dimensional finite element method

Abstract

SUMMARYThe hybrid mode-matching/two-dimensional-finite-element (MM/FEM2D) technique has been proposed for the analysis of discontinuities with waveguides of arbitrary cross section; this technique combines the computational efficiency of modal analysis with the versatility and flexibility of the FEM approach.In this paper, we present in detail a surface-integrals and a line-integrals formulation of the hybrid MM/ FEM2D technique, in case the 'Standard Formulation' is used as FEM2D formulation. Such formulations allow computing analytically both the normalization and the coupling integrals. Furthermore, we compare the accuracy obtained by using the line-integrals and the corresponding surface-integrals formulation. To these aims we present several numerical results.

A New Hybrid Method for Analysis of Scattering From Arbitrary Configuration of Cylindrical Objects

“…The aforementioned methods are focused on objects located in free space [14]- [18] or in waveguide junctions [19]- [26]. Here the objects are enclosed in a finite region where the solution is obtained with the use of discrete methods such as finite element method (FEM) [15], [20]- [23], [25], [26] finite-difference time-domain (FDTD) [16]- [18] or frequency-domain (FDFD) [14] methods and method of moments (MoM) [16], [18], [19], [24]. In open problems [14]- [18] the relation between the fields in the inner and outer regions is found by calculating the currents on the interface between the regions.…”

Analysis of Scattering From Arbitrary Configuration of Cylindrical Objects Using Hybrid Finite-Difference Mode-Matching Method

“…In comparison to alternative methods [13][14][15][16][17][18][19][20][21] the presented approach allows one to analyze scattering from arbitrary set of cylindrical objects which can be located both in free space or in waveguide junctions. At first, in our approach each single object is considered separately in its local coordinate system.…”

“…Since, in considered problems objects with arbitrary shape are assumed, the most powerful techniques of analysis are hybrid methods [13][14][15][16][17][18][19][20][21]. In these method the discrete techniques such as finite element method (FEM) [13][14][15], finite-difference time domain method (FDTD) [16][17][18] or frequency domain (FDFD) [19] methods and method of moments (MoM) [18,20,21] are used in limited region surrounding the analyzed structure.…”

“…In these method the discrete techniques such as finite element method (FEM) [13][14][15], finite-difference time domain method (FDTD) [16][17][18] or frequency domain (FDFD) [19] methods and method of moments (MoM) [18,20,21] are used in limited region surrounding the analyzed structure. In the outer region the fields are combined with analytical solution of the problem using e.g., integral equation technique [15,17] for open structures or general scattering matrix (GSM) approach for closed problems [13,20,21].…”