Higher Order Large-Domain FEM Modeling of 3-D Multiport Waveguide Structures With Arbitrary Discontinuities

Efficient Time-Domain Analysis of Waveguide Discontinuities Using Higher Order Fem in Frequency Domain

“…However, it has frequently been found to be impractical and computationally costly in traditional small-domain FEM models, due to the fact that placing the ports far from discontinuities (needed to ensure a single-mode simulation) requires a considerable number of additional elements to be employed, which significantly enlarges the computational domain and introduces a large number of new unknowns to be determined. On the other side, this major drawback can be very effectively overcome in the higher order large-domain waveguide modeling, by placing a single large element with a high field-approximation order in the longitudinal direction as a buffer zone between each port and the domain with discontinuities [2]. The sufficient length of the buffer-element allows for the higher modes excited at the discontinuity to relax before they reach the port, while the high-order field expansion in the longitudinal direction ensures the accurate approximation of the fields throughout the element, without introducing an unnecessarily large number of new unknowns.…”

“…There is a growing need for electromagnetic modeling and analysis of modern waveguide-based microwave devices, to predict their performance and/or optimize various design parameters prior to costly prototype development [1][2][3][4][5][6]. The finite element method (FEM), as one of the most powerful and versatile general numerical tools for electromagnetic-field computations [7][8][9][10], has been especially effectively used in full-wave three-dimensional (3-D) frequency-domain simulations of a broad range of multiport waveguide structures with arbitrary metallic and dielectric discontinuities, and the FEM is well established as a method of choice for such applications [1,2].…”

“…The finite element method (FEM), as one of the most powerful and versatile general numerical tools for electromagnetic-field computations [7][8][9][10], has been especially effectively used in full-wave three-dimensional (3-D) frequency-domain simulations of a broad range of multiport waveguide structures with arbitrary metallic and dielectric discontinuities, and the FEM is well established as a method of choice for such applications [1,2]. However, timedomain analysis and characterization of such structures and evaluation of associated transient electromagnetic phenomena are also of great practical importance for a number of well-established and emerging areas of applied electromagnetics, including wideband communication, electromagnetic compatibility, electromagnetic interference, packaging, high-speed microwave electronics, signal integrity, material characterization, and other applications [11][12][13].…”

“…This paper demonstrates exactly opposite -that with a highly efficient and appropriately designed frequency-domain FEM technique it is possible to obtain extremely fast and accurate time-domain solutions of microwave passive structures performing computations in the frequency domain along with the DFT/IDFT. The technique is a higher order large-domain Galerkin-type FEM for 3-D analysis of N -port waveguide structures with arbitrary metallic and dielectric discontinuities implementing curl-conforming hierarchical polynomial vector basis functions of arbitrarily high field-approximation orders in conjunction with Lagrange-type curved hexahedral finite elements of arbitrary geometrical orders [2], coupled with standard DFT and IDFT algorithms. The technique allows electrically large elements that are up to about two wavelengths in each dimension (large domains), thus fully exploiting the accuracy, efficiency, and convergence properties of the higher order FEM.…”

Comparison of higher order fem and MOM/SIE approaches in analyses of closed- and open-region electromagnetic problems

“…H IGHER ORDER full-wave three-dimensional (3-D) large-domain techniques in computational electromagnetics (CEM) have proven themselves to be flexible and efficient in modeling of complex structures [1][2][3][4][5][6]. The reduction in computation costs is by up to one to two orders of magnitude when compared to low order (small-domain) techniques, for the same or better accuracy.…”