MLFMA solutions of transmission problems Involving realistic metamaterial walls

Ergül, Özgür Salih
Gürel, Levent
We present the solution of multilayer metamaterial (MM) structures containing large numbers of unit cells, such as split-ring resonators. Integral-equation formulations of scattering problems are solved iteratively by employing a parallel implementation of the multilevel fast multipole algorithm. Due to ill-conditioned nature of the problems, advanced preconditioning techniques are used to obtain rapid convergence in the iterative solutions. By constructing a sophisticated simulation environment, we accurately and efficiently investigate large and complicated MM structures.
2007 Computational Electromagnetics Workshop


Guerel, L.; Ergül, Özgür Salih; Uenal, A.; Malas, T. (2009-01-01)
We report fast and accurate simulations of metamaterial structures constructed with large numbers of unit cells containing split-ring resonators and thin wires. Scattering problems involving various metamaterial walls are formulated rigorously using the electric-field integral equation, discretized with the Rao-Wilton-Glisson basis functions. Resulting dense matrix equations are solved iteratively,where the matrix-vector multiplications are performed efficiently with the multilevel fast multipole algorithm....
Analysis of Composite Structures Involving Near-Zero-Index Materials
Koyaz, Yesim; İbili, Hande; Karaosmanoglu, Bariscan; Ergül, Özgür Salih (2019-01-01)
We consider numerical solutions of electromagnetic problems involving near-zero-index materials with permittivity and/or permeability values close to zero. These types of problems are inherently multiscale due to the large variety of the wavelength from very large values to ordinary values in the same problem. In addition to developing a stable formulation for extreme values of the intrinsic impedance, we employ a broadband multilevel fast multipole algorithm based on approximate diagonalization for efficie...
Computational analysis of complicated metamaterial structures using MLFMA and nested preconditioners
Ergül, Özgür Salih; Yavuz, Ç.; Ünal, A.; Gürel, L. (2007-11-16)
We consider accurate solution of scattering problems involving complicated metamaterial (MM) structures consisting of thin wires and split-ring resonators. The scattering problems are formulated by the electric-field integral equation (EFIE) discretized with the Rao-WiltonGlisson basis functions defined on planar triangles. The resulting dense matrix equations are solved iteratively, where the matrix-vector multiplications that are required by the iterative solvers are accelerated with the multilevel fast m...
Novel SIE formulations for accurate and stable analysis of near-zero-index materials
KARAOSMANOGLU, BARISCAN; OZMU, UTKU; Ergül, Özgür Salih (2019-07-01)
© 2019 IEEE.We present surface-integral-equation formulations for accurate and stable solutions of electromagnetic problems involving near-zero-index materials with arbitrarily small permittivity and/or permeability values. The formulations are developed for conventional discretizations, while they can be implemented by using interaction routines of existing solvers. Initial results on canonical objects clearly demonstrate the superiority of the developed formulations in comparison to the conventional ones.
Hybridizing physical optics with MLFMA for efficient scattering computations of three-dimensional complex targets
Manyas, Alp; Ergül, Özgür Salih; Gürel, Levent (2009-07-23)
The multilevel fast multipole algorithm (MLFMA) provides accurate and efficient solutions of electromagnetic scattering problems involving large and complicated structures. On the other hand, whenever applicable, accelerations provided by approximation techniques can be useful to further improve the efficiency of solutions. In this paper, we present a hybrid technique, which combines the physical-optics (PO) method and MLFMA for efficient scattering computations of three-dimensional objects. We show that, w...
Citation Formats
Ö. S. Ergül and L. Gürel, “MLFMA solutions of transmission problems Involving realistic metamaterial walls,” presented at the 2007 Computational Electromagnetics Workshop, İzmir, Turkey, 2007, Accessed: 00, 2020. [Online]. Available: