Ergül, ÖzgürGürel, Levent2016-02-082016-02-0820101070-4698http://hdl.handle.net/11693/22134We present fast and accurate solutions of electromagnetics problems involving realistic metamaterial structures using a lowfrequency multilevel fast multipole algorithm (LF-MLFMA). Accelerating iterative solutions using robust preconditioning techniques may not be sufficient to reduce the overall processing time when the ordinary high-frequency MLFMA is applied to metamaterial problems. The major bottleneck, i.e., the low-frequency breakdown, should be eliminated for efficient solutions. We show that the combination of an LF-MLFMA implementation based on the multipole expansion with the sparse-approximate-inverse preconditioner enables efficient and accurate analysis of realistic metamaterial structures. Using the robust LF-MLFMA implementation, we demonstrate how the transmission properties of metamaterial walls can be enhanced with randomlyoriented unit cells.EnglishAccurate analysisElectromagneticsHigh frequency HFIterative solutionsLow frequencyLow-frequency breakdownMetamaterial structuresMulti-level fast multi-pole algorithmMultipole expansionsPreconditionersPreconditioning techniquesProcessing timeTransmission propertyUnit cellsAlgorithmsWalls (structural partitions)MetamaterialsArticle