2017/07/16 by Oscar P. Bruno, Bruno, Oscar, Martín Maas +1
Physics and Astronomy · Engineering · Materials Science · #Electromagnetic Scattering and Analysis #Advanced Antenna and Metasurface Technologies #Metamaterials and Metasurfaces Applications
paper · pdf · doi:10.48550/arxiv.1707.04950
This paper introduces a fast algorithm, applicable throughout the\nelectromagnetic spectrum, for the numerical solution of problems of scattering\nby periodic surfaces in two-dimensional space. The proposed algorithm remains\nhighly accurate and efficient for challenging configurations including randomly\nrough surfaces, deep corrugations, large periods, near grazing incidences, and,\nimportantly, Wood-anomaly resonant frequencies. The proposed approach is based\non use of certain `shifted equivalent sources' which enable FFT acceleration of\na Wood-anomaly-capable quasi-periodic Green function introduced recently (Bruno\nand Delourme, Jour. Computat. Phys., 262--290, 2014). The Green-function\nstrategy additionally incorporates an exponentially convergent shifted version\nof the classical spectral series for the Green function. While the\ncomputing-cost asymptotics depend on the asymptotic configuration assumed, the\ncomputing costs rise at most linearly with the size of the problem for a number\nof important rough-surface cases we consider. In practice, single-core runs in\ncomputing times ranging from a fraction of a second to a few seconds suffice\nfor the proposed algorithm to produce highly-accurate solutions in some of the\nmost challenging contexts arising in applications.\n