Computation of waveguide scattering matrix near thresholds |
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Authors: | M M Kabardov B A Plamenevskii N M Sharkova |
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Institution: | 1. The Bonch-Bruevich Saint Petersburg State University of Telecommunications, St. Petersburg, Russia.kabardov@bk.ru;3. Physical Faculty, Saint Petersburg State University, St. Petersburg, Russia. |
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Abstract: | A waveguide occupies infinite strip with one or several narrows on a two-dimensional (2D) plane and is governed by the Helmholtz equation with Dirichlet boundary condition. On the waveguide continuous spectrum, which coincides with a half-axis, a scattering matrix is defined. At each point of the continuous spectrum this matrix has finite size, which changes at thresholds. The thresholds form a sequence of positive numbers increasing to infinity. Approximate calculation of the scattering matrix in a threshold vicinity requires special treatment. We discuss and compare two methods of numerical approximation to the scattering matrix near a threshold. |
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Keywords: | Helmholtz equation scattering matrix threshold augmented wave space |
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