Periodic structures in waveguides
نویسنده
چکیده
We consider structures of period 2 spanning a two-dimensional waveguide of width 2N . Scattering problems where Neumann conditions are imposed on the boundary of the structure and either Neumann or Dirichlet conditions are applied on the guide walls are decomposed into N +1 independent problems. The existence of at least N trapped modes is proved for the Neumann guide case and for the Dirichlet case we prove that at least N −1 such modes exist, this number increasing to N if a certain geometrical condition is satisfied.
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