Spectral domain analysis of double sided open periodic structures

An analysis of open periodic stratified media is performed using external excitation of a single unit cell. The poles of the reflection and transmission coefficients are obtained from the scattering of plane waves to extract the eigenmodes and corresponding eigenvalues. Surface wave and complex leaky modes of metamaterial structures are obtained efficiently by this method. To show the accuracy of the method the leaky and surface wave modes of a slab waveguide in free space are computed. Afterwards, the method is generalized to inhomogeneous periodic structures. A periodic arrangement of metallic plates is excited in its surface wave mode and the resulting eigenvalues and the dispersion diagram are computed. A good agreement between the results from different methods is observed.