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Radiation and scattering from periodic geometries in inhomogeneous media

Wen-Jiunn Tsay, University of Massachusetts Amherst


The first part of this dissertation extends the FDTD technique to 2-D inhomogeneous infinite periodic array or scatterers. The FDTD grid needs only to be applied to a single unit cell of the structure, making the analysis of a large structure much simpler and more computationally efficient than the modeling of the entire structure. By implementing the Floquet boundary condition, the fields across the whole unit cell can be obtained. Because a more general total field approach was successful only at the broadside incidence, a simple scattered field source excitation was used for the oblique incidence in stead. Good agreement was observed when compared with the analytical solution. The second part of this dissertation extends the hybrid moment method technique to the infinite periodic printed dipole array with the presence of the dielectric inhomogeneities. The integral equation was set up using the conventional integral equation of an infinite periodic printed dipole array coupled with the equivalent volume polarization electric currents. The volume pulse basis functions were used to expand the volume polarization electric current. A hybrid moment method solution was obtained through the matrix form of the problem. The infinite periodic printed dipole array with dielectric supports and overlays were studied for the computer code validation. Good agreement was observed between the hybrid MoM solutions and the waveguide simulator experiment results.

Subject Area

Electrical engineering

Recommended Citation

Tsay, Wen-Jiunn, "Radiation and scattering from periodic geometries in inhomogeneous media" (1995). Doctoral Dissertations Available from Proquest. AAI9541161.