Parametric assessment of properties of a periodically patterned surface with non-uniform rectangular spiral metallization in the unit cell

We are presenting numerical results of a parametric study of a device composed of a 2D periodically patterned surface positioned at the interface between two dielectric layers in a parallel-plate waveguide (PPW). The square unit cell contains a non-uniform spiral shaped, planar metal motif which is connected to the ground plane by three vias. Because of the presence of large number of capacitances, by the non-uniform width in the arms of the spiral, and of inductances, introduced by the vias, the proposed arrangement presents an unusual large number of Electromagnetic Band-Gaps (EBGs). The presented results related to different values of the dielectric constant, i.e. to the change of the capacitances, and to various positions of the vias, corresponding to the change of the mutual inductive coupling, have been obtained by full-wave electromagnetic simulations. The device is intended for multi-band filtering applications through incorporation in the structure of antenna feeders and for other dispersion engineering applications.