Reflection Phase and Frequency Bandgap Characteristics of EBG Structures with Anisotropic Periodicity

Abstract

An anisotropic mushroom-like electromagnetic bandgap (EBG) structure is studied. Different to the conventional EBG structures with square unit cell, the presented EBG structures are with anisotropic periodicity. The periodic spacing or the metal patch length is different along the two periodic directions. So the reflection phase and the frequency bandgap will show distinct characteristics compared to the conventional EBG structures. These two features of the anisotropic EBG structures have been calculated numerically using FDTD method. The results show that the frequency of in-phase reflection is dependent on the polarization of incident plane wave, and the frequency bandgap along the two orthogonal directions could be designed to be similar or even overlapped.