A Novel Approach to Enhance the Bandwidth of Mushroom-like EBG Structures

Mushroom-like electromagnetic band gap (EBG) structures exhibit unique properties that have led to a wide range of applications. But the EBG structures´ forbidden band gaps are narrow for their inherent nature, which restrict them to be used widely. In this paper, a novel approach to enhance the bandwidth of the band gap of mushroom-like EBG structures is proposed. The author will discuss the ways to broaden the bandwidth of the band gap from several aspects, for example by adjusting the parameters in proper way, such as the gaps between adjacent patches, the radii of the related vias. The corresponding gaps concern two orthogonal directions - the X-direction and Y-direction, respectively. A notion of windowing method is used to achieve groups of variable radii of vias, and this new type of mushroom-like EBG structure is approved to have a obviously wider bandwidth comparing to those of conventional (or uniform) one. And also the optimal gaps between the adjacent patches in two orthogonal directions that lead to the widest bandwidth are acquired. At the end of this paper, a novel design of mushroom-like EBG structure, which are integrated with both of these two efficient methods, will be obtained and simulated, which exhibit distinctly wider bandwidth than the conventional one.