Bandwidth Study of the Stacked Mushroom EBG Unit Cells

The stacked mushroom-shaped (SMS) electromagnetic bandgap (EBG) unit cell and its design procedure are presented. The cell structure is suggested to reduce the cell size and overcome the problems of manufacturing mushroom-shaped EBG cells over a thick dielectric substrate for low-frequency and wideband applications. A comparison between the SMS cell and the conventional mushroom-shaped cell is introduced based on the achievable frequency bandgap. Moreover, a parametric study is performed to highlight both the electrical and mechanical advantages of the SMS EBG structure. Finally, a prototype of a packaged microstrip line is built to verify the characteristics learned from the numerical analysis.