Abstract:
Electromagnetic bandgap (EBG) or alternatively called photonic band gap (PBG) structures have been attractive to obtain the function of unwanted frequency rejection and circuit size reduction. Researches on the PBG had been originally carried out in the optical frequency. Recently, there has been an increasing interest in microwave and millimeter wave applications of PBG circuits. This paper presents a tutorial overview of the new approach for designing compact filters like low pass, band stop and band pass having several advantages than Photonic Band Gap (PBG). This technique is termed as Defected Ground Structure (DGS). The basic conceptions and transmission characteristics with equivalent circuit models of varieties of DGS units are presented. Lastly, the main applications of DGS in microwave technology field have been described.

Keywords: EBG, PBG, DGS