High-Q defected ground structure having spurious free wide passband

A novel defected ground structure (DGS) for microstrip is presented in this paper. This novel DGS has high Q-factor required to suppress the unwanted signal, which is closely located near the desired signal in the spectrum. Also, this DGS resonator exhibits the spurious free wide passband. Acomparative study of the properties of different DGS resonators is also presented. A more accurate modeling of this novel proposed DGS resonator is presented in order to incorporate the higherorder modes. The equivalent circuit consists of a series as well as parallel resonances of this resonator. As the application of this resonator, a bandstop filter is designed, fabricated and measured. © 2012 ISRAMT.