Dual-band bandpass filter with rectangular dumbbell shaped defected ground structure: article / Nik Aswani Nik Ahmad

In this paper, a design of rectangular dumbbell shaped defected ground structure (DGS) is presented to enhance the response of an existing design of a dual-band bandpass filter topology. The filter design is based on parallel-coupled lines connected to transmission lines forming a single ring that exhibits a dual-band response with high selectivity. The filter comprises of characteristics impedances of the transmission line represented by Zr, even-mode, Zre and odd-mode, Zro. The variety of DGS size and positions measurements are acknowledged and the impacts on the response of the filter are analysed [3]. An execution of a rectangular dumbbell shaped DGS in this topology enhances the response for both groups with centre frequency given at 2 GHz using TRF-45 material. The dimension and position of the dumbbell shape is improved individually, situated of the ground plane. The simulated and measured aftereffects of the DGS insertion are analysed and to validate the concept.