COMPACT LPF DESIGN WITH LOW CUTOFF FREQUENCY USING V- SHAPED DGS STRUCTURE

Department Details

Branch: Engineerings
Department: Electrical Engineering (Electronic and communication) Department
Location: C Building

Research Details

Staff Member Name	Eng. Mohammed Mohie El Dain Shahin
Research Name	COMPACT LPF DESIGN WITH LOW CUTOFF FREQUENCY USING V- SHAPED DGS STRUCTURE
Research Description	A class of compact microstrip Low Pass Filter (LPF) with low 3dB cutoff frequency, ultrabroad stopband, and high stopband attenuation characteristics is introduced. It employs both shaped transmission line and Defected Ground Structure (DGS) techniques to achieve the aforementioned characteristics. In this paper, a new V-shaped DGS structure is introduced. The dimensions of the V-shaped DGS control the 3dB cutoff frequency of the filter. On the basis of this study, different low pass filters having 3dB cutoff frequencies ranging from 1.2GHz to 1.688GHz are designed. A comparison with the low pass filter implemented using double U-shaped DGS structure having same substrate area is carried out. The simulations results indicate that the proposed filter exhibits much lower cutoff frequency than the double U-shaped filter while maintain the same compact size. At 1.688 GHz 3dB cutoff frequency, a wide stopband bandwidth with attenuation level more than 20dB from 2.22 GHz to 7.12 GHz is obtained. Moreover, the occupied area is only (20�19) mm2 as the same area of the original U-shaped filter. Good agreement between the measurements and simulation results is observed.