Novel Dual Band-Reject Microwave Filter Using C-Shaped Defected Ground Structures

Abstract

Abstract-In this paper, a new compact dual band-reject C-shaped defected ground structure (DGS) for microstrip line is introduced. Using two units of the same shaped DGS with different dimensions, a dual band-stop filter is designed and implemented. Results show that there are two parallel resonance frequencies at 2.468 GHz and 6.629 GHz with a very high Q-factor. The frequency characteristics of the proposed filter could be controlled by adjusting the DGS parameters such as width and length of both C-shaped patterns. Also, the distance between the two DGS structure could be adjusted for the required frequency characteristics. The proposed DGS provides Q-factor of more than 50 with attenuation of at least 20 dB at the resonant frequencies. The new introduced DGS filter is successfully designed and fabricated and the measured results are in a very good agreement with those obtained by numerical investigation.Index Terms-Defected ground structure (DGS), dual bandreject filter, Q factor.