A design of low-pass filter by utilizing the defected-ground-structure resonator

In this paper, a new low-pass filter (LPF) using defected ground structure (DGS) with wide rejection bandwidth has been presented in this work. Compared to the conventional DGS filter with cascade form, the proposed LPF is more compact in the same operated frequency. To provide a good band-stop characteristic, the modified horn-shaped slot and a pair of the modified arc-head slots are embedded inside the resonator cell. Moreover, adding a parasitically circular patch at the microstrip line reduces the operated frequency and enhances the rejection bandwidth. The proposed LPF has been fabricated, and measured results are also shown in this paper.