The Dgs Microstrip Filter

Defected Ground Structure (DGS) is a new structure proposed in recent years, which is extended from Photonic Band-Gap (PBG) Structure. DGS can change the effective permittivity of material and distributed capacitor and distributed inductance by etching the periodic or nonperiodic defected pattern on the ground plane of microwave circuit. DGS is widely used in microwave circuit and millimeter circuit. It may improve the performance of microwave integrated circuits (MIC), so it becomes a research hotspot of MIC design domain.Much and deep research on DGS is made in this paper. First, the development and the status quo of DGS are summed up, three types of DGS are summarized with comparisons, and the LC equivalent circuit of DGS is researched and validated with electromagnetic simulations and circuit simulations. Then, the effect of changing several parameters of dumbbell shaped DGS is analyzed and discussed particularly. Based on the study and analysis of dumbbell shaped DGS, a new type of DGS is proposed, and its performance is discussed with electromagnetic simulation. The result of simulation shows that the proposed DGS has smaller dimension compared with traditional dumbbell shaped DGS, and this proves the utility of the proposed DGS. At last, traditional design methods and study hotspots of filters in recent years are discussed, and applying the proposed DGS in design of microstrip filters. The result shows that the performance of filters is improved without increasing the circuit area, and it also proves the utility and practicability of the proposed DGS.