Uwb Filter Using Defected Ground Structure Of Von Koch Fractal Shape Slot

A coupled defected ground structure (CDGS) is presented which is synthesized by etching Von Koch fractal shape slot in the ground plane and series capacitive gap in the conductor strip. Unlike the structures loaded with complementary split ring resonators (CSRRs), the proposed structure can operate at very wide band. A UWB filter using the above structure is fabricated and tested. The relative bandwidth of the -10 dB return loss is 128% and the insertion loss is better than 1.5 dB except at high frequencies. The equivalent circuit model of the proposed structure is presented and the electrical parameters are also extracted. The circuit model results are compared with the simulated and measured results which verify that the equivalent circuit model is reasonable.