A new open stubs structure of Kuroda low-pass filter using DGS

This paper presents a new open stub structure of Kuroda low-pass filter using DGS (Defected Ground Structure). Low-pass filter based on Richard's transformation and Kuroda's identity has sharp slope in transition band and very good characteristic in stop band. But it is hard to fabricate the microstrip line because of high impedance of the open stub. So, this paper proposes a new structure that can realize high open stub impedance line through using DGS that inserts into the ground plane of the open stub. 5-orders low-pass filter with proposed design method has been fabricated, measured and compared with the existing structure. The experimental results show excellent agreements with designed and simulated ones.