A novel compact CPW tunable stop band filter using a new Z-DGS-resonator for microwave applications

The paper presents a novel very compact CPW bandstop filter. The designed structure consists of one unit of new Z-DGS resonator, placed on top layer of ground plane between the input and output this structure, which is excited by 50-ohm coplanar line. The designed filter can be used in X-Band applications as the band stop can be shifted to any other desired frequency by tuning the length of the Z-DGS. The proposed filter topology has as benefits good performances in terms of wide stop-band rejection, low insertion loss, high return loss, simple design and more small size (17.908×10 mm2 ) compared to other previous works those reported in literature. The stop-band width is from 3.96 GHz to 6.21 GHz, exhibits a 22.25-dB rejection bandwidth of 45% with high selectivity characteristic at the center frequency of 5.05 GHz.