A compact and high performance band-stop filter using open complementary split ring resonator

Sub wavelength resonators are widely used for size miniaturization and performance enhancement of microwave devices. In this paper, a sub wavelength resonator called an open complementary split ring resonator (OCSRR) is used to design a bandstop filter. Two open stubs of length λg/4 and a single OCSRR are employed for the design of bandstop filter. The open stubs are folded in opposite direction to achieve compact structure. The proposed bandstop filter is having a rejection band of 2.25 GHz. When compared to the conventional bandstop filter, the proposed bandstop filter rejection bandwidth is increased by 59.11% and size is reduced by 15%.