Microstrip bandstop filter using open stub and spurline

Microstrip filters are widely used in microwave circuit, This paper briefly describes the design principle of microstrip bandstop filter(BSF). A compact wide band high rejection BSF is presented. This filter combines two traditional BSFs: open stub filter and spurline filter. Due to the inherently compact characteristics of the spurline, the proposed filter shows a better rejection performance than open stub BSF without increasing the circuit size. The results of simulation and optimization given by CST2010 prove the correctness of the design.