A compact dual-band bandstop filter having one spurline and two embedded open stubs

A compact dual-band microstrip bandstop filter (BSF) is presented. It combines a conventional open-stub BSF, a spurline, and two embedded open stubs. This BSF is simulated and fabricated. It generates two stopbands around 2.0 GHz and 3.0 GHz without increasing circuit size, compared with the conventional BSF.