A microstrip dualband bandstop filter with dualband bandstop resonators

A novel compact microstrip dualband bandstop filter with dualband bandstop resonator is proposed in this paper. The dualband bandstop resonator consists of a main line and five-order dualband bandstop resonators. The equivalent circuit model of the dualband bandstop resonator is extracted and the effects of the different design parameters on the performance of the dualband Bandstop resonator are investigated. A dualband Bandstop filter with frequencies at 5.6 GHz and 6.2 GHz is designed, simulated and fabricated to verify the proposed design method. Simulation and measurement show this filter generates two stopbands around 5.54 GHz and 6.26 GHz.