Novel Tunable Bandstop Resonators in SIW Technology and Their Application to a Dual-Bandstop Filter with One Tunable Stopband

Two novel tunable bandstop resonators in substrate integrated waveguide (SIW) technology are presented: a ridged SIW resonator and an open-ended coplanar waveguide (CPW) resonator that is etched into the SIW's top metallization. The ridged SIW resonator shows a tuning range of 200 MHz at 5.54 GHz. The CPW resonator has a tuning range of 600 MHz at 3.8 GHz. The two bandstop resonators are combined to design a dual-band bandstop filter with one tunable stopband. Measured results confirm that the tunable bandstop circuits presented in this letter can be effectively used in reconfigurable SIW systems.