Novel compact dual-and tri-band filters using stepped impedance resonators

We present in this paper a novel approach for dual-and tri-band filters design with independently controlled center frequencies and bandwidths. On the one hand, a stepped impedance resonator (SIR) is designed to operate at the center frequencies of two bands simultaneously (dual-band), on the other hand, two stepped impedance resonators are designed to operate at the center frequencies of three bands simultaneously (tri-band). To verify the proposed approach two filters are designed and analyzed by using Sonnet and HFSS simulators, the obtained results using these two simulators are in very good agreement.