Novel Dual-Mode Dual-Band Filters Using Coplanar-Waveguide-Fed Ring Resonators

摘要: This paper presents a novel approach for designing dual-mode dual-band bandpass filters with independently controlled center frequencies and bandwidths. Two microstrip perturbed ring resonators are employed to obtain responses. Novel feeding structures introduced simultaneously feed the conveniently control coupling strength between lines, resulting in wide tunable range of external quality factors. kinds filter configurations compact size proposed. Both them provide sufficient degrees freedom satisfy various requirements qualify factors coefficients at both passbands. Therefore, fractional bandwidths passbands can be tuned desired specifications within range. To verify proposed method, four implemented. The measured results exhibit responses high selectivity.