Novel dual-mode dual-band filters using coplanar-waveguide-fed ring resonators

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

149 Scopus Citations
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  • Xiu Yin Zhang
  • Quan Xue

Related Research Unit(s)


Original languageEnglish
Pages (from-to)2183-2190
Journal / PublicationIEEE Transactions on Microwave Theory and Techniques
Issue number10
Publication statusPublished - Oct 2007


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 dual-mode dual-band responses. Novel feeding structures are introduced to simultaneously feed the ring resonators and conveniently control the coupling strength between resonators and feeding lines, resulting in a wide tunable range of external quality factors. Two kinds of filter configurations with compact size are proposed. Both of them provide sufficient degrees of freedom to satisfy various requirements of external qualify factors and coupling coefficients at both passbands. Therefore, the center frequencies and fractional bandwidths of both passbands can be independently tuned to desired specifications within a wide range. To verify the proposed method, four filters are implemented. The measured results exhibit dual-mode dual-band bandpass responses with high selectivity. © 2007 IEEE.

Research Area(s)

  • Bandpass filter, Compact size, Dual band, Dual mode, Feeding structure