Design of compact dual-band bandpass filters using λ/2 and combined λ/4 stepped-impedance resonators

Ching-Her Lee, Yi Huan Hsieh, Min-Hua Ho

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2 Citations (Scopus)


This paper presents a compact dual-band bandpass filter (BPF) that consists of a pair of L-shape half-wavelength (λ/2) stepped-impedance resonators (SIRs) and an inverted Z-shape resonator. The latter is actually a combined structure of two λ/4 SIRs along with a magnetic coupling in between and hence designed to reduce the circuit size. Cross-coupled SIR configuration and 0° tapped-feed structures are adopted to introduce attenuation poles around the passband edges for selectivity improvement. A wider -20-dB upper stopband is achieved by properly separating the third resonant frequencies of the SIRs of different types. The newly designed dual-band BPF was verified by circuit implementation, and a very good agreement between the simulated and measured results was observed.

Original languageEnglish
Pages (from-to)2703-2706
Number of pages4
JournalMicrowave and Optical Technology Letters
Issue number11
Publication statusPublished - 2007 Nov 1


All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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