Journal of electromagnetic engineering and science

The Korean Institute of Electromagnetic Engineering and Science (한국전자파학회)
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A Design of Varactor-Tuned Combline Bandpass Filter Using Coupling Varactor Diode

  • Kim Byung-Wook (Dept. of Electronic Engineering, Sogang University) ;
  • Back Hyung-Il (Dept. of Electronic Engineering, Sogang University) ;
  • Yun Sang-Won (Dept. of Electronic Engineering, Sogang University)
  • Published : 2005.06.01
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Abstract

In this paper, a novel varactor-tuned combline bandpass filter is presented. The coupling varactor diode between line elements is introduced to control the passband bandwidth so that the passband bandwidth can be maintained almost constant within the tuning range. The equivalent circuit and design equations are derived, and the optimum design is discussed. A 1.7 GHz, two-pole bandpass filter with a bandwidth of $4.5\%$ was constructed. The absolute passband bandwidth was maintained almost constant within more than 0.4 octave tuning range.

Keywords

References

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