Tunable and switchable bandpass filters using slot-line resonators

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

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Author(s)

  • J. X. Chen
  • J. Shi
  • Z. H. Bao
  • Q. Xue

Detail(s)

Original languageEnglish
Pages (from-to)25-41
Journal / PublicationProgress in Electromagnetics Research
Volume111
Publication statusPublished - 2011

Abstract

In this paper, novel uniplanar tunable and switchable bandpass filters are designed by using the centrally loaded slot-line resonator. From the voltage-wave distribution along the resonator, the appropriate location for the loading element is determined to be the center of the slot-line resonator, where the voltages of the fundamental signal and second harmonic are maximum and zero, respectively. As a result, the fundamental frequency can be tuned while the second harmonic remains almost unchanged. For the first time, the properties of the centrally-loaded slot-line resonator are analyzed by using the even- and odd-mode method, and their respective resonant frequencies are derived. The demonstrated tunable bandpass filter can give a 30.9% frequency tuning range with acceptable insertion loss when a varactor is used as the loading element. By replacing the loading varactors with PIN diodes, a switchable bandpass filter is realized in which the attenuation in the fundamental passband can be controlled. In experiments, the switchable bandpass filter exhibits a 2.13 dB insertion loss in the fundamental passband when the PIN diodes are off and more than 49 dB isolation across the passband when the PIN diodes are on.

Research Area(s)

Citation Format(s)

Tunable and switchable bandpass filters using slot-line resonators. / Chen, J. X.; Shi, J.; Bao, Z. H.; Xue, Q.

In: Progress in Electromagnetics Research, Vol. 111, 2011, p. 25-41.

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