Wide tunable range bandpass filter with three transmission zeros

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

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  • Mingen Tian
  • Zhihe Long
  • Lijun Feng
  • Leilei He
  • Tianliang Zhang

Related Research Unit(s)


Original languageEnglish
Article numbere23350
Journal / PublicationInternational Journal of RF and Microwave Computer-Aided Engineering
Issue number11
Online published11 Aug 2022
Publication statusPublished - Nov 2022


This paper proposes a reconfigurable bandpass filter with a wide tunable range, which is achieved by connecting two tunable passbands with switching diodes. A pair of transmission zeros (TZs) are introduced through the cross-coupling structure to improve the passband selectivity of the filter, and one more transmission zero is added by the interdigital coupling line to enhance the out-of-band suppression and broaden the upper stopband. The simulation and experimental results show that the designed filter with an absolute bandwidth of 100 MHz realizes a tunable frequency band covering 1.5–3 GHz, corresponding to a fractional tunable range of 66.7%. The dimension of the fabricated filter is 0.32 λg × 0.34 λg.

Research Area(s)

  • bandpass, reconfigurable filter, switching diode, transmission zero, wide tunable range