Microstrip hairpin bandpass filter using modified minkowski fractal-shape for suppression of second harmonic

Ali Lalbakhsh*, Abbas Ali Lotfi Neyestanak, Mohammad Naser-Moghaddasi

*Corresponding author for this work

Research output: Contribution to journalArticle

18 Citations (Scopus)


In this paper, a novel microstrip hairpin-line bandpass filter which employs a modified Minkowski fractal shape is proposed. Although conventional hairpin-line filters are popular for RF front ends, they suffer from undesired spurious responses located at the second harmonic, which causes asymmetry in the upper skirt band. By proper design, the second harmonic of fractal filters can be significantly suppressed through the use of fractal shape. To validate this novel geometry, the proposed filters are fabricated and measured. Simulated results are in good agreement with measured results.

Original languageEnglish
Pages (from-to)378-381
Number of pages4
JournalIEICE Transactions on Electronics
Issue number3
Publication statusPublished - 2012
Externally publishedYes



  • Fractal
  • Microstrip filter
  • Second harmonic suppression

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