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Frequenz

Journal of RF-Engineering and Telecommunications

Editor-in-Chief: Jakoby, Rolf


IMPACT FACTOR 2017: 0.280
5-year IMPACT FACTOR: 0.297

CiteScore 2017: 0.38

SCImago Journal Rank (SJR) 2017: 0.128
Source Normalized Impact per Paper (SNIP) 2017: 0.243

Online
ISSN
2191-6349
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Volume 71, Issue 7-8

Issues

Design of Microstrip Lowpass Filter with Sharp Roll-off using Elliptical and Radial Resonators

Gholamreza Karimi / Saeedeh Lotfi / Hesam Siahkamari
  • Young Researchers and Elite Club, Kermanshah Branch, Islamic Azad University, Kermanshah, Iran
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
Published Online: 2016-12-14 | DOI: https://doi.org/10.1515/freq-2016-0111

Abstract

A new microstrip lowpass filter with sharp roll-off and high suppression level in stop-band is presented. To achieve the lowpass filter with high performance, coupled T-shaped, elliptical and radial resonators are adopted. New formulas for calculating LC equivalent circuit of elliptical and radial resonators are derived based on T-shaped resonators. Transfer functions of the resonators are calculated using the LC equivalent circuits. The designed filter with 3 dB cut-off frequency at 1.67 GHz has been fabricated and measured. Results demonstrate that a relative stop-band bandwidth (RSB) of 157 % (referred to a suppression degree of 30 dB) is obtained while achieving a sharp roll-off about 255.2 dB/GHz. The features of lowpass filter exhibit that the figure of merit is about 45372. Also good agreements are achieved between measured and simulated S-parameters of the fabricated and designed filter.

Keywords: microstrip lowpass filter; LC equivalent circuit; transfer function; elliptical and radial resonators

References

  • [1]

    J. S. Hong and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications. New York: Wiley, 2001.Google Scholar

  • [2]

    H. Sariri, Z. Rahmani, A. Lalbakhsh, and S. Majidifar, “Compact LPF using T-shaped resonator,” Frequenz, vol. 67, no. 1–2, pp. 17–20, 2013.Web of ScienceGoogle Scholar

  • [3]

    G. Karimi, M. Yazdani, H. Siahkamari, and A. Lalbakhsh, “Design of microstrip LPF with sharp cut-off frequency and wide stop-band,” Frequenz, vol. 68, no. 7–8, pp. 313–319, 2014.Google Scholar

  • [4]

    M. Hayati, M. Gholami, H. S. Vaziri, and T. Zaree, “Design of microstrip lowpass filter with wide stop-band and sharp roll-off using hexangular shaped resonator”, Electron. Lett., vol. 51, no. 1, pp. 69–71, 2015.CrossrefGoogle Scholar

  • [5]

    H. Cui, J. Wang, and G. Zhang, “Design of microstrip lowpass filter with compact size and ultra-wide stop-band”, Electron. Lett., vol. 48, no. 14, pp. 856–857, 2012.CrossrefGoogle Scholar

  • [6]

    J. Wang, H. Cui, and G. Zhang, “Design of compact microstrip lowpass filter with ultra-wide stop-band”, Electron. Lett., vol. 48, no. 14, pp. 854–856, 2012.CrossrefGoogle Scholar

  • [7]

    M. Xiao, G. Sun, and X. Li, “A lowpass filter with compact size and sharp roll-off”, IEEE Microw. Wirel. Compon. Lett., vol. 25, no. 12, pp. 790–792, 2015.CrossrefWeb of ScienceGoogle Scholar

  • [8]

    S. H. Liu, J. Xu, and Zh. Xu, “Compact lowpass filter with wide stop-band using stepped impedance hairpin units”, Electron. Lett., vol. 50, no. 10, pp. 67–69, 2014.Google Scholar

About the article

Received: 2016-04-12

Published Online: 2016-12-14

Published in Print: 2017-07-26


Citation Information: Frequenz, Volume 71, Issue 7-8, Pages 349–356, ISSN (Online) 2191-6349, ISSN (Print) 0016-1136, DOI: https://doi.org/10.1515/freq-2016-0111.

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