Skip to main content
Article
Licensed
Unlicensed Requires Authentication

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

  • EMAIL logo , and
Published/Copyright: December 14, 2016
Become an author with De Gruyter Brill
Submit Manuscript Author Information
Frequenz
From the journal Frequenz Volume 71 Issue 7-8

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, 2001.10.1002/0471221619Search in 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, 2013.10.1515/freq-2012-1043Search in Google 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, 2014.10.1515/freq-2013-0113Search in 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, 2015.10.1049/el.2014.3853Search in Google 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, 2012.10.1049/el.2012.1097Search in Google 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, 2012.10.1049/el.2012.1362Search in Google 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, 2015.10.1109/LMWC.2015.2496801Search in Google 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, 2014.10.1049/el.2014.3673Search in Google Scholar

Received: 2016-4-12
Published Online: 2016-12-14
Published in Print: 2017-7-26

© 2017 Walter de Gruyter GmbH, Berlin/Boston

Articles in the same Issue

  1. Frontmatter
  3. A Microwave Tunable Bandpass Filter for Liquid Crystal Applications
  4. Design of a Balun Bandpass Filter with Asymmetrical Coupled Microstrip Lines
  5. A Compact Coplanar Waveguide (CPW)-Fed Zeroth-Order Resonant Filter for Bandpass Applications
  6. A Compact Quad-Band Bandpass Filter Based on Defected Microstrip Structure
  7. Three Pole Wideband Waveguide Bandpass Filter using Split Ring Resonator Integrated Circular Fractal Shape
  8. Compact Dual-band Bandpass Filter Based on HMSIW and DS-CSRR
  9. High Selectivity Wideband Bandpass Filter Using Stub Loaded Resonator
  10. Narrow-Band Bandpass Filter for Wireless Communication System
  11. Design and Analysis of a Triple Stop-band Filter Using Ratioed Periodical Defected Microstrip Structure
  12. Design of Microstrip Lowpass Filter with Sharp Roll-off using Elliptical and Radial Resonators
  13. A Compact Via-free Composite Right/Left Handed Low-pass Filter with Improved Selectivity
https://doi.org/10.1515/freq-2016-0111
Keywords for this article
microstrip lowpass filter; LC equivalent circuit; transfer function; elliptical and radial resonators

Articles in the same Issue

  1. Frontmatter
  3. A Microwave Tunable Bandpass Filter for Liquid Crystal Applications
  4. Design of a Balun Bandpass Filter with Asymmetrical Coupled Microstrip Lines
  5. A Compact Coplanar Waveguide (CPW)-Fed Zeroth-Order Resonant Filter for Bandpass Applications
  6. A Compact Quad-Band Bandpass Filter Based on Defected Microstrip Structure
  7. Three Pole Wideband Waveguide Bandpass Filter using Split Ring Resonator Integrated Circular Fractal Shape
  8. Compact Dual-band Bandpass Filter Based on HMSIW and DS-CSRR
  9. High Selectivity Wideband Bandpass Filter Using Stub Loaded Resonator
  10. Narrow-Band Bandpass Filter for Wireless Communication System
  11. Design and Analysis of a Triple Stop-band Filter Using Ratioed Periodical Defected Microstrip Structure
  12. Design of Microstrip Lowpass Filter with Sharp Roll-off using Elliptical and Radial Resonators
  13. A Compact Via-free Composite Right/Left Handed Low-pass Filter with Improved Selectivity
Downloaded on 19.4.2026 from https://www.degruyterbrill.com/document/doi/10.1515/freq-2016-0111/html
Scroll to top button