Highly Selective Dual-Mode Microstrip Bandpass Filters Using Triangular Patch Resonators

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K.G. Avinash
I. S. Rao


In this paper, highly selective dual-mode microstrip bandpass filters are proposed using horizontal and vertical slots formed on the surface of a triangular patch. Slots are responsible for splitting and coupling of dual degenerate modes and also facilitate in controlling their resonant frequencies by varying the dimensions of the slots. Horizontal and vertical slots reroute the direction of the flow of current on the surface of the patch, which results in switching of transmission zeros. Two 2-pole and one 4-pole dual-mode filters are designed, simulated and fabricated. Two pole filters have transmission zeros on side of the passband and four pole filter have transmission zeros on both sides of the passband. The designed filters exhibit a fractional bandwidth of less than 7 % and there is a good agreement between simulated and measured results.


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Avinash, K., & Rao, I. S. (2017). Highly Selective Dual-Mode Microstrip Bandpass Filters Using Triangular Patch Resonators. Advanced Electromagnetics, 6(1), 77-84. https://doi.org/10.7716/aem.v6i1.469
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  1. R.R Mansour, "Design of superconductive multiplexers using single mode and dual mode filters," IEEE Trans. Microwave Theory Tech., Vol. 42, pp. 1411- 1418, 1994.
    View Article

  2. J.S. Hong and M.J. Lancaster, "Microstrip cross-coupled trisection bandpass filters with asymmetric frequency characteristics," IEE Proc. Microwave, Antennas Propag., Vo. 146, pp. 84-90, 1999.
    View Article

  3. G.M. Erylimaz, C. Karpuz and A. Gorur, "Dual-Mode microstrip filters with adjustable transmission zeros," IET Microw. Antennas Propag., Vol. 2, pp. 839-847, 2008.
    View Article

  4. I. Wolff, "Microstrip bandpass filter using degenerate modes of a microstrip ring resonator," Electronic Lett., Vol. 8, pp. 302–303, 1972.
    View Article

  5. J.S. Hong and M.J. Lancaster, "Bandpass characteristics of new dual mode microstrip square loop resonators," Electronics Lett., Vol. 31, pp. 891-892, 1995.
    View Article

  6. C. Lugo and J. Papapolymerou, "Bandpass filter design using a microstrip triangular loop resonator with dual mode operation," IEEE Microwave Wireless Compo. Lett., Vol. 15, pp. 475-477, 2005.
    View Article

  7. J.S. Hong and M.J. Lancaster, "Microstrip bandpass filter using degenerate modes of a novel meander loop resonator," IEEE Microwave Guided wave Lett., Vol. 2, pp. 371-372, 1995.
    View Article

  8. J.A. Curtis and S.J. Fiedziuszko, "Miniature dual mode microstrip filters," IEEE MTT-S Dig., pp. 443-446, 1991.
    View Article

  9. J.S. Hong and M.J. Lancaster, "Microstrip triangular patch resonator filters," IEEE MTT- S Dig., pp. 331-334, 2001.

  10. J.S. Hong and Shuzhou Li, "Theory and experiment of dual mode microstrip triangular patch resonators and filters," IEEE Trans. Microwave Theory Tech., Vol. 52, pp. 1237-1243, 2004.
    View Article

  11. J.-K. Xiao, Q.-X. Chu and S. Zhang, "Novel microstrip triangular resonator bandpass filter with transmission zeros and wide bands using fractal-shaped defection," Progress in Electromagnetic Research, Vol. 77, pp. 343-356, 2007.
    View Article

  12. J.-K. Xiao, Q.-X. Chu and H.-F. Huang, "Triangular resonator bandpass filter with tunable operation," Progress in Electromagnetic Research, Vol. 2, pp. 167-176, 2008.
    View Article

  13. A.R.H. Alahwari.and A. Ismail, "Compact wideband bandpass filter using single corners-cut isosceles triangular patch resonator," Progress in Electromagnetic Research C, Vol. 14, pp. 227-237, 2010.
    View Article

  14. A. Boutejdar, A. Elsherbini, A. Balalem, J. Machacand A. S. Omar, "Design of new DGS hairpin microstrip bandpass filter using coupling matrix method", Proc. PIERS'2007, Prague, pp. 261-265, 2007.

  15. A. Boutejdar, A.A. Ibrahim, W.A.E. Ali, "Design of compact size and tunable bandpass filter for WLAN applications," Electronics Letters, Vol. 52, No. 24, pp. 1996-1997, 2016.
    View Article

  16. A. Boutejdar, "A new approach to design compact tunable BPF starting from simple LPF topology using a single T-DGS-resonator and ceramic capacitors", Microwave and Optical Technology Letters, Vol. 58, No.5, pp. 1142-1148, 2016.
    View Article

  17. A. Boutejdar, "Design of 5 GHz-compact reconfigurable DGS-bandpass filter using varactor-diode device and coupling matrix technique, Microwave and Optical Technology Letters, Vol, 58, No. 2, pp. 304-309, 2016.
    View Article

  18. R. Garg, P. Bhartia, I. Bahl, Microstrip Antenna Design Handbook, Boston-London: Artech House, 2001. pp. 429-430.

  19. Lei Zhu, P-M Wecowski and Ke Wu, "New planar dual-mode filter using cross-slotted patch resonator for simultaneous size and loss reduction", IEEE Trans. Microw. Theory Tech., Vol. 47, No. 5, pp. 650-654, May 1999.
    View Article

  20. S.R. Zinka, Akhilesh Mohan and Animesh Biswas, "Bandpass filter realization using degenerate dual-modes of a new type of patch resonator for significant size reduction", Proceedings of Asia Pacific Microwave Conference, pp. 1-4, 2007.

  21. Y.K. Singh and Ajay Chakrabarty, "Miniaturized dual-mode circular patch bandpass filters with wide harmonic separation", IEEE Microw. Wireless Compo., Vol. 18, pp. 584-586, Sept. 2008.