volume | PIER Journals

Abstract

Abstract-In this paper, we present a novel improved hairpinline microstrip narrowband bandpass filter with via ground holes. The new filter design methodology is derived from conventional hairpinline filter design. This design methodology incorporates use of λ/8 resonators, thereby reducing the size of the filter by 35% as compared to the conventional design. An analysis is presented to show the effects of tap point height and microstrip width on fundamental parameters of filter and subsequent relationships are developed. Through use of via ground holes and a wider microstrip line for resonators, 3 dB Fractional Bandwidth (FBW) less than 2%, Insertion Loss (IL) less than 1.6 dB and Return Loss (RL) better than 40 dB is achieved with midband center frequency 1 GHz. Spurious response suppression is achieved till 3ƒ₀. Robustness of this design approach is demonstrated by designing filters on two more substrates having ε_r 2.17 and 9.2. As low as 0.48% FBW was achieved by using different substrates. The design approach is successfully tested for center frequency upto 2 GHz beyond which folding the resonator becomes practically difficult. Finally, a bandpass filter is designed with this design methodology and fabricated using FR4 substrate. S-parameter measurements show a good agreement with the simulated results.

1. Cohn, S. B., "Parallel-coupled transmission-line-resonator filters," IRE Transactions on Microwave Theory and Techniques, Vol. MTT-6, No. 4, 223-231, 1958.
doi:10.1109/TMTT.1958.1124542 Google Scholar

2. Matthaei, G. L., "Design of wide band (and narrow band) bandpass microwave filters on the IL basis," IRE Transactions on Microwave Theory and Techniques, Vol. MTT-8, No. 11, 310-314, 1960. Google Scholar

3. Chang, C. Y. and T. Itoh, "A modified parallel-coupled filter structure that improves the upper stop band rejection and response symmetry," IEEE Transactions on Microwave Theory and Techniques, Vol. 39, No. 2, 310-314, 1991.
doi:10.1109/22.102975 Google Scholar

4. Riddle, A., "High performance parallel coupled microstrip filters," IEEE Microwave Theory and Technology Symposium Digest, 427-430, 1988.

5. Akhtarzad, S., T. R. Rowbotham, and P. B. Johns, "The design of coupled microstrip lines," IEEE Transactions on Microwave Theory and Techniques, Vol. MTT-23, No. 6, 486-492, 1975.
doi:10.1109/TMTT.1975.1128605 Google Scholar

6. Pozar, D. M., Microwave Engineering, 2nd edition, 1998.

7. Collin, R. E., Foundations for Microwave Engineering, 2nd edition, 1992.

8. Cristal, E. G. and S. Frankel, "Hairpin-line and hybrid hairpinline/ half-wave parallel-coupled-line filters," IEEE Transactions on Microwave Theory and Techniques, Vol. MTT-22, No. 11, 719-728, 1972.
doi:10.1109/TMTT.1972.1127860 Google Scholar

9. Gysel, U. H., "New theory and design for hairpin-line filters," IEEE Transactions on Microwave Theory and Techniques, Vol. MTT-22, No. 5, 523-531, 1974.
doi:10.1109/TMTT.1974.1128273 Google Scholar

10. Singh, K., R. Ramasubramanian, and S. Pal, "Coupled microstrip filters: Simple methodologies for improved characteristics, communication systems group," India EESOF User Group Meeting, 2005. Google Scholar

11. Bahl, I. J., Lumped Elements for RF and Microwave Circuits, Artech House, 2003.

12. Hong, J.-S. and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications, Wiley, 2001.

13. Wong, J. S., "Microstrip tapped line filter design," IEEE Transactions on Microwave Theory and Techniques, Vol. MTT- 27, No. 1, 44-50, 1979.
doi:10.1109/TMTT.1979.1129556 Google Scholar

14. Hong, J.-S. and M. J. Lancaster, "Development of new microstrip pseudo-interdigital bandpass filters," IEEE Microwave and Guided Wave Letters, Vol. 5, No. 8, 261-263, 1995.
doi:10.1109/75.401073 Google Scholar

15. Hong, J.-S. and M. J. Lancaster, "Cross-coupled microstrip hairpin-resonator filters," IEEE Transactions on Microwave Theory and Techniques, Vol. 46, No. 1, 118-122, 1998.
doi:10.1109/22.654931 Google Scholar

16. Gu, Q., RF System Design of Transceivers for Wireless Communications, Springer, 2005.

17. Jantaree, J.S. Kerdsumang, and P. Akkaraekthalin, "A microstrip bandpass filter using a symmetrical parallel coupled-line structure," The 9th Asia Pacific Conference on Communications, Vol. 2, 784-788, 2003.

18. Deng, P.-H., Y.-S. Lin, C.-H. Wang, and C. H. Chen, "Compact microstrip bandpass filters with good selectivity and stopband rejection," IEEE Transactions on Microwave Theory and Techniques, Vol. 54, No. 2, 533-539, 2006.
doi:10.1109/TMTT.2005.862709 Google Scholar

19. Xiao, J.-K., S.-P. Li, and Y. Li, "Novel planar bandpass filters using single patch resonators with corner cuts," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 11, 1481-1493, 2006.
doi:10.1163/156939306779274327 Google Scholar

20. Zhu, Y.-Z., Y.-J. Xie, and H. Feng, "Novel microstrip bandpass filters with transmission zeros," Progress In Electromagnetics Research, Vol. 77, 29-41, 2007.
doi:10.2528/PIER07072301 Google Scholar

21. Xiao, J.-K. and Y. Li, "Novel microstrip square ring bandpass filters," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 13, 1817-1826, 2006.
doi:10.1163/156939306779292156 Google Scholar

22. Zhao, L.-P., X.-W. Chen, and C.-H. Liang, "Novel design of dual-mode dual-band bandpass filter with triangular resonators," Progress In Electromagnetics Research, Vol. 77, 417-424, 2007.
doi:10.2528/PIER07090501 Google Scholar

23. Xiao, J.-K., S.-W. Ma, S. Zhang, and Y. Li, "Novel compact split ring stepped impedance resonators (SIR) bandpass filters with transmission zeros," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 3, 329-339, 2007.
doi:10.1163/156939307779367369 Google Scholar

24. Wang, Y. X., B-Z. Wang, and J. Wang, "A compact square loop dual-mode bandpass filter with wide stop-band," Progress In Electromagnetics Research, Vol. 77, 67-73, 2007.
doi:10.2528/PIER07072707 Google Scholar

25. Xiao, J.-K., "Novel microstrip dual-mode bandpass filter using isosceles triangular patch resonator with fractal-shaped structure," Journal of Electromagnetic Waves and Applications, Vol. 21, No. 10, 1341-1351, 2007.
doi:10.1163/156939307783239500 Google Scholar

26. Swanson, D. G. and Jr., "Grounding microstrip lines with via holes," IEEE Transactions on Microwave Theory and Techniques, Vol. 40, No. 8, 1719-1721, 1992.
doi:10.1109/22.149532 Google Scholar

27. Kinayman, N. and M. I. Aksun, Modern Microwave Circuits, Artech House, 2005.

28. Pak, J. S., M. Aoyagi, K. Kikuchi, and J. Kim, "Band-stop filter effect of power/ground plane on through-hole signal via in multilayer PCB," IEICE Trans. Electron, Vol. E89-C, No. 4, 551-559, 2006.
doi:10.1093/ietele/e89-c.4.551 Google Scholar

29. Chueng, W. S. and F. H. Levien, Microwave Made Simple: Principles and Applications, Artech House Inc., 1985.

30. Agilent ADS 20005A, Momentum, Momentum, Agilent Technologies.

31. LPKF EasyContac, Operating Instructions, Operating Instructions, LPKF Laser & Electronic AG.

32. Suhner Coaxial Connectors General Catalogue, 2003/04 edition, 2003/04 edition, 123..

Dr. Azhar Hasan

Dr. Ahmed Nadeem