volume | PIER Journals

Abstract

A new type of miniaturized stepped impedance resonator (SIR) for bandpass filter applications is proposed in this paper. The new resonator incorporates a ground plane window with a floating conductor in the backside of the substrate. The ground plane window increase the characteristic impedance of the lines used to implement the inductive region of the quasi-lumped resonator, thus allowing some size reduction. Moreover, the presence of a floating conducting patch printed below the capacitive region of the resonator pushes up the first spurious band of the filter. A meaningful improvement of its out-of-band rejection level is then achieved. The coupling between adjacent resonators is also enhanced thus leading to wider achievable bandwidths. Some filter designs using the new resonator and other standard resonators are included for comparison purposes.

1. Nedil, M., T. A. Denidni, A. Djaiz, and H. Boutayeb, "ULtra-wideband bandpass filters using multilayer slot coupled transitions," Journal of Electromagnetic Waves and Applications, Vol. 22, No. 4, 501-516, 2008.
doi:10.1163/156939308784150353 Google Scholar

2. Zhang, X.-C., J. Xu, and Z.-Y. Yu, "Design of quasi-elliptic bandpass filter based on slow-wave open-loop resonators," Journal of Electromagnetic Waves and Applications, Vol. 22, 1849-1856, 2008.
doi:10.1163/156939308786375091 Google Scholar

3. Razalli, M. S., A. Ismail, M. A. Mahdi, and M. N. Hamidon, "Novel compact ``via-less" ultra wideband filter utilizing capacitive microstrip patch," Progress In Electromagnetics Research, Vol. 88, 91-104, 2008.
doi:10.2528/PIER08102303 Google Scholar

4. AlHawari, A. R. H., A. Ismail, M. F. A. Rasid, R. S. A. R. Abdulah, B. K. Esfeh, and H. Adam, "Compact microstrip bandpass filter with sharp passband skirts using square spiral resonators and embedded resonators," Journal of Electromagnetic Waves and Applications, Vol. 23, 675-683, 2009.
doi:10.1163/156939309788019895 Google Scholar

5. Yu, W.-H., J.-C. Mou, X. Li, and X. Lv, "A compact filter with sharp transition and wideband rejection using the novel defected ground structure," Journal of Electromagnetic Waves and Applications, Vol. 23, 329-340, 2009.
doi:10.1163/156939309787604454 Google Scholar

6. Razalli, M. S., A. Ismail, M. A. Mahdi, and M. N. Hamidon, "Novel compact ``via-less" ultra wideband filter utilizing capacitive microstrip patch," Progress In Electromagnetics Research, Vol. 91, 213-227, 2009.
doi:10.2528/PIER09020403 Google Scholar

7. Tao, Y., M. Tamura, and T. Itoh, "Compact hybrid resonator with series and shunt resonances used in miniaturized filters and balun filters," IEEE Trans. on Microwave Theory and Tech., Vol. 58, 390-402, 2010. Google Scholar

8. Cohn, S. B., "Parallel-coupled transmission-line resonator filters," IRE Trans. on Microwave Theory and Tech., Vol. 6, 223-231, 1958.
doi:10.1109/TMTT.1958.1124542 Google Scholar

9. Crystal, E. G. and S. Frankel, "Hairpin-line and hybrid hairpin-line/half-wave parallel-coupled-line filters," IEEE Trans. on Microwave Theory and Tech., Vol. 20, 719-728, 1972.
doi:10.1109/TMTT.1972.1127860 Google Scholar

10. Hong, J. S. and M. J. Lancaster, "Couplings of microstrip square open loop resonators for cross-coupled planar microwave filters," IEEE Trans. on Microwave Theory and Tech., Vol. 44, 2099-2018, 1996.
doi:10.1109/22.543968 Google Scholar

11. Sagawa, M., K. Takahashi, and M. Makimoto, "Miniaturized hairpin resonator filters and their application to receiver front-end MIC's," IEEE Trans. on Microwave Theory and Tech., Vol. 37, 1991-1997, 1989.
doi:10.1109/22.44113 Google Scholar

12. Hong, J. S. and M. J. Lancaster, "Theory and experiment of novel microstrip slow-wave open-loop resonator filters," IEEE Trans. on Microwave Theory and Tech., Vol. 45, 2358-2365, 1997.
doi:10.1109/22.643844 Google Scholar

13. Gu, J., F. Zhang, C. Wang, Z. Zhang, M. Qi, and X. Sun, "Miniaturization and harmonic suppression open-loop resonator bandpass filter with capacitive terminations," IEEE Intnal. Microwave Symposium, San Francisco (CA, USA), 373-376, 2006.

14. Packiaraj, D., M. Ramesh, and A. T. Kalghatgi, "Design of a trisection folded SIR filter," IEEE Microwave and Wireless Comp. Lett., Vol. 16, 317-319, 2006.
doi:10.1109/LMWC.2006.873459 Google Scholar

15. Akkaraekthalin, P. and J. Jantree, "Microstrip slow-wave open-loop slow resonator filters with reduced size and improvedIn conclusion stopband characteristics," ETRI Journal, Vol. 28, 607-614, 2006.
doi:10.4218/etrij.06.0106.0007 Google Scholar

16. Wang, Y. X., "Microstrip cross-coupled tri-section stepped-impedance bandpass filter with wide stop-band performance," Journal of Electromagnetic Waves and Applications, Vol. 23, 289-296, 2009.
doi:10.1163/156939309787604391 Google Scholar

17. Wang, J. P., B. Z. Wang, Y. X. Wang, and Y. X. Guo, "Dual-band miceostrip stepped-impedance bandpass filter with defected ground structure," Journal of Electromagnetic Waves and Applications, Vol. 22, No. 4, 463-470, 2008.
doi:10.1163/156939308784150335 Google Scholar

18. Sheta, A. F., "A novel compact degenerate dual-mode square patch filter using cross H-shaped defected ground structure," Journal of Electromagnetic Waves and Applications, Vol. 22, 1913-1923, 2008.
doi:10.1163/156939308787537928 Google Scholar

19. Guo, Y. C., L. H. Weng, and X. W. Shi, "An improved microstrip open-loop resonator bandpass filter with DGSS for WLAN applications," Journal of Electromagnetic Waves and Applications, Vol. 23, 463-472, 2009.
doi:10.1163/156939309787612301 Google Scholar

20. Packiaraj, D., K. J. Vinoy, and A. T. Kalghatgi, "Analysis and design of two layered ultra wide band filter," Journal of Electromagnetic Waves and Applications, Vol. 23, 1235-1243, 2009. Google Scholar

21. Quendo, C., E. Rius, C. Person, and M. Ney, "Integration of optimized low-pass filters in a bandpass filter for out-of-band improvement," IEEE Trans. on Microwave Theory and Tech., Vol. 49, 2376-2383, 2001.
doi:10.1109/22.971624 Google Scholar

22. Sun, S. and L. Zhu, "Stopband-enhanced and size-miniaturized low-pass filters using high-impedance property of offset finite-ground microstrip line," IEEE Trans. on Microwave Theory and Tech., Vol. 53, 2844-2850, 2005. Google Scholar

23. Velazquez-Ahumada, M. C., J. Martel, and F. Medina, "Design of compact low-pass elliptic filters using double-side MIC technology," IEEE Trans. on Microwave Theory and Tech., Vol. 55, 121-127, 2007.
doi:10.1109/TMTT.2006.888578 Google Scholar

24. Zhang, W., L. Han, R. Ma, and J. Mao, "Multiharmonic supression band-pass filter for communication system," ETRI Journal, Vol. 29, 533-535, 2007.
doi:10.4218/etrij.07.0207.0022 Google Scholar

25. Garcia, J., J. Bonache, I. Gil, F. Martn, M. C. Velazquez, and J. Martel, "Miniaturized microstrip and CPW filters using coupled metamaterial resonators," IEEE Trans. on Microwave Theory and Tech., Vol. 54, 2628-2635, 2006.
doi:10.1109/TMTT.2006.872934 Google Scholar

26. Masot, F., F. Medina, and M. Horno, "Analysis and experimental validation of a type of three-microstrip directional coupler," IEEE Trans. on Microwave Theory and Tech., Vol. 42, 1624-1631, 1994.
doi:10.1109/22.310555 Google Scholar

27. Velazquez-Ahumada, M. C., J. Martel, and F. Medina, "Parallel coupled microstrip filters with floating ground-plane conductor for spurious-band suppression," IEEE Trans. on Microwave Theory and Tech., Vol. 53, 1823-1828, 2005.
doi:10.1109/TMTT.2005.847083 Google Scholar

28. Lee, S. Y. and C. M. Tsai, "New cross-coupled filter design using improved hairpin resonator," IEEE Trans. on Microwave Theory and Tech., Vol. 48, 2482-2490, 2000. Google Scholar

29. Zhu, J. and Z. Feng, "Microstrip interdigital hairpin resonator with an optimal physical length," IEEE Microwave and Wireless Comp. Letters, Vol. 16, 672-674, 2006.
doi:10.1109/LMWC.2006.885622 Google Scholar

30. Makimoto, M. and S. Yamashita, Microwave Resonators and Filters for Wireless Communication, Springer Series in Advanced Electromagnetics, New York, 2001.

31. Lee, S.-Y., "Optimum resonant conditions of stepped impedance resonators," European Microwave Conference, 2005.

32. Martel, J. and F. Medina, "A suitable integral equation for the quasi-TEM analysis of hybrid strip/slot-like structures," IEEE Trans. on Microwave Theory and Tech., Vol. 49, 224-228, 2001.
doi:10.1109/22.900016 Google Scholar

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

Dr. Maria Velazquez-Ahumada

Professor Jesus Martel-Villagran

Prof. Francisco Medina

Prof. Francisco Mesa