volume | PIER Journals

Abstract

A new class of microstrip filter structures are designed, optimized, simulated and measured for ultra-narrowband performance essential to the wireless industry applications. More accurate model of the coupling coefficient is outlined and tested for narrowband filter design. Two sample filters are fabricated and measured to verify the simulations and prove the concept. The idea behind the new designs is based on minimizing the parasitic couplings within the resonators and the inter-resonator coupling of adjacent resonators. A reduction of the overall coupling coefficient is achieved even with less resonator separation which is a major issue for compactness of such filters. The best new designs showed a simulated fractional bandwidth (FBW) of 0.05% and 0.02% with separations of S = 0.63 mm and S = 0.45 mm, respectively. The measured filters tend to have even narrower FBW than the simulated, though its insertion loss deteriorates, possibly due to mismatch at the interface with external circuitry and poor shielding effect of the test platform. The investigated 2-pole filters are accommodated on a compact area of a nearly 0.6 cm². An improvement of tens of times of order in narrowband performance is achieved compared to reported similar configuration filters and materials. A sharp selectivity and quasi-elliptic response are also demonstrated with good agreement in both simulations and measurements. In all filters, however, the study shows that the narrower the FBW, the larger the insertion loss (IL) and the worse the return loss (RL). This is confirmed by measurements.

1. Mtthaei, G. L., N. O. Fenzi, R. J. Forse, and S. M. Rohlfing, "Hairpin-comp filter for HTS and other narrow-band applications," IEEE Transactions on Microwave Theory and Techniques, Vol. 45, No. 8, 1226-1231, 1997.
doi:10.1109/22.618411 Google Scholar

2. 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

3. Yu, C.-C. and Y. K. Chang, "Novel compact elliptic-function narrow-band bandpass filters using microstrip open-loop resonators with coupled and crossing lines," IEEE Transactions on Microwave Theory and Techniques, Vol. 46, No. 7, 952-958, 1998.
doi:10.1109/22.701448 Google Scholar

4. Hong, J.-S. and M. J. Lancaster, "Aperture-coupled microstrip open-loop resonators and their applications to the design of novel microstrip bandpass filters," IEEE Transactions on Microwave Theory and Techniques, Vol. 47, No. 9, 1848-1855, 1999.
doi:10.1109/22.788522 Google Scholar

5. Hong, J.-S., M. J. Lancaster, D. Jedamzik, and R. B. Greed, "On the development of superconducting microstrip filters for mobile communications applications," IEEE Transactions on Microwave Theory and Techniques, Vol. 47, No. 9, 1656-1663, 1999.
doi:10.1109/22.788606 Google Scholar

6. Kim, H. T., B.-C. Min, Y.-H. Choi, S.-H. Moon, S.-M. Lee, B. Oh, J.-T. Lee, I. Park, and C.-C. Shin, "A compact narrowband HTS microstrip filter for PCS applications," IEEE Transactions on Applied Superconductivity, Vol. 9, No. 2, 3909-3912, 1999.
doi:10.1109/77.783882 Google Scholar

7. Hejazi, Z. M., P. S. Excell, and Z. Jiang, "Compact dual-mode filters for HTS satellite communication systems," IEEE Microwave and Guided Wave Letters, Vol. 8, No. 8, 275, 1998.
doi:10.1109/75.704412 Google Scholar

8. Hejazi, Z. M., Z. Jiang, and P. S. Excell, "Lumped-element microstrip narrow bandpass tunable filter using varactor-loaded inductors," International Journal of Electronics, Vol. 90, No. 1, 57-63, 2003.
doi:10.1080/0020721031000147327 Google Scholar

9. Jeon, B. K., J. H. Kim, C. J. Lee, B. C. Min, Y. H. Choi, S. K. Kim, and B. Oh, "A novel HTS microstrip quasi-elliptic function bandpass filter using pseudo-lumped element resonator," IEEE MTT-S International Microwave Symposium Digest, Vol. 2, 1197-1200, 2000. Google Scholar

10. Reppel, M., Novel HTS microstrip resonator configurations for microwave bandpass filters, Doctoral dissertation, Bergish University, Wuppertal, Germany, 2000.

11. Vendik, I. B., A. N. Deleniv, V. O. Sherman, A. A. Svishchev, V. V. Kondratiev, D. V. Kholodniak, A. V. Lapshin, P. N. Yudin, B.-C. Min, Y. H. Choi, and B. Oh, "Narrowband Y-Ba-Cu-O filter with quasi-elliptic characteristic," IEEE Transactions on Applied Superconductivity, Vol. 11, No. 1, 477-480, 2001.
doi:10.1109/77.919386 Google Scholar

12. Matthaei, G. L., "Narrow-band, fixed-tuned, and tunable bandpass filters with zig-zag hairpin-comb resonators," IEEE Transactions on Microwave Theory and Techniques, Vol. 51, No. 4, 1214-1219, 2003.
doi:10.1109/TMTT.2003.809631 Google Scholar

13. Sheng, Y. and S. Carles, "New advances in HTS microstrip filter design," IEEE MTT-S International Microwave Symposium Digest, Vol. 3, 1885-1888, 2003. Google Scholar

14. Yi, H. R., S. K. Remillard, and A. Abdelmonem, "A superconducting thin film filter of very high wide-band rejection," IEEE MTT-S International Microwave Symposium Digest, Vol. 3, 1893-1896, 2003. Google Scholar

15. Dustakar, K. and S. Berkowitz, "An ultra-narrowband HTS band-pass filter," IEEE MTT-S International Microwave Symposium Digest, Vol. 3, 1881-1884, 2003. Google Scholar

16. Zhou, J., M. J. Lancaster, and F. Huang, "Superconducting microstrip filter using compact resonators with double-spiral inductors and interdigital capacitors," IEEE MTT-S International Microwave Symposium Digest, Vol. 3, 1889-1892, 2003. Google Scholar

17. Hasan, A. and A. E. Nadeem, "Novel microstrip hairpinline narrowband bandpass filter using via ground holes," Progress In Electromagnetics Research, Vol. 78, 393-419, 2008.
doi:10.2528/PIER07091401 Google Scholar

18. 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

19. 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

20. 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

21. 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

22. 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

23. 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

24. 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

25. Moghadasi, S. M., A. R. Attari, and M. M. Mirsalehi, "Compact and wideband 1-D mushroom-like EBG filters," Progress In Electromagnetics Research, Vol. 83, 323-333, 2008.
doi:10.2528/PIER08050101 Google Scholar

26. Wang, X.-H., B.-Z. Wang, and K. J. Chen, "Compact broadband dual-band bandpass filters using slotted ground structures," Progress In Electromagnetics Research, Vol. 82, 151-166, 2008.
doi:10.2528/PIER08030101 Google Scholar

27. Naghshvarian-Jahromi, M. and M. Tayarani, "Miniature planar UWB bandpass filters with circular slots in ground," Progress In Electromagnetics Research Letters, Vol. 3, 87-93, 2008. Google Scholar

28. Hejazi, Z. M. and A. Omar, "Modeling and simulation of novel ultra-narrowband miniature microstrip filters for mobile and wireless critical applications," Microwave & Optical Technology Letters, Vol. 45, No. 1, 35-39, 2005.
doi:10.1002/mop.20715 Google Scholar

29. Hejazi, Z. M. and Z. Jiang, "A new model to calculate the coupling coefficient for more accurate filter design and further development of narrowband-filter performance," Microwave & Optical Technology Letters, Vol. 47, No. 2, 180-185, 2005.
doi:10.1002/mop.21118 Google Scholar

30. Sonnet User’s manuals for em and related software, release 9, Sonnet Software, Inc., North Syracuse, NY, USA, 2003.

31. Grounds, P. W. and K. A. Zaki, "Analysis of the coupling between degenerate modes of enclosed rectangular microstrip patches," Journal of Electromagnetic Waves and Applications, Vol. 9, No. 11-12, 1503-1516, 1995.
doi:10.1163/156939395X00181 Google Scholar

32. Jiang, Z., Z. M. Hejazi, P. S. Excell, and W. Y. Xu, "A new HTS microwave filter using dual-mode multi-zigzag microstrip loop resonators," IEEE Asia Pacific Microwave Conference, Vol. 3, 813, November 30-December 3 1999. Google Scholar

33. Hejazi, Z. M. Superconducting planar resonators and filters, Doctoral dissertation, University of Bradford, Bradford, UK, 1998.

34. Agilant Rf and microwave appCAD software, www.hp.woodshot.com/appcad/appcad.htm, 2004.

35. Rautio, J. C. and V. Demir, "Microstrip conductor loss models for electromagnetic analysis," IEEE Transactions on Microwave Theory and Techniques, Vol. 51, No. 3, 915-921, 2003.
doi:10.1109/TMTT.2003.808693 Google Scholar

36. Matthaei, G. L., L. Young, and E. M. T. Jones, Microwave Filters, Impedance Matching Networks, and Coupling Structures, Artech House, 1980.

Dr. Zuhair Hejazi

Dr. Maximilian C. Scardelletti

Dr. Frederick W. Van Keuls

Dr. Amjad Omar

Prof. Ayman Sulaiman Al-Zayed