Some design methods for band-pass filters based on halfwavelength resonators have been proposed. The main feature of these methods is that n or n + 1 transmission zeros can be generated for a structure composed of n resonators. To demonstrate the usefulness of the proposed filter structures, three kinds of two-pole compact microstrip hairpin filters are designed and fabricated. Good agreement between measured and simulated data has been demonstrated.
2. Cameron, R. J., "General coupling matrix synthesis methods for Chebyshev filtering function," IEEE Trans. Microwave Theory Tech., Vol. 47, No. 4, 433-442, 1999.
3. Amar, S. and J. Bornemann, Maximum number of finite transmission zeros of coupling resonator filters with source/load multi-resonator coupling and a given topology, Microwave Conference, 1175-1177, 2000.
4. Montejo-Garai, J. R., "Synthesis of N-even order symmetric filters with N transmission zeros by means of source-load cross coupling," Electron. Lett., Vol. 36, No. 3, 232-233, 2000.
5. Ni, D., Y. Zhu, and Y. Xie, "Design of hexagonal filter with sourceload coupling," Electron. Lett., Vol. 42, No. 23, 1355-1356, 2006.
6. Ni, D., Y. Zhu, Y. Xie, and P. Wang, "Synthesis and design of compact microwave filters with direct source-load coupling," J. of Electromagn. Waves and Appl., Vol. 20, No. 13, 1875-1885, 2006.
7. Matsuo, M., et al., "Coupling characteristics between two orthogonal resonant modes of a ring resonator," Technical report of IECE, 37-42, 1995.
8. Wada, K. and I. Awai, "A CPW resonator BPF with multiple attenuation poles and its miniaturization," IEEE 1999 MTT-S Digest, 1139-1142, 1999.
9. Hsieh, L.-H. and K. Chang, "Tunable microstrip bandpass filters with two transmission zeros," IEEE Trans. Microwave Theory Tech., Vol. 51, No. 2, 520-525, 2003.
10. Tsai, C.-M., S.-Y. Lee, and C.-C. Tsai, "Performance of a planar filter using a 00 feed structure," IEEE Trans. Microwave Theory Tech., Vol. 50, No. 10, 2362-2367, 2002.
11. Hennings, A., E. Semouchkina, A. Baker, and G. Semouchkin, "Design optimization and implementation of bandpass filters with normally fed microstrip resonators loaded by high-permittivity dielectric," IEEE Trans. Microwave Theory Tech., Vol. 54, No. 3, 1253-1261, 2006.
12. Amari, S., G. Taeson, J. Cihlar, and U. Rosenberg, "New parallel 2-microstrip line filters with transmission zeroes at finite freqiencies," 2003 IEEE M7TS Int. Microwave Symp. Dig. FIV- 27, 543-546, 2003.
13. Quendo, C., E. Rius, and C. Person, "Narrow bandpass filters using dual behavior resonators based on stepped-impedance stubs and different length stubs," IEEE Trans. Microwave Theory Tech., Vol. 52, No. 3, 1034-1044, 2004.
14. Kuo, J.-S. and E. Shih, "Microstrip stepped impedance bandpass filter with optimal rejection bandwidth," IEEE Trans. Microwave Theory Tech., Vol. 51, No. 5, 1554-1559, 2003.
15. Tsai, C.-M., S.-Y. Lee, and H.-M. Lee, "Transmission-line filters with capacitively loaded coupled lines," IEEE Trans. Microwave Theory Tech., Vol. 51, No. 5, 1517-1524, 2003.
16. Matthaei, G. L., L. Young, and E. M. T. Jones, Microwave Filters, 214-228, Impedance-Matching Networks, and Coupling Structures, 214-228, Artech House, Norwood, MA, 1980.
17. Zhang, J., B. Cui, S. Lin, and X.-W. Sun, "Sharp-rejection lowpass filter with controllable transmission zero using complementary split ring resonators (CSRRS)," Progress In Electromagnetics Research, Vol. 69, 219-226, 2007.
18. Burokur, S. N., M. Latrach, and S. Toutain, "Analysis and design of waveguides loaded with split-ring resonators," Journal of Electromagnetic Waves and Applications, Vol. 19, No. 11, 1407-1421, 2005.
19. Fu, Y. Q. and N. C. Yuan, "Reflection phase and frequency bandgap characteristics of EBG structures with anisotropic periodicity," Journal of Electromagnetic Waves and Applications, Vol. 19, No. 14, 1897-1905, 2005.