A novel and compact ultra wideband (UWB) bandpass filter (BPF) with two transmission zeros near both passband edges of lower and higher frequency is proposed by using a new structure of fork-formresonators. The fork-formresonator generates a attenuation pole at the higher passband edge, lower insertion loss, wider bandwidth and compacter dimension, as compared with the traditional parallel unilateral-coupled resonator. A microstrip bandpass filter cascaded by two stages fork-formresonators with a 3-dB fractional bandwidth of 128% (from1.0 GHz to 4.6 GHz) is designed, fabricated, and tested. The measured characteristics of the filter agree with the theoretical simulations, and the measured results show good specifications which are very low insertion loss 0.5±0.3 dB within the passband and good return loss less than −15 dB from1.5 GHz to 4.0 GHz, respectively.
"A Novel and Compact UWB Bandpass Filter Using Microstrip Fork-Form Resonators," ,
Vol. 77, 273-280, 2007. doi:10.2528/PIER07082302
1. Skolnik, M., G. Andrews, and J. P. Hansen, "Ultra wideband microwave-radar conceptual design," IEEE Trans. Aerosp. Electron. Syst., Vol. 10, 25-30, 1995.
2. Hamalainen, M., V. Hovinen, R. Tesi, J. H. J. Iinatti, and M. Latva-Aho, "On the UWB systemco existence with GSM 900, UMTS/WCDMA, and GPS," IEEE J. Sel. Area Commun., Vol. 20, 1712-1721, 2002. doi:10.1109/JSAC.2002.805242
3. Kharakhili, F. G., M. Fardis, G. Dadashzadeh, and A. Ahmadi, "Circular slot with a novel circular microstrip open ended microstrip feed for UWB applications," Progress In Electromagnetics Research, Vol. 68, 161-167, 2007. doi:10.2528/PIER06071901
4. Zhu, L., S. Sun, and W. Menzel, "Ultra-wideband (UWB) bandpass filters using multiple-mode resonator," IEEE Microwave and Wireless Components Letters, Vol. 15, No. 11, 796-798, 2005. doi:10.1109/LMWC.2005.859011
5. Gorur, A. and C. Karpuz, "Uniplanar compact wideband bandstop filter," IEEE Microwave Wireless Component Letter, Vol. 13, 114-116, 2003. doi:10.1109/LMWC.2003.810114
6. Prabhu, S. and J. S. Mandeep, "Microstrip bandpass filter at S band using capacitive coupled resonator," Progress In Electromagnetics Research, Vol. 76, 223-228, 2007. doi:10.2528/PIER07071205
7. Xiao, J.-K. and Y. Li, "Novel compact microstrip square ring bandpass filter," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 13, 1817-1826, 2006. doi:10.1163/156939306779292156
8. Fan, J.-W., C.-H. Liang, and X.-W. Dai, "Design of cross-coupled dual-band filter with equal-length spilt-ring resonators," Progress In Electromagnetics Research, Vol. 75, 285-293, 2007. doi:10.2528/PIER07060904
10. Cohn, S. B., "Parrallel coupled transmission line resonator filters," IEEE Trans. Microwave Theory Tech., Vol. MTT-6, 223-231, 1958. doi:10.1109/TMTT.1958.1124542
11. Kajfez, D. and S. Govind, "Effect of difference in odd-and even-mode wavelengths on a parallel-coupled bandpass filter," Electronics Letters, Vol. 11, No. 5, 117-118, 1975. doi:10.1049/el:19750088
12. Lin, C. J., C.-C. Chiu, S.-G. Hsu, and H. C. Liu, "A novel model extraction algorithmfor reconstruction of coupled transmission lines in high-speed digital system," Journal of Electromagnetic Waves and Applications, Vol. 19, No. 12, 1595-1609, 2005. doi:10.1163/156939305775537393
13. Wang, B.-Z., X.-H. Wang, and J.-S. Hong, "On the generalized transmission-line theory," Journal of Electromagnetic Waves and Applications, Vol. 19, No. 3, 413-425, 2005. doi:10.1163/1569393054139697
14. Matsunaga, M., M. Katayama, and K. Yasumoto, "Coupled-mode analysis of line parameters of coupled microstrip lines," Progress In Electromagnetics Research, Vol. 24, 1-17, 1999. doi:10.2528/PIER99032902
15. Tripathi, V. K., "Asymmetric coupled transmission lines in an inhomogeneous medium," IEEE Trans. Microwave Theory Tech., Vol. MTT-23, No. 9, 734-739, 1975. doi:10.1109/TMTT.1975.1128665
16. Chen, H. and Y.-X. Zhang, "A novel compact planar six-way power divider using folded and hybrid-expanded coupled lines," Progress In Electromagnetics Research, Vol. 76, 243-252, 2007. doi:10.2528/PIER07070601
17. Tripathi, V. K., "On the analysis of symmetrical three-line microstrip circuits," IEEE Trans. Microwave Theory Tech., Vol. 25, No. 9, 726-729, 1977. doi:10.1109/TMTT.1977.1129202
18. Tripathi, V. K., Y. K. Chin, H. S. Chang, and N. Orhanovic, Coupled line multiports, Proc. IEEE Int. Symp. Circuits Syst., Vol. 2, No. 5, 1021-1024, 1992.
19. Kollipara, R. T., et al., "Modeling and design of interdigital structure," IEEE Trans. Electron Devices, Vol. 38, No. 11, 575-577, 1991. doi:10.1109/16.97430
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