volume | PIER Journals

Abstract

A novel bandstop filter with wide-stopband performance is proposed and discussed in this paper. This circuit configuration includes two-section coupled lines and three open-circuit transmission-line stubs. Due to the symmetry of this proposed structure, closed-form equations for scattering parameters are investigated. Transmission zeros and poles location for different circuit parameters are discussed, and the corresponding design curves are given. In order to verify this new filter circuit structure and its corresponding design theory, several typical numerical examples are designed, calculated and illustrated. Furthermore, a practical wideband bandstop filter with -20 dB fractional bandwidth of 94% centered at 3 GHz with sharp rejection characteristics is fabricated to validate the theoretical prediction. The measured frequency response of the filter agrees excellently with the predicted result.

1. Hong, J.-S. and M. J. Landcaster, Microstrip Filters for RF/Microwave Applications, Chapter 2, Wiley, New York, 2001.
doi:10.1002/0471221619

2. Chen, H., Y.-H. Wu, Y.-M. Yang, and Y.-X. Zhang, "A novel and compact bandstop filter with folded microstrip/CPW hybrid structure," Journal of Electromagnetic Waves and Applications, Vol. 24, No. 1, 103-112, 2010.
doi:10.1163/156939310790322163 Google Scholar

3. Matthaei, G. L., L. Oung, and E. M. T. Jones, Microwave Filters, Impedance Matching Networks and Coupling Structures, McGraw Hill, 1964.

4. Pozar, D. M., Microwave Engineering, 2nd Ed., Wily, New York, 1998.

5. Wu, Y., Y. Liu, S. Li, and C. Yu, "A simple microstrip bandpass filter with analytical design theory and sharp skirt selectivity," Journal of Electromagnetic Waves and Applications, Vol. 25, No. 8-9, 1253-1263, 2011.
doi:10.1163/156939311795762060 Google Scholar

6. 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, No. 2-3, 329-340, 2009.
doi:10.1163/156939309787604454 Google Scholar

7. Wu, Y., Y. Liu, S. Li, and C. Yu, "A new wide-stopband low-pass filter with generalized coupled-line circuit and analytical theory," Progress In Electromagnetics Research, Vol. 116, 553-567, 2011. Google Scholar

8. Gomez-Garcia, R. and J. I. Alonso, "Design of sharp-rejection and low-loss wide-band planar filters using signal-interference techniques," IEEE Microw. Wireless Compon. Lett., Vol. 15, No. 8, 530-532, Aug. 2005.
doi:10.1109/LMWC.2005.852797 Google Scholar

9. Sanchez-Soriano, M. A., E. Bronchalo, and G. Torregrosa-Penalva, "Compact UWB bandpass filter based on signal interference techniques," IEEE Microw. Wireless Compon. Lett., Vol. 19, No. 11, 692-694, Nov. 2009.
doi:10.1109/LMWC.2009.2032001 Google Scholar

10. Hong, J.-S. and M. J. Lancaster, "Design of highly selective microstrip bandpass filters with a single pair of attenuation poles at finite frequencies," IEEE Trans. on Microw. Theory and Tech., Vol. 48, No. 7, 1098-1107, Jul. 2000.
doi:10.1109/22.848492 Google Scholar

11. Lee, H.-M. and C.-M. Tsai, "Improved coupled-microstrip filter impedances," IEEE Trans. on Microw. Theory and Tech., Vol. 53, No. 9, 2812-2818, Sep. 2005.
doi:10.1109/TMTT.2005.854177 Google Scholar

12. Velidi, V. K. and A. B. Guntupalli, "Sharp-rejection ultra-wide bandstop filters," IEEE Microw. Wireless Compon. Lett., Vol. 19, No. 8, 503-505, Aug. 2009.
doi:10.1109/LMWC.2009.2024834 Google Scholar

13. Schiffman, B. and G. Matthaei, "Exact design of band-stop microwave filters," IEEE Trans. on Microw. Theory and Tech., Vol. 12, No. 1, 6-15, Jan. 1964.
doi:10.1109/TMTT.1964.1125744 Google Scholar

14. Horton, M. and R. Menzel, "General theory and design of optimum quarter wave TEM filters," IEEE Trans. on Microw. Theory and Tech., Vol. 13, No. 5, 316-327, May 1965.
doi:10.1109/TMTT.1965.1125996 Google Scholar

15. Mandal, M. K. and S. Sanyal, "Compact bandstop filter using signal interference technique," Electron. Lett., 110-111, Jan. 2007.
doi:10.1049/el:20072547 Google Scholar

16. Divyabramham, K., M. K. Mandal, and S. Sanyal, "Sharp-rejection wideband bandstop filters," IEEE Microw. Wireless Compon. Lett., Vol. 18, No. 10, 662-664, Oct. 2008.
doi:10.1109/LMWC.2008.2003452 Google Scholar

17. Mandal, M. K., K. Divyabramham, and V. K. Velidi, "Compact wideband bandstop filter with five transmission zeros," IEEE Microw. Wireless Compon. Lett., Vol. 22, No. 1, 4-6, Jan. 2012.
doi:10.1109/LMWC.2011.2173928 Google Scholar

18. Mandal, M. K., K. Divyabramham, and S. Sanyal, "Compact, wideband bandstop filters with sharp rejection characteristic," IEEE Microw. Wireless Compon. Lett., Vol. 18, No. 10, 665-667, Oct. 2008.
doi:10.1109/LMWC.2008.2003454 Google Scholar

19. Cui, D., Y. Liu, Y. Wu, S. Li, and C. Yu, "A compact bandstop filter based on two meandered parallel-coupled lines," Progress In Electromagnetics Research, Vol. 121, 271-279, 2011.
doi:10.2528/PIER11061902 Google Scholar

20. Wu, Y. and Y. Liu, "A coupled-line band-stop filter with three-section transmission-line stubs and wide upper pass-band performance," Progress In Electromagnetics Research, Vol. 119, 407-421, 2011.
doi:10.2528/PIER11072003 Google Scholar

21. Hsieh, M.-Y. and S.-M. Wang, "Compact and wideband microstrip bandstop filter," IEEE Microw. Wireless Compon. Lett., Vol. 15, No. 7, 472-474, Jul. 2005.
doi:10.1109/LMWC.2005.851572 Google Scholar

Dr. Liming Liang

Dr. Yuan'an Liu

Dr. Jiuchao Li

Dr. Shulan Li

Dr. Cuiping Yu

Prof. Yongle Wu

Dr. Ming Su