volume | PIER Journals

Abstract

A new dual-mode microstrip bandpass filter with wide stop-band is presented using the square loop resonator with treeshaped patches attached to the four inner corners of the loop. The mode splitting is realized by introducing a small cut locating at a 45^◦ offset from its two orthogonal modes. It is shown that the dual-mode filter has a wide stop-band including the first spurious resonance frequency. The center frequency can be tuned. Moreover, the proposed filter has a smaller size compared with conventional dualmode bandpass filters at the same central frequency.

1. Prabhu, S., J. Mandeep, and S. Jovanovic, "Microstrip bandpass filter at S band using capacitive coupled resonator," Progress In Electromagnetics Research, Vol. 76, 223-228, 2007.
doi:10.2528/PIER07071205

2. Fan, J.-W., C.-H. Liang, and X.-W. Dai, "Design of cross-coupled dual-band filter with equal-length split-ring resonators," Progress In Electromagnetics Research, Vol. 75, 285-293, 2007.
doi:10.2528/PIER07060904

3. Wang, J.-P., B.-Z. Wang, and W. Shao, "A novel partly shielded finite ground CPW low pass filter," J. of Electrom. Waves and Appl., Vol. 19, No. 5, 689-696, 2005.
doi:10.1163/1569393053305053

4. Wu, B., B. Li, T. Su, and C.-H. Liang, "Equivalent-circuit analysis and lowpass filter design of split-ring resonator DGS," J. of Electrom. Waves and Appl., Vol. 20, No. 14, 1943-1953, 2006.
doi:10.1163/156939306779322765

5. Xiao, J.-K. and Y. Li, "Novel compact microstrip square ring bandpass filters," J. of Electrom. Waves and Appl., Vol. 20, No. 14, 1943-1953, 2006.
doi:10.1163/156939306779322765

6. Wolff, I., "Microstrip bandpass filter using degenerate modes of a microstrip ring resonator," IEEE Electronics Letters, Vol. 8, No. 12, 302-303, 1972.
doi:10.1049/el:19720223

7. Hong, J.-S. and M. J. Lancaster, "Bandpass characteristics of new dual-mode microstrip square loop resonators," Electronics Letters, Vol. 31, No. 11, 891-892, 1995.
doi:10.1049/el:19950591

8. Tu, W.-H. and K. Chang, "Miniaturized dual-mode bandpass filter with harmonic control," IEEE Microwave and Wireless Components Letters, Vol. 15, No. 12, 838-840, 2005.
doi:10.1109/LMWC.2005.860019

9. Hong, J.-S. and M. J. Lancaster, "Microstrip bandpass filter using degenerate modes of a novel meander loop resonator," IEEE Microwave and Guide Wave Letters, Vol. 5, No. 11, 371-372, 1995.
doi:10.1109/75.473539

10. Zhu, L. and K. Wu, "A joint field/circuit model of line-to-ring coupling structures and its application to the design of microstrip dual-mode filters and ring resonator circuits," IEEE Transactions on Microwave Theory and Techniques, Vol. 47, No. 10, 1938-1948, 1999.
doi:10.1109/22.795068

11. Görur, A., "A novel dual-mode bandpass filter with wide stopband using the properties of microstrip open-loop resonator," IEEE Microwave and Wireless Components Letters, Vol. 12, No. 10, 386-388, 2002.
doi:10.1109/LMWC.2002.804560

12. Görur, A., C. Karpuz, and M. Akpinar, "A reduced-size dualmode bandpass filter with capacitively loaded open-loop arms," IEEE Microwave and Wireless Components Letters, Vol. 13, No. 9, 385-387, 2003.
doi:10.1109/LMWC.2003.817136

13. Fok, S.-W., P. Cheong, K.-W. Tam, and R. P. Martins, "A novel microstrip square-loop dual-mode bandpassfilter with simultaneous size reduction and spurious response suppression," IEEE Transactions on Microwave Theory and Techniques, Vol. 54, No. 5, 2033-2040, 2006.
doi:10.1109/TMTT.2006.873626

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

Professor Yun Xiu Wang

Professor Bing-Zhong Wang

Dr. Jian Wang