volume | PIER Journals

Abstract

A novel class of dual-mode filters with improved high frequency sideband suppression response making use of coplanar waveguide (CPW) square loop resonator is presented. The resonator is placed on the bottom plane and inside the defected area of the ground. The resonant property of the CPW square loop resonator as well as the coupling property between two degenerate modes with different patch perturbation is studied in the paper. Two T-shaped orthogonal feed lines are arranged on the top plane, which not only provide proper excitation to the resonator, but also introduce an additional source-load coupling, so the proposed filter is found to have two transmission zeros at high frequency sideband and takes on asymmetric frequency response. Such a compact dual-mode CPW square loop resonator filter operating at 2.68 GHz is designed and fabricated.

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

2. Li, Y. J., Y. Liu, L. Y. Feng, X. Y. Liu, and D. Cheng, "Design of multi-band bandpass filters using short-circuited stub meander loop resonator," 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT), 2018. Google Scholar

3. Gorur, A., "Description of coupling between degenerate modes of a dual-mode microstrip loop resonator using a novel perturbation arrangement and its dual-mode bandpass filter applications," IEEE Transactions on Microwave Theory and Techniques, Vol. 52, No. 2, 671-677, 2004.
doi:10.1109/TMTT.2003.822033 Google Scholar

4. Ieu, W., D. Zhou, D. Zhang, and D. Lv, "Compact dual-mode dual-band HMSIW bandpass filters using source-load coupling with multiple transmission zeros," Electronics Letters, Vol. 55, No. 4, 210-212, 2019.
doi:10.1049/el.2018.7694 Google Scholar

5. Liu, H., B. Ren, S. Hu, X. Guan, and P. Wen, "High-order dual-band superconducting bandpass filter with controllable bandwidths and multitransmission zeros," IEEE Transactions on Microwave Theory and Techniques, Vol. 65, No. 10, 3813-3823, 2017.
doi:10.1109/TMTT.2017.2690295 Google Scholar

6. Cassinese, A., M. Barra, and W. Ciccognani, "Miniaturized superconducting filter realized by using dual-mode and stepped resonators," IEEE Transactions on Microwave Theory and Techniques, Vol. 52, No. 1, 650-654, 2004.
doi:10.1109/TMTT.2003.821250 Google Scholar

7. Deng, J.-Y., M.-J. Li, D. Sun, L.-X. Guo, and X.-H. Ma, "Compact dual-band inverted-microstrip ridge gap waveguide bandpass filter," IEEE Transactions on Microwave Theory and Techniques, Vol. 52, No. 1, 650-654, 2020. Google Scholar

8. Altaf, A., C. Xi, W. Shahzad, U. Dilshad, and J. Miao, "Design of millimeter-wave microstrip BPF using dual-mode ring resonator and folded half-wavelength resonators," 2020 17th IBCAST, 2020. Google Scholar

9. Iqbal, A., J. J. Tiang, and C. K. Lee, "Dual-band half mode substrate integrated waveguide filter with independently tunable bands," IEEE Transactions on Circuits and Systems, Vol. 67, No. 2, 285-289, 2020. Google Scholar

10. Ma, P., B. Wei, J. Hong, B. Cao, X. Guo, and L. Jiang, "Design of dual-mode dual-band superconducting filters," IEEE Transactions on Applied Superconductivity, Vol. 27, No. 17, 1724-1732, 2017. Google Scholar

11. Cheng, Y., C. Mei, and L. Zhu, "Design of dual-mode band-pass filter with novel perturbation elements," Progress In Electromagnetics Research C, Vol. 96, 59-71, 2019.
doi:10.2528/PIERC19061708 Google Scholar

12. Nosrati, A., M. Mohammad-Taheri, and M. Nosrati, "Gap-coupled dual-band evanescent-mode substrate integrated band-pass filter waveguide," Progress In Electromagnetics Research Letters, Vol. 89, 53-59, 2020.
doi:10.2528/PIERL19101302 Google Scholar

Dr. Yuanbao Chen

Dr. Shuang Huang

Dr. Gang Xie

Dr. Jia Chen