COMPACT TRIPLE-BAND BANDPASS FILTER USING MULTI-MODE RESONATOR (MMR) WITH MULTIPLE TRANSMISSION ZEROS

In this article, a compact triple-band microstrip bandpass filter (BPF) with tunable centre frequencies and bandwidths as well as multiple transmission zeros (TZs) is presented. The proposed filter is designed based on a novel multi-mode resonator (MMR), and the even-/odd-mode analysis method is employed to investigate its resonant characteristics. By changing the lengths of two loaded coupled open stubs and coupling space between them, two resonant modes can be tuned and the bandwidth can be controlled. Also, two additional TZs are generated due to the dual-finger feed structure. Moreover, these two TZs can be controlled by the lengths of two fingers, and high passband selectivity and band-to-band isolation level are achieved with ten TZs. The three centre frequencies of the proposed triple-band BPF are located at 1.9, 3.55, and 7.33 GHz, respectively. In addition, the overall circuit size of the fabricated filter is much smaller in comparison with previous works. For demonstration, a prototype filter is fabricated and measured, and good agreements are obtained between the measured results and electromagnetic (EM) simulated ones

Keywords:

Bandpass filter (BPF), multi-mode resonator (MMR) transmission zeros, triple-band filter,

PDF

___

[1] Zhang Songbai and Lei Zhu, “Compact Split-Type DualBand Bandpass Filter Based on λ/4 Resonators”, IEEE Microw. Wireless Compon. Lett., vol. 23, no. 7, pp. 344- 346, Jul., 2013. [2] Songbai Zhang and Lei Zhu, “Compact Tri-Band Bandpass Filter Based on λ/4 Resonators With U-Folded Coupled-Line”, IEEE Microw. Wireless Compon. Lett., vol. 23, no. 5, pp. 258-260, May, 2013. [3] Jun Li, Shanshan Huang, Hui Wang, Yao Li, and Jianzhong Zhao, “A Novel Compact Tri-Band Bandpass Filter Using SIR Embedded Quarter-Wavelength Resonators”, Microw. Opt. Technl. Leet., vol. 57, no. 6, pp. 1345-1349, June 2015. [4] Q. -X. Chu and X. -M. Lin, “Advanced Triple-Band Bandpass Filter Using Tri-Section SIR”, Electron. Lett., vol. 44, no. 4, pp. 295-296, Feb., 2008. [5] F. -C. Chen and Q. -X. Chu, “Compact Triple-Band Bandpass Filter Using Pseudointerdigital Trisection Stepped Impedance Resonators”, Microw. Opt. Technol. Lett., vol. 50, no. 9, pp. 2462-2465, Sept., 2008. [6] Sun S.-J., Su Tao, Deng Kun, Wu Bian, and Liang C.-H, “Shorted-Ended Stepped-Impedance Dual-Resonance Resonator and Its Application to Bandpass Filters”, IEEE Trans. Microw. Theory Tech., vol. 61, no. 9, pp. 3209-3215, Sept., 2013. [7] Jun Li, Shan Shan Huang, Hui Wang, and Jian Zhong Zhao, “Compact Dual-Band Bandpass Filter Using Embedded Center-Grounded SIR and Open-Loop Resonators”, Progr. Electromagn. Res. Lett., vol. 49, pp. 9-14, Sep., 2014. [8] Jun Li, Shan Shan Huang, and Jian Zhong Zhao, “Design of a Compact and High Selectivity Tri-Band Bandpass Filter Using Asymmetric Stepped-Impedance Resonators (SIRs)”, Progr. Electromagn. Res. Lett., vol. 44, 81-86, Jan., 2014. [9] H-W. Wu and R-Y. Yang, “Design of a Triple-Passband Microstrip Bandpass Filter With Compact Size”, J. Electromagn. Waves Appl., vol. 24, no. 17-18, pp. 2333-2341, 2010. [10] Liu, S-K., and F-Z. Zheng, “A New Compact Tri-Band Bandpass Filter Using Step Impedance Resonators With Open Stubs”, J. Electromagn. Waves Appl., vol. 26, no. 1, pp. 130-139, 2012. [11] Chen Wei-Yu, Min-Hang Weng, and Shoou-Jinn Chang, “A New Tri-Band Bandpass Filter Based on Stub-Loaded StepImpedance Resonator”, IEEE Microw. Wireless Compon. Lett., vol. 22, no. 4, pp. 179-181, Apr., 2012. [12] K. Xu, Y. Zhang, D. Li, Y. Fan, J. L.-W. Li, W. T. Joines, and Q. H. Liu, “Novel Design of a Compact Triple-Band Bandpass Filter Using Short Stub-Loaded SIRs and Embedded SIRs Structure”, Progr. Electromagn. Res., vol. 142, pp. 309-320, 2013. [13] Chen, J-Z., et al, “Fourth-Order Tri-Band Bandpass Filter Using Square Ring Loaded Resonators”, Electron. Lett., vol. 47, no. 15, pp. 858-859, 2011. [14] Doan M. T., W. Q. Che, and W. J. Feng, “Tri-Band Bandpass Filter Using Square Ring Short Stub Loaded Resonators”, Electron. Lett., vol. 48, no. 2, pp. 106-107, 2012. [15] S. J. Sun, L. Lin, B. Wu, K. Deng, and C.-H. Liang, “A Novel Quad-Mode Resonator and Its Application to Dual-Band Bandpass Filters”, Progr. Electromagn. Res. Lett., vol. 43, pp. 95-104, 2013. [16] Xu J., Miao C., Cui L., Ji Y.-X., and Wu W, “Compact High Isolation Quad-Band Bandpass Filter Using QuadMode Resonator”, Electron. Lett., vol. 48, no. 1, pp. 28- 30, 2012. [17] Jun Li, Shan Shan Huang, and Jian Zhong Zhao, “Compact Microstrip Dual-Wideband Bandpass Filter Using a Novel Multi-Mode Resonator”, Open Science Journal of Electrical and Electronic Engineering, to be published, 2014. [18] Gao Li, and Xiu Yin Zhang, “High-Selectivity Dual-Band Bandpass Filter Using a Quad-Mode Resonator With SourceLoad Coupling”, IEEE Microw. Wireless Compon. Lett., vol. 23, no. 9, pp. 474-476, Sept., 2013. [19] Jun Li, Shan-Shan Huang, and Jian-Zhong Zhao, “Compact Dual-Wideband Bandpass Filter Using a Novel Penta-Mode Resonator (PMR)”, IEEE Microw. Wireless Compon. Lett., vol. 24, no. 10, pp. 668-670, Oct., 2014. [20] Gómez-García Roberto, and José 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, pp. 530-532, Aug., 2005.