volume | PIER Journals

Abstract

This paper presents a new compact dual-band bandpass filter (BPF) with a stub-loaded resonator structure that can independently change its operating band to support GSM and WiFi applications for modern wireless communications. A short-circuit stub with a metal through hole is placed into the symmetrical resonator together with a pair of step impedance stubs and a pair of uniform open-circuit stubs. Inside the resonator, the open stubs fold in on themselves, minimizing the circuit for integration with other parts and enhancing the selectivity of the filter. Even-odd mode theory can be employed to investigate the circuit because of the resonator geometric symmetry. The first and second operational frequency bands can then be built using the calculated odd and even mode frequencies to match our requirements. The manufactured experimental dual-band filter is compared to the simulation results, and the statistics revealed good agreement. The calculated structural measures 0.13λ_g × 0.1λ_g.

1. Karimzadeh-Jazi, R., M. A. Honarvar, and F. Khajeh-Khalili, "High Q-factor narrow-band bandpass filter using cylindrical dielectric resonators for X-band applications," Progress In Electromagnetics Research Letters, Vol. 77, 65-71, 2018.
doi:10.2528/PIERL18041007

2. Kumar, R. and S. N. Singh, "Design and analysis of ridge substrate integrated waveguide bandpass filter with octagonal complementary split ring resonator for suppression of higher order harmonics," Progress In Electromagnetics Research C, Vol. 89, 87-99, 2019.
doi:10.2528/PIERC18080404

3. Gorur, A. K., "A novel compact microstrip balun bandpass filter design using interdigital capacitor loaded open loop resonators," Progress In Electromagnetics Research Letters, Vol. 76, 47-53, 2018.
doi:10.2528/PIERL18010926

4. Wei, F., H. J. Yue, X. H. Zhang, and X.-W. Shi, "A balanced quad-band BPF with independently controllable frequencies and high selectivity," IEEE Access, Vol. 7, 110316-110322, 2019.
doi:10.1109/ACCESS.2019.2934494

5. Yang, Q., Y.-C. Jiao, and Z. Zhang, "Compact multiband bandpass filter using low-pass filter combined with open stub-loaded shorted stub," IEEE Transactions on Microwave Theory and Techniques, Vol. 66, No. 4, 1926-1938, 2018.
doi:10.1109/TMTT.2018.2791961

6. Yin, B. and Z. Y. Lin, "A novel dual-band bandpass SIW filter loaded with modified dual-CSRRs and Z-shaped slot," Int. J. of Electron. Commun., Vol. 121, 153-261, 2020.

7. Wang, Z. J., C. Wang, and N. Y. Kim, "Dual-/triple-wideband microstrip bandpass filter using independent triple-mode stub-loaded resonator," Microwave and Optical Technology Letters, Vol. 60, No. 1, 56-64, 2018.
doi:10.1002/mop.30909

8. Tang, M. C., T. Shi, S. Y. Chen, and H. L. Cao, "Dual-band bandpass filter based on a single triple-mode ring resonator," Electron. Lett., Vol. 52, No. 9, 722-723, 2016.
doi:10.1049/el.2015.2692

9. Huang, W., L. Li, L. Li, Y. Ren, and Y. Ma, "A compact coplanar waveguide dual-band bandpass filters based on defected ground structures," IEICE Electronics Express, Vol. 18, No. 15, 16, 2021.
doi:10.1587/elex.18.20210053

10. Lai, X., C. H. Liang, H. Di, and B. Wu, "Design of tri-band filter based on stub loaded resonator and DGS resonator," IEEE Microwave and Wireless Components Letters, Vol. 20, No. 5, 265-267, 2010.
doi:10.1109/LMWC.2010.2045584

11. Lu, H., Y. Yuan, J. Huang, X. Zhang, and N. Yuan, "Design of compact dual-mode dual-band microstrip bandpass filter using stepped-impedance resonator for wireless communication applications," 2018 International Conference on Microwave and Millimeter Wave Technology, 1-3, 2018.

12. Ren, B., H. Liu, Z. Ma, M. Ohira, P.Wen, X. Wang, and X. Guan, "Compact dual-band differential bandpass filter using quadruple-mode stepped-impedance square ring loaded resonators," IEEE Access, Vol. 6, 21850-21858, 2018.
doi:10.1109/ACCESS.2018.2829025

13. Song, K., F. Zhang, and Y. Fan, "Miniaturized dual-band bandpass filter with good frequency selectivity using SIR and DGS," Int. J. of Electron. Commun., Vol. 68, No. 5, 384-387, 2014.
doi:10.1016/j.aeue.2013.10.005

14. Zobeyri, M. R. and A. R. Eskandari, "Design of single- and dual-band BPFs using folded 0˚ feed structures and embedded resonators," International Journal of Electronics and Communications, Vol. 96, 18-29, 2018.
doi:10.1016/j.aeue.2018.09.011

15. Pozar, D. M., Microwave Engineering, Wiley, 2009.

16. Sami, A. and M. Rahman, "A very compact quintuple band bandpass filter using multimode stub loaded resonator," Progress In Electromagnetics Research C, Vol. 93, 211-222, 2019.
doi:10.2528/PIERC19040409

Dr. Guangyong Wei

Professor Yun Xiu Wang

Dr. Jie Liu

Dr. Hai Ping Li