This paper aims to present a highly selective, compact size new ultra-wideband (UWB) bandpass filter with three sharp notches for UWB indoor applications. The fundamental geometry of the filter is based on modified multi-mode resonator (MMR) structure which comprises a open-ended step impedance resonator (SIR) attached to an interdigitated uniform impedance resonator (UIR). Realizing a Comb-shaped resonator structure below the UIR and symmetrically extending the lower arm edge of the interdigital coupled lines, three notches are generated at 6 GHz, 6.53 GHz, and 8.35 GHz. These notches have improved the UWB bandpass filter responses by suppressing the existing interferences in the UWB passband created by Wi-Fi 6E (6 GHz), super-extended C band (6.425 GHz~6.725 GHz), X band satellite communications for satellite TV networks or raw satellite feeds (7.25 GHz~8.395 GHz). Concurrently the notched band filter has achieved superiority in other salient features concerning passband and stop band of the filter such as a high passband fractional bandwidth (115.76%), low return loss (-13.27 dB), low insertion loss (0.44 dB~0.97 dB), wide upper stop band (5.37 GHz), nearly flat group delay (0.28 ns~0.45 ns) etc. The ultimate design of UWB bandpass filter is fabricated and verified by comparing the simulated filter responses with the measured results indicating a good agreement.
2. Zhu, L., S. Sun, and W. Menzel, "Ultra-wideband (UWB) bandpass filters using multiple-mode resonator," IEEE Microw. Wireless Compon. Lett., Vol. 15, No. 11, 796-798, Nov. 2005.
3. Jiang, Y., W. Tang, Y. Shi, P. Zhou, and L. Feng, "Compact and low insertion loss UWB on-chip bandpass filter using coupled meanderedline," Microw. Opt. Technol. Lett., 1-7, 2020.
4. Zeng, J., X. Li, and Z. Qi, "UWB bandpass filter with compact size and wide upper stopband," Microw. Opt. Technol. Lett., 1-5, 2019.
5. Kuo, T. N., S. C. Lin, and C. H. Chen, "Compact ultra-wideband bandpass filter using composite microstrip-coplanar-waveguide structure," IEEE Trans. Microwave Theory Tech., Vol. 54, 3772-3778, Oct. 2006.
6. Shaman, H. and J.-S. Hong, "Asymmetric parallel-coupled lines for notch implementation in UWB filters," IEEE Microw. Wireless Compon. Lett., Vol. 17, No. 7, 516-518, Jul. 2007.
7. Chu, Q. X. and X. K. Tian, "Design of UWB bandpass filter using stepped-impedance stub-loaded resonator," IEEE Microw. Wireless Compon. Lett., Vol. 20, No. 9, 501-503, Sep. 2010.
8. Chakraborty, P., P. P. Shome, A. Deb, A. Neogi, and J. R. Panda, "Compact configuration of open ended stub loaded multi-mode resonator based UWB bandpass filter with high selectivity," IEEE 8th International Conference on Signal Processing and Integrated Networks (SPIN), 2021.
9. Shome, P. P., T. Khan, S. K. Koul, and Y. M. M. Antar, "Two decades of UWB filter technology: From elementary designs-to-recent developments," IEEE Microwave Magazine, Vol. 22, No. 8, 1-20, Aug. 2021.
10. Shome, P. P. and T. Khan, "A compact design of circular-ring shaped MMR based bandpass filter for UWB applications," Proc. of the 2019 IEEE Asia-Pacific Microwave Conference (APMC), Singapore, Dec. 2019.
11. Gomez-Garcia and J. I. Alonso, "Systematic method for the exact synthesis of ultra-wideband filtering responses using high-pass and low-pass sections," IEEE Trans. Microwave Theory Tech., Vol. 54, No. 10, 3751-3764, Oct. 2006.
12. Song, Y., G. M. Yang, and W. Geyi, "Compact UWB bandpass filter with dual notched bands using defected ground structures," IEEE Microw. Wireless Compon. Lett., Vol. 24, No. 4, 230-232, Apr. 2014.
13. Sarkar, D., T. Moyra, and L. Murmu, "An ultra-wideband (UWB) bandpass filter with complementary split ring resonator for coupling improvement," International Journal of Electronics and Communication (AEU), Vol. 71, 89-95, 2017.
14. Abbosh, A. M., "Planar bandpass filters for ultra-wideband applications," IEEE Trans. Microwave Theory Tech., Vol. 55, 2262-2269, Oct. 2007.
15. Ghatak, R., P. Sarkar, R. K. Mishra, and D. R. Poddar, "A compact UWB bandpass filter with embedded SIR as band notch structure," IEEE Microw. Wireless Compon. Lett., Vol. 21, No. 5, 261-263, May 2011.
16. Janapala, D. K. and M. Nesasudha, "A compact ultra wide band bandpass filter with dual band notch designed based on composite right/left-handed transmission line unit cell," Int. J. RF Microw. Comput. Aided Eng., 2018.
17. Hsiao, P. Y. and R. M. Weng, "A compact ultra-wideband bandpass filter with WLAN notch band," Microw. Opt. Technol. Lett., Vol. 51, No. 2, 503-507, Feb. 2009.
18. Kumari, P., P. Sarkar, and R. Ghatak, "A multi-stub loaded compact UWB BPF with a broad notch band and extended stopband characteristics," Int. J. RF Microw. Comput. Aided Eng., 2020.
19. Ghazali, A. N., M. Sazid, and S. Pal, "A miniaturized low-cost microstrip-to-coplanar waveguide transition-based ultra-wideband bandpass filter with multiple transmission zeros," Microw. Opt. Technol. Lett., 1-6, 2020.
20. Ghazali, A. N., M. Sazid, and S. Pal, "Multiple passband transmission zeros embedded compact UWB filter based on microstrip/CPW transition," International Journal of Electronics and Communication (AEU), Vol. 129, 1-6, 2021.
21. Sangam, R. S. and R. S. Kshetrimayum, "Notched UWB filter using exponential tapered impedance line stub loaded microstrip resonator," J. Eng., Vol. 2018, No. 9, 768-772, 2018.
22. Wang, C., X. Xi, Y. Zhao, and X. Shi, "Compact tri-notched wideband bandpass filter based on multiple resonances with wide upper stopband," Microw. Opt. Technol. Lett., 1-6, 2020.
23. Makimoto, M. and S. Yamashita, Microwave Resonators and Filters for Wireless Communication Theory, Design and Application, Vol. 4, Springer Series in Advanced Microelectronics, 2001.
24. Zhu, L., S. Sun, and R. Li, Microwave Bandpass Filters for Wideband Communications, John Wiley & Sons, Inc., 2012.
25. Ansoft Corporation, Ansoft HFSS (Version 11), 2007.
26. Basit, A., M. I. Khattak, and M. Alhasan, "Design and analysis of a microstrip planar UWB bandpass filter with triple notch bands for WiMAX, WLAN, and X-band satellite communication systems," Progress In Electromagnetics Research M, Vol. 93, 155-164, 2020.
27. Liu, F. and M. Qun, "A new compact UWB bandpass filter with quad notched characteristics," Progress In Electromagnetics Research Letters, Vol. 88, 83-88, 2020.
28. Weng, M. H., C. W. Hsu, S. W. Lan, and R. Y. Yang, "An ultra-wideband bandpass filter with a notch band and wide upper bandstop performances," Electronics, Vol. 8, 1316, 2019.
29. Sazid, M. and N. S. Raghava, "Planar UWB-bandpass filter with multiple passband transmission zeros," International Journal of Electronics and Communication (AEU), Vol. 134, 1-7, 2021.