In this paper, a new compact microstrip low-pass filter (LPF) with ultra-wide stopband characteristics is presented. The combinations of DGS-DMS along with quasi octagonal resonators are employed in the design of the proposed filter to achieve compact size and ultra-wide stopband suppression level. The proposed filter has been designed, simulated, optimized and tested. The design procedure is validated using the commercial full-wave EM MoM simulator Microwave Office. Simulated as well as measured results of low-pass filter exhibit sharp roll-off (ξ) of 19 dB/GHz and creating transmission zero at around 7.8 GHz with attenuation level -54 dB. The measurement results show good agreement with the simulations. The cutoff frequency of the proposed low-pass filter is 2.4 GHz with the insertion loss less than 0.3 dB. The ultra wide stop band with over 20 dB attenuation extended from 3.42 GHz to 12 GHz. The spurious passband suppression up to six harmonics (5fc) is achieved for the proposed design. The addition of two parasitics DGS elements in the ground plane leads to suppression of the undesired harmonics and thus to improve the stopband. The size of the whole structure is less as (0.44λgx0.26λg) with λg = 68 mm. The proposed filter is useful for microwave L band, GPS system, and RADAR applications.
1. Auob, A. and L. Ali, "Compact lowpass filter with wide stop-band using open stubs loaded spiral microstrip resonant cell," Aces Journal, Vol. 16, 27-34, Jan. 2013.
2. Li, L. and Z.-F. Li, "Compact quasi-elliptic low pass filter using symmetric rectangular coupled capacitors," Electron. Lett., Vol. 44, No. 2, 124-125, Jan. 2008. doi:10.1049/el:20082877
3. He, Q. and C. Liu, "A novel low-pass filter with an embedded band-stop structure for improved stopband characteristics," IEEE Microw. Wireless Compon. Lett., Vol. 19, No. 10, 629-631, Oct. 2009.
4. Raphika, P. M., P. Abdulla, and P. M. Jasmine, "Compact low pass filter with a sharp roll-off using patch resonators," Microwave and Optical Technology Letters, Vol. 56, No. 11, 2534-2536, 2014. doi:10.1002/mop.28644
5. Velidi, V. and S. Sanyal, "Sharp roll-off low pass filter with wide stopband using stub-loaded coupled line hairpin unit," IEEE Microw. Wireless Compon. Lett., Vol. 21, No. 6, 301-303, 2011. doi:10.1109/LMWC.2011.2132120
6. Chen, X., L. Zhang, Y. Peng, Y. Leng, H. Lu, and Z. Zheng, "Compact lowpass filter with wide stop band bandwidth," Microwave and Optical Technology Letters, Vol. 57, No. 2, 367-371, 2015. doi:10.1002/mop.28853
7. Packiaraj, D., K. J. Vinoy, M. Ramesh, and A. T. Kalghatgi, "Design of compact low pass filter with wide stop band using tri-section stepped impedance resonator," Int. J. Electron. Commun. (AEÜ), Vol. 65, 1012-1014, 2011. doi:10.1016/j.aeue.2011.03.018
8. Wang, L., H.-C. Yang, and Y. Li, "Design of compact microstrip low-pass filter with ultra-wide stopband using SIRs," Progress In Electromagnetics Research Letters, Vol. 18, 179-186, 2010. doi:10.2528/PIERL10091201
9. Cao, H., W. Guan, S. He, and L. Yang, "Compact lowpass filter with high selectivity using G-shaped defected microstrip structure," Progress In Electromagnetics Research Letters, Vol. 33, 55-62, 2012. doi:10.2528/PIERL12051412
10. Boutejdar, A., A. Elsherbini, and A. S. Omar, "A compact microstrip multi-layer lowpass filter using triangle slots etched in the ground plane," 36th European Microwave Conference, 2006, 271-274, 2006. doi:10.1109/EUMC.2006.281290
11. Balalem, A., A. R. Ali, J. Machac, and A. Omar, "Quasi-elliptic microstrip low-pass filters using an interdigital DGS slot," IEEE Microw. Wireless Compon. Lett., Vol. 17, No. 8, 586-588, Aug. 2007. doi:10.1109/LMWC.2007.901769
12. Chen, X.-Q., R. Li, S.-J. Shi, Q. Wang, L. Xu, and X.-W. Shi, "A novel low pass filter using elliptic shape defected ground structure," Progress In Electromagnetics Research B, Vol. 9, 117-126, 2008. doi:10.2528/PIERB08071801
13. Hayati, M. and A. Lotfi, "Elliptic function low pass filter with sharp cutoff frequency using slit loaded tapered compact microstrip resonator cell," IET Electronics Letters, Vol. 46, No. 2, 143-144, 2010. doi:10.1049/el.2010.3136
14. Boutejdar, A. and W. A. E. Ali, "Improvement of compactness of low pass filter using new Quasi-Yagi-DGS-resonator and multilayer-technique," Progress In Electromagnetics Research C, Vol. 69, 115-124, 2016. doi:10.2528/PIERC16073003
15. Boutejdar, A., A. A. Ibrahim, and E. P. Burte, "Design of a novel ultra wide stop band low pass filter using a DMS-DGS technique for radar applications," International Journal of Microwave Science and Technology, 1-7, 2015. doi:10.1155/2015/101602
16. Boutejdar, A., M. Makkey, A. Elsherbini, and A. Omar, "Design of compact stop band extended microstrip low pass filters by employing mutual coupled square-shaped defected ground structures," Microwave and Optical Technology Letters, Vol. 50, 1107-1111, 2008. doi:10.1002/mop.23273
17. Boutejdar, A., A. Ramadan, M. Makkey, and A. S. Omar, "Design of compact microstrip low pass filters using a U-shaped defected ground structure and compensated microstrip line," Proceedings of the 36th European Microwave Conference, 267-270, Manchester, UK, Sep. 2006.
18. Boutejdar, A., A. Elsherbini, and A. S. Omar, "Method for widening the reject-band in low-pass/band-pass filters by employing coupled C-shaped defected ground structure," IET Microw. Antennas Propag., Vol. 2, No. 8, 759-765, 2008. doi:10.1049/iet-map:20070270
19. Mohra, A. S. S., "Compact lowpass filter with sharp transition band based on defected ground structures," Progress In Electromagnetics Research Letters, Vol. 8, 83-92, 2009. doi:10.2528/PIERL09041406
20. Boutejdar, A., "Design of compact reconfigurable broadband band-stop filter based on a low-pass filter using half circle DGS resonator and multi-layer technique," Progress In Electromagnetics Research C, Vol. 71, 91-100, 2017. doi:10.2528/PIERC16102307
21. Boutejdar, A., et al., "Design of a novel ultrawide stopband lowpass filter using a DMS-DGS technique for radar applications," International Journal of Microwave Science and Technology, Vol. 6, 1-7, 2015. doi:10.1155/2015/101602
22. Challal, M., A. Boutejdar, M. Dehmas, A. Azrar, and A. Omar, "Compact microstrip low-pass filter design with ultra-wide reject band using a novel quarter-circle DGS shape," Appl. Comp. Electro. Society (ACES) Journal, Vol. 27, No. 10, 808-815, Oct. 2012.
23. Boutejdar, A., A. Omar, and E. Burte, "LPF builds on Quasi-Yagi DGS," Microwaves & RF, Vol. 52, 72-77, 2013.
24. Ting, S. W., K. W. Tam, and R. P. Martins, "Miniaturized microstrip low pass filter with wide stop-band using double equilateral U-shaped defected ground structure," IEEE Microw. Wireless Compon. Lett., Vol. 16, 240-242, May 2006. doi:10.1109/LMWC.2006.873592
25. Boutejdar, A., "Design of a very compact U-HI-LO low-pass filter using meander technique and quasi horn inductors for L-band and C-band applications," Microwave and Optical Technology Letters, Vol. 58, No. 12, 2897-290, 2016. doi:10.1002/mop.30173
26. Peng, L., et al., "A low-pass filter with sharp transition and wide stop-band designed based on new metamaterial transmission line," Applied Computational Electromagnetics Society Journal, Vol. 31, No. 10, 1250-1256, 2016.