A novel 1.8 GHz compact microstrip low-pass filter (LPF) based on quasi-yagi defected ground structure (DGS) and compensated capacitors is proposed in this paper. The filter has a very sharp cut-off frequency response with low insertion loss and achieves a wide reject band with overall 20 dB attenuation from 2.8 GHz up to 10 GHz. The equivalent circuit model of Yagi-DGS-unit is derived using AWR software, and the circuit parameters are extracted by using a simple circuit analysis method. The advantage of this structure is that the reject band can be controlled by tuning the dimension of Yagi-arms at higher frequency rang. The proposed 1.8 low-pass filter is designed using microwave office electromagnetic software and fabricated on the RO4003 ceramic structure with dielectric constant of 3.38. The compact filter occupies an area of (0.45λg × 0.35λg) with λg = 44 mm. A comparison between simulation and measurement results confirms the validity of the LPF configuration and design procedure. In order to improve the compactness of the proposed LPF, a new multi-layer method has been employed. Finally, a new minimized LPF-topology 50% more compact than the conventional is realized.
2. Boutejdar, A., N. M. Eltabit, A. A. Ibrahim, and E. P. Burte, "Design of wide stop band Lband LPF based on DMS-DGS-technique for radar applications," Hindawi Publishing Corporation International Journal of Microwave Science and Technology, Vol. 2015, Article ID 101602, 7 pages, 2015.
3. Boutejdar, A., A. Rahman, A. Batmanov, A. Omar, and E. Burte, "Miniaturized band-stop filter based on multilayer-technique and new coupled octagonal DGS with interdigital capacitor," Microw. Opt. Technol. Lett., Vol. 52, No. 3, 510-514, Mar. 2010.
4. Hong, J. S. and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications, Wiley, New York, 2001.
5. Boutejdar, A., A. Batmanov, A. Omar, and E. Burte, "A miniature 3.1GHz microstrip bandpass filter with suppression of spurious harmonics using multilayer technique and defected ground structure open-loop ring," Ultra-wideband, Short-pulse Electromagnetics, 191-200, New York, Springer, ISBN 978-0-387-77844-0, 2010.
6. Abdel-Rahman, A., A. K. Verma, A. Boutejdar, and A. S. Omar, "Compact stub type microstrip bandpass filter using defected ground plane," IEEE Microwave and Wireless Components Letters, Vol. 14, 136-138, 2004.
7. Al Sharkawy, M., A. Boutejdar, F. Alhefnawi, and O. Luxor, "Improvement of compactness of lowpass/bandpass filter using a new electromagnetic coupled crescent defected ground structure (DGS) resonators," ACES Journal — The Applied Computational Electromagnetics, Vol. 25, No. 9, Jul. 2010.
8. Dal, A., J. S. Park, C. S. Kim, J. Kim, Y, and T. Itoh, "A design of the low-pass filter using the novel microstrip defected ground structure," IEEE Trans. Microw. Theory Tech., Vol. 49, 86-93, May 2001.
9. 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, No. 4, 1107-1111, Apr. 2008.
10. Moyra, T., S. K. Parui, and S. Das, "Design of a quasi-elliptic lowpass filter using a new defected ground structure and capacitively loaded microstrip line," International Journal on Electrical Engineering and Informatics, Vol. 3, No. 1, 61-73, Apr. 2011.
11. Boutejdar, A., A. Batmanov, E. Burte, and A. Omar, "Design of a new bandpass filter with sharp transition band using U-defected ground structure (DGS) and multilayer-technique," IET Microwave, Antennas and Propagation, Vol. 4, No. 9, 1415-1420, Sep. 2010.
12. Boutejdar, A., W. Abd Ellatif, A. A. Ibrahim, and M. Challal, "A simple transformation from lowpass to bandpass filter using a new quasi-arrow head defected ground structure resonator and gap-J-inverter," Microwave and Optical Technology Letters, Vol. 58, No. 4, 947-953, Apr. 2016.
13. Tizyi, H., F. Riouch, A. Tribak, A. Najid, and A. Mediavilla Sanchez, "CPW and microstrip linefed compact fractal antenna for UWB-RFID applications," Progress In Electromagnetics Research C, Vol. 65, 201-209, 2016.
14. Boutejdar, A., A. A. Ibrahim, and E. P. Burte, "A compact multiple band-notched planer antenna with enhanced bandwidth using parasitics strip lumped capacitors and DGS-technique," Telkomnika Idonesian Journal of Electrical Engineering, Vol. 13, No. 2, 2015.
15. Han, Y.-L., Y.-C. Jiao, T. Ni, and Z.-B.Weng, "Novel compact dual-band branch-line couplers with half elliptical-ring impedance stub lines," Progress In Electromagnetics Research Letters, Vol. 56, 9-15, 2015.
16. Wang, X., Z. Ma, I. Sakagami, A. Mase, and M. Yoshikawa, "A small wilkinson power divider with complex isolation component," Microwave and Optical Technology Letters, Vol. 58, No. 9, 2163-2168, Sep. 2016.
17. Heungjae, C., Y. Jeong, J. S. Kenney, and C. D. Kim, "Dual-band feedforward linear power amplifier for digital cellular and IMT-2000 basestation," Microwave and Optical Technology Letters, Vol. 51, No. 4, 922-926, Apr. 2009.
18. Mohra, A. S., "Compact lowpass filter with sharp transition band based on defected ground structures," Progress In Electromagnetics Research Letters, Vol. 8, 83-92, 2009.
19. Boutejdar, A., et al., "DGS resonators form compact filters," Microwaves and RF, Mar. 24, 2015.
20. Chen, J., Z.-B. Weng, Y.-C. Jiao, and F.-S. Zhang, "Lowpass filter design of hilbert curve ring defected ground structure," Progress In Electromagnetics Research, Vol. 70, 269-280, 2007.
21. Boutejdar, A., A. Omar, and E. Burte, "Miniaturized lowpass and bandstop filters using controlled coupling of open-loop-ring defected ground structure (DGS)," Microwave and Optical Technology Letters, Vol. 52, No. 11, 2575-2578, Nov. 25, 2010.
22. Challal, M., A. Boutejdar, A. Dehmas, M. Azrar, and A. Omar, "Compact microstrip low-pass filter design with ultra-wide reject band using a novel quarter-circle DGS shape," Aces Journal, Vol. 27, No. 10, 808-815, Oct. 2012.
23. Ting, S. W., K. W. Tam, and R. P. Martins, "Miniaturized microstrip lowpass filter with wide stop-band using double equilateral U-shaped defected ground structure," IEEE Microwave Wireless Compon Lett., Vol. 16, 240-242, May 2006.
24. Hsiao, P. Y. and R. M. Weng, "An ultra-wide stop-band low-pass filter using dual reverse U-shaped DGS," Microwave and Optical Technology Letters, Vol. 50, No. 11, 2783-2780, Nov. 2008.
25. Boutejdar, A., et al., "Compensating for DGS filter loss," Microwave & RF Journal, 23-28, Feb. 16, 2012.