This paper presents a novel design of a circular ring defected ground structure (DGS) antenna for bandwidth enhancement using fuzzy logic approach. The ground plane of the antenna is defected by introducing circular ring sector type of defect beneath the circular ring patch. The position of the defect in the ground plane to attain the highest return loss and corresponding frequency is determined by using Fuzzy Interface System (FIS). The antenna resonates in X-band showing wideband characteristics with improved gain and reduced cross polar radiations. The return loss and analogous frequency obtained from simulated results and fuzzy system are compared and are in good agreement. The return loss and input impedance is measured experimentally and compared with the simulated results. Parameters like impedance bandwidth, VSWR and antenna gain are likewise calculated and discussed. The simulated results for the radiation pattern of the proposed design with polarization (Co-polar and Cross-polar) are also presented. The simulated impedance bandwidth of about 1.33 GHz (1.2 GHz experimentally) in X-band is obtained with a gain of 6.43 dB and also cross-polarized radiations have an isolation of 20 dB.
2. Bahl, J. and P. Bhartia, Microstrip Antennas, Artech House, Dedham, MA, 1980.
3. Gupta, K. C. and A. Benalla Editors, Microstrip Antenna Design, Artech House, Canton, MA, 1988.
4. James, J. R. and P. S. Hall, Handbook of Microstrip Antennas, IEE Electromagnetic Wave Series No. 28, Vols. 1, 2, Peter Peregrinus Ltd., London, 1989.
5. Bhartia, P., K. V. S. Rao, and R. S. Tomar Editors, Millimeter-wave Microstrip and Printed Circuit Antennas, Artech House, Canton, MA, 1991.
6. Pozar, D. M. and D. H. Schaubert eds., Microstrip Antennas: The Analysis and Designof Microstrip Antennas and Arrays, IEEE Press, New York, 1995.
7. Garg, R., P. Bhartia, I. Bahl, and A. Ittipiboon, Microstrip Antenna Design Handbook, Artech House, New York, 2001.
8. Maci, S. and G. BiffiGentilli, "Dual-frequency patch antennas," IEEE Trans. on Antennas and Propagation Mag., Vol. 39, No. 6, 13-20, 1997.
9. Zulkifli, F. Y., E. T. Rahardjo, and D. Hartanto, "Radiation properties enhancement of triangular patch microstrip antenna array using hexagonal defected ground structure," Progress In Electromagnetics Research M, Vol. 5, 101-109, 2008.
10. Sharma, R., A. Kandwal, and S. K. Khah, "A novel multiband DGS antenna with enhanced bandwidth for wireless communication," Mobile & Embedded Technology International Conference 2013, 89-92, 2013.
11. Lim, J. S., S. Y. C. Jeong, D. Ahn, and S. Nam, "A technique reducing the size of microwave amplifiers using spiral-shaped defected ground structure," J. Korea Electromag. Eng., Vol. 14, No. 9, 904-911, Sep. 2003.
12. Kim, C. S., J. S. Park, and D. Ahn, "A novel 1-D periodic defected ground structure for planar circuits," IEEE Microwave Guided Wave Lett., Vol. 10, No. 4, 131-133, Apr. 2000.
13. Lim, P. L. and K. M. Lum, "A novel bandpass filter design using E-shaped resonator and dual square-loop defected ground structure," PIERS Proceedings, 610-614, Kuala Lumpur, Malaysia, Mar. 27-30, 2012.
14. Zulkifli, F. Y., E. T. Rahardjo, and D. Hartanto, "Mutual coupling reduction using dumbbell defected ground structure for multiband microstrip antenna array," Progress In Electromagnetics Research Letters, Vol. 13, 29-40, 2010.
15. Zainud-Deen, S. H., M. E. S. Badr, E. Hassan, K. H. Awadalla, and H. A. Sharshar, "Microstrip antenna with defected ground plane structure as sensor for landmines detection," Progress In Electromagnetics Research B, Vol. 4, 27-39, 2008.
16. Lim, J. S., K. S. Kim, Y. T. Lee, D. Ahn, and S. Nam, "A spiral shaped defect ground structure for coplanar waveguide," IEEE Microwave and Wireless Components Letters, Vol. 12, No. 9, 330-332, 2009.
17. Weng, L. H., Y.-C. Guo, X.-W. Shi, and X.-Q. Chen, "An overview on defected ground structure," Progress In Electromagnetics Research B, Vol. 7, 173-189, 2008.
18. Hosseini, S. A., Z. Atlasbaf, and K. Forooraghi, "Two new loaded compact planar ultra-wideband antennas using defected ground structures," Progress In Electromagnetics Research B, Vol. 2, 165-176, 2008.
19. Li, L.-X., S.-S. Zhong, and M.-H. Chen, "Compact band-notched ultra-wideband antenna using defected ground structure," Microwave and Optical Technology Letters, Vol. 52, No. 2, 286-289, , 2011.
20. Saad, A. A. R., E. E. M. Khaled, and D. A. Salem, "Wideband slotted planar antenna with defected ground structure," PIERS Proceedings, 1092-1097, Suzhou, China, Sep. 12-16, 2011.
21. Guha, D., M. Biswas, and Y. M. M. Antar, "Microstrip patch antenna with defected ground structure for cross polarization suppression," IEEE Antennas Wireless Propag. Lett., Vol. 4, 455-458, 2008.
22. Kumar, C. and D. Guha, "New defected ground structures (DGSs) to reduce cross-polarized radiation of circular microstrip antennas," IEEE Applied Electromagnetic Conf. AEMC 2009, 1-4, Kolkata, India, 2009, DOI: 10.1109/AEMC.2009.5430671.
23. Guha, D., C. Kumar, and S. Pal, "Improved cross-polarization characteristics of circular microstrip antenna employing arc-shaped defected groundstructure (DGS)," IEEE Antennas Wireless Propag. Lett., Vol. 8, 1367-1369, 2009.
24. Salehi, M. and A. Tavakoli, "A novel low mutual coupling A novel low mutual coupling," Int. J. Electron Commun., Vol. 60, 718-723, 2006.
25. Guha, D., S. Biswas, and C. Kumar, "Annular ring shaped dgs to reduce mutual coupling between two microstrip patches," IEEE Applied Electromagnetic Conf. AEMC 2009, 1-3, Kolkata, India, 2009, DOI: 10.1109/AEMC.2009.5430663.
26. Guha, D., S. Biswas, T. Joseph, and M. T. Sebastian, "Defected ground structure to reduce mutual coupling between cylindrical dielectric resonator antennas," Electronic Lett., Vol. 44, No. 14, 836-837, Jul. 2008.
27. Moghadas, H., A. Tavakoli, and M. Salehi, "Elimination of scan blindness in microstrip scanning array antennas using defected ground structure," Int. J. Electron. Commun., Vol. 62, 155-158, 2008.
28. Ostadzadeh, S. R., M. Soleimani, and M. Tayarani, "A fuzzy model for computing input impedance of two coupled dipole antennas in echelon form," Progress In Electromagnetics Research, Vol. 78, 265-283, 2008.
29. Ostadzadeh, S. R., M. Tayarani, and M. Soleimani, "A fuzzy model for computing back scattering respose from linearly loaded dipole antenna in the frequency domai," Progress In Electromagnetics Research, Vol. 86, 229-242, 2008.
30. Guney, K. and N. Sarikaya, "Comparison of Mamdani and Sugeno fuzzy inference system models for resonant frequency calculation of rectangular microstrip antennas," Progress In Electromagnetics Research B, Vol. 12, 81-104, 2009.
31., , PDF Documents on Fuzzy Logic Toolbox of Matlab 7.10.0 http://www.mathworks.com/.