In this paper, a new flower-shaped microstrip line feed reconfigurable band-notched UWB monopole antenna using single varactor diode is introduced and fabricated. Different notch frequencies can be obtained using different capacitor values. The effect of changing the varactor position is also examined. The flower shape is first optimized to obtain UWB characteristics. Then, a slot is made in the microstrip line to be loaded later with a single varactor diode. A wide range of notch frequencies can be obtained using this simple configuration which cover most of the narrow band coexistence systems. The notch frequency can be lower by increasing the capacitance value. The notch frequency covers the WLAN band when C=0.8 PF and covers the WIMAX band when the capacitance is changed to 0.7 PF for the same antenna configuration and varactor position. Two prototypes of the proposed antenna using two different single capacitor elements with capacitances 0.6 PF and 1.5 PF are fabricated, and their reflection characteristics are measured and compared with the simulated ones. Notch frequencies at 6.1 GHz and 4.3 GHz are obtained respectively in both simulated and measured antenna structures. The proposed antenna a directive radiation pattern in E-plane and omnidirectional pattern in H-plane. Also the gain is suppressed in the notched frequencies. The group delay is nearly stable in the UWB frequency range with very little variations, but it is distorted sharply at the notch frequencies. So, the proposed antenna is a good candidate for the modern UWB systems.
2. Galvan-Tejada, G. M., M. A. Peyrot-Solis, and H. Jardon-Aguilar, Ultra Wideband Antennas: Design Methodologies, and Performance, CRC Press, 2016.
3., , First Report and Order Revision of part 15 of the commission's rule regarding ultra-wideband transmission system FCC 02-48, Federal Communications Commission, 2002.
4. Ullah, S., M. Ali, M. A. Hussain, and K. S. Kwak, "Applications of UWB technology," IET Microw. Antennas Propag., Vol. 8, No. 8, 541-548, 2015.
5. Ryu, K. S. and A. A. Kishk, "UWB antenna with single or dual band-notches for low WLAN band and upper WLAN Band," IEEE Trans. Antennas Propag., Vol. 57, No. 12, 2009.
6. Roozbahani, M. G., A. A. Kalteh, and R. Fallahi, "A novel UWB elliptical slot antenna with band-notch characteristics," Progress In Electromagnetics Research, Vol. 82, 127-136, 2008.
7. Choi, J., J. Jung, K. Chung, and W. Choi, "Compact ultra-wideband printed antenna with bandrejection characteristic," Electron. Lett., Vol. 41, No. 18, 124-126, 2005.
8. Wang, M.-F., J.-X. Xiao, and S.-W. Wang, "Study of a dual-band notched wideband circular slot antenna," Journal of Electromagnetic Waves and Applications, Vol. 24, No. 17–18, 2445-2452, 2010.
9. Zhou, D., S. Gao, F. Zhu, R. A. Abd-Alhameed, and J. D. Xu, "A simple and compact planar ultra wide-band antenna with single or dual band-notched characteristics," Progress In Electromagnetics Research, Vol. 123, 47-65, 2012.
10. Azim, R. and M. T. Islam, "Compact planar UWB antenna with band notch characteristics for WLAN and DSRC," Progress In Electromagnetics Research, Vol. 133, 391-406, 2013.
11. Sun, J.-Q., X.-M. Zhang, Y.-B. Yang, R. Guan, and L. Jin, "Dual band-notched ultra-wideband planar monopole antenna with M- and W-slots," Progress In Electromagnetics Research Letters, Vol. 19, 1-8, 2010.
12. Jang, J. W. and H. Y. Hwang, "An improved band-rejection UWB antenna with resonant patches and a slot," IEEE Trans. Antennas Propag., Vol. 8, 299-302, 2009.
13. Fernandes, C. A., J. R. Costa, and C. R. Medeiros, "Compact tapered slot UWB antenna with WLAN band rejection," IEEE Trans. Antennas Propag., Vol. 8, 661-664, 2009.
14. Lee, J. W., J. Kim, and C. S. Cho, "5.2GHz notched ultra-wideband antenna using slot-type SRR," Electron. Lett., Vol. 42, No. 6, 2006.
15. Li, C. M. and L. H. Ye, "Improved dual band-notched UWB slot antenna with controllable notched band-widths," Progress In Electromagnetics Research, Vol. 115, 477-493, 2011.
16. Bahadori, K. and Y. R. Samii, "A miniaturized elliptic-card UWB antenna with WLAN band rejection for wireless communications," IEEE Trans. Antennas Propag., Vol. 55, No. 11, 3326-3332, 2007.
17. Zhu, F., A. A. Alhameed, and J. Xu, "Multiple band notched UWB antenna with band rejected elements integrated in the feed line," IEEE Trans. Antennas Propag., Vol. 61, No. 8, 3952-3959, 2013.
18. Kim, K. H., S. O. Park, S. H. Hwang, and Y. J. Cho, "Band-notched UWB planar monopole antenna with two parasitic patches," Electron. Lett., Vol. 41, No. 14, 2005.
19. Yang, Y., Y.-Z. Yin, Y.-Q. Wei, B.-W. Liu, and A.-F. Sun, "A circular wide-slot antenna with dual band-notched characteristics for UWB applications," Progress In Electromagnetics Research Letters, Vol. 23, 137-145, 2011.
20. Ruan, C. L. and L. Peng, "UWB band-notched monopole antenna design using electromagneticbandgap structures," IEEE Trans. Antennas Propag., Vol. 59, No. 4, 1074-1081, 2011.
21. Islam, M. T., R. Azim, and A. T. Mobashsher, "Triple band-notched planar UWB antenna using parasitic strips," Progress In Electromagnetics Research, Vol. 129, 161-179, 2012.
22. Fallahi, R., "A novel UWB elliptical slot antenna with band-notched characteristics," Progress In Electromagnetics Research, Vol. 82, 127-136, 2008.
23. Hu, Y.-S., M. Li, G.-P. Gao, J.-S. Zhang, and M.-K. Yang, "A double-printed trapezoidal patch dipole antenna for UWB applications with band-notched characteristic," Progress In Electromagnetics Research, Vol. 103, 259-269, 2010.
24. Zhu, F., S. Gao, A. T. S. Ho, C. H. See, R. A. Abd-Alhameed, J. Li, and J. Xu, "Design and analysis of planar ultra-wideband antenna with dual band-notched function," Progress In Electromagnetics Research, Vol. 127, 523-536, 2012.
25. Liu, W. X. and Y. Z. Yin, "Dual band-notched antenna with the parasitic strip for UWB," Progress In Electromagnetics Research Letters, Vol. 25, 21-30, 2011.
26. Gao, G.-P., Z.-L. Mei, and B.-N. Li, "Novel circular slot UWB antenna with dual band-notched characteristic," Progress In Electromagnetics Research C, Vol. 15, 49-63, 2010.
27. Badamchi, B., J. Nourinia, C. Ghobadiand, and A. V. Shahmirzadi, "Design of compact reconfigurable ultra-wideband slot antenna with switchable single/dual band notch functions," IET Microw. Antennas Propag., Vol. 8, No. 8, 541-548, 2014.
28. Wu, W., Y.-B. Li, R.-Y. Wu, C.-B. Shi, and T.-J. Cui, "Band-notched UWB antenna with switchable and tunable performance," International Journal of Antennas and Propagation, Hindawi Publishing Corporation, 2016.
29. Li, Y. and R. Mittra, "Tunable and reconfigurable frequency rejection circular slot antenna for UWB communication applications," PIERS Proceedings, 1583-1587, Prague, Czech Republic, Jul. 6–9, 2015.
30., , http://www.ansys.com/Products/Electronics/ANSYS-HFSS.
31., , https://www.cst.com/products/cstmws.