An ultra-wideband hexagonal ring antenna with dual tunable band-notches is presented in this paper. The proposed antenna achieves a good impedance match (VSWR≤2) covering the range of 2.5-10.6 GHz, except for the bandwidths of 3.1-3.8 GHz for WiMAX and 5.15-6 GHz for WLAN. The band-notch function is evolved by a stub and two pairs of parasitic elements for WiMAX and WLAN, respectively. The experimental results show that the band-notched characteristics can be tuned by adjusting the lengths of the stub and the two pairs of parasitic elements.
2. Chu, Q.-X. and Y.-Y. Yang, "3.5/5.5 GHz dual band-notch ultra-wideband antenna," Electro. Lett., Vol. 44, No. 3, January 2008.
3. Dong, Y. D., W. Hong, Z. Q. Kuai, and J. Y. Zhou, "Band-notched ultra-wideband antenna designed and optimized by current distribution analysis," International Conference on Microwave and Millimeter Wave Technology, Vol. 3, 1062-1065, April 2008.
4. Yin, K. and J. Xu, "Compact ultra-wideband monopole antenna with band-stop characteristic," International Conference on Microwave and Millimeter Wave Technology, Vol. 3, 1174-1176, April 2008.
5. Wong, K.-L., Y.-W. Chi, C.-M. Su, and F.-S. Chang, "Band-notched ultra-wideband circular-disk monopole antenna with an Arc-shaped slot," Microw. Opt. Technol. Lett., Vol. 45, No. 3, 188-191, May 2005.
6. Kim, Y. and D.-H. Kwon, "CPW-fed planar ultra wideband antenna having a frequency band notch function," Electro. Lett., Vol. 40, No. 7, April 2004.
7. Ding, Y., G.-M. Wang, and J.-G. Liang, "Compact band-notched ultra-wideband printed antenna," Microw. Opt. Technol. Lett., Vol. 49, No. 11, 2686-2689, November 2007.
8. Zhang, L.-N., S.-S. Zhong, X.-L. Liang, and C.-Z. Du, "Compact omni-directional band-notch ultra-wideband antenna," Electro. Lett., Vol. 45, No. 13, June 2009.
9. Dong, Y. D., et al., "Development of ultra-wideband antenna with multiple band-notched characteristics using half mode substrate integrated waveguide cavity technology," IEEE Trans. Antennas Propag., Vol. 56, No. 9, 2894-2902, September 2008.
10. Gao, Y., B.-L. Ooi, and A. P. Popov, "Band-notched ultra-wideband ring-monopole antenna," Microw. Opt. Technol. Lett., Vol. 48, No. 1, 125-126.
11. Abbosh, A. M. and M. E. Bialkowski, "Design of UWB planar band-notched antenna using parasitic elements," IEEE Trans. Antennas Propag., Vol. 57, No. 3, March 2009.
12. Bialkowski, M. E. and A. M. Abbosh, "Design of UWB planar antenna with improved cut-off at the out-of-band frequencies," IEEE Antennas and Wireless Propagation Letters, Vol. 7, 408-410, 2008.
13. Liang, C.-H., Y.-J. Xie, and B.-R. Guan, Microwave Theory, 172, Higher Education Publishing Press, Beijing, China, 2006.
14. Dong, Y. D., W. Hong, Z. Q. Kuai, and J. X. Chen, "Analysis of planar ultra-wideband antennas with on-ground slot band-notched structures," IEEE Trans. Antennas Propag., Vol. 57, No. 7, 1886-1893, July 2009.