Koch-like fractal curve and Sierpinski Gasket are syncretized in minor-main way, forming so called Koch-like sided Sierpinski Gasket multifractal dipole (KSSG). Some iterative combinatorial cases of the two monofractals KiSj KSSG have been investigated in free space without feedline for revealing the assumed multifractal property. Then a pragmatical coplanar stripline (CPS) fed K4S1 KSSG multifractal bow-tie dipole with dimension of 61.1mm×34.75mm was designed, fabricated and measured. Six matched bands(S11<-10dB) with moderate gain (2dBi-6dBi) and high efficiency (80%-95%) are obtained within band 1.5GHz-14GHz, of which f1=2.137GHz (1.978-2.287GHz, 309MHz, 14.46%, PCS1900+IMT2000+UMTS), f2=4.103GHz (3.916-4.2GHz, 374MHz, 9.12%, WiMAX), f3=5.596GHz (5.499-5.679GHz, 180MHz, 3.22%, WLAN+WiMAX) are commonly used. Gain patterns of these bands are all almost omnidirectional in H-plane (Phi=0o, XOZ) and doughnut-shaped in E-plane (Phi=90o, YOZ), which suggests that K4S1 KSSG operates as a half-wavelength dipole. It behaviors like the main fractal in low frequency and resembles the minor one in high frequency. The consistent results of simulation and measurement have evinced the multifractal antennas' peculiar properties and superiority over its monofractals in impedance uniformity, gain pattern, efficiency and dimension. So it is attractive to PCS, UMTS, WLAN, WiFi, WiMAX and other communication systems.
1. Cohen, N., "Fractal antennas: Part 1," Communications Quarterly, 7-22, Aug. 1995.
2. Cohen, N., "Fractal antenna applications in wireless telecommunications," IEEE Electronics Industries Forum of New England, 43-49, 1997.
3. Werner, D. H., R. L. Haup, and P. L. Werner, "Fractal antenna engineering: The theory and design of fractal antenna arrays," IEEE Antennas and Propagation Magazine, Vol. 41, No. 5, 37-58, Oct. 1999. doi:10.1109/74.801513
4. Kaur, J., S. Singh, and A. Kansal, "Multiband behavior of Sierpinski fractal antenna," Res. J. Inform. Technol., Vol. 3, No. 1, 35-43, 2011. doi:10.3923/rjit.2011.35.43
5. Sinha, S. N. and M. Jain, "A self-affine fractal multiband antenna," IEEE Antennas and Wireless Propagation Letters, Vol. 6, 110-112, 2007. doi:10.1109/LAWP.2007.891519
6. Rathee, D. and J. Ashraf, "CPW-fed Sierpinski fractal monopole antenna with varying scale factor," International Journal of Electronics Engineering, Vol. 3, No. 1, 77-80, 2011.
7. Anguera, J., C. Puente, C. Borja, and J. Soler, "Fractal-shaped antennas: A review," Wiley Encyclopedia of RF and Microwave Engineering, Vol. 2, 1620-1635, 2005.
8. Ying, L., S. X. Gong, and D. M. Fu, "The advances in development of fractal antennas," Chinese Journal of Radio Science, Vol. 17, No. 1, Feb. 2002.
9. Mandelbrot, B. B., The Fractal Geometry of Nature, 2nd Ed., W. H. Freeman, New York, 1983.
10. Falconer, K., "Fractal Geometry: Mathematical Foundations and Applications," John Wiley & Son, Inc., New York, 2003.
11. Khan, S. N., J. Hu, J. Xiong, and S. He, "Circular fractal monopole antenna for low VSWR UWB applications," Progress In Electromagnetics Research Letters, Vol. 1, 19-25, 2008. doi:10.2528/PIERL07110903
12. Puente, C., J. Romeu, R. Pous, and A. Cardama, "On the behavior of the Sierpinski multiband fractal antenna," IEEE Trans. on Antennas and Propag., Vol. 46, 517-524, Apr. 1998. doi:10.1109/8.664115
13. Rosu, I., Small antennas for high frequencies, http://www.qsl.n-et/va3iul/.
14. Serkan Basat, S., S. Bhattacharya, and L. Yang, "Design of a novel high-e±ciency UHF RFID antenna on flexible LCP substrate with high read-range capability," IEEE Antennas and Propagation Society International Symposium, Vol. 7, No. 9, 1031-1034, Jul. 2006.
15. Heldring, A., E. Ubeda, and J. M. Rius, "Efficient computation of the effect of wire ends in thin wire analysis," IEEE Trans. on Antennas and Propag., Vol. 54, No. 10, 3034-3037, Oct. 2006. doi:10.1109/TAP.2006.882194
16. Hwang, K. C., "A modified Sierpinski fractal antenna for multiband application," IEEE Antennas and Wireless Propagation Letters, Vol. 6, 2007.
17. Aneesh Kumar, S. and T. K. Sreeja, "A modified fractal antenna for multiband applications," IEEE International Conference on Communication, Control and Computing Technologies (ICC-CCT), Vol. 10, 47-51, 2010. doi:10.1109/ICCCCT.2010.5670770
18. Baliarda, C. P., J. Romeu, and A. Cardama, "The koch monopole: A small fractal antenna," IEEE Trans. on Antennas and Propag., Vol. 48, No. 11, 1773-1781, Nov. 2000. doi:10.1109/8.900236
19. Mahatthanajatuphat, C., S. Saleekaw, and P. Akkaraekthalin, "A rhombic patch monopole antenna with modified Minkowski fractal geometry for UMTS, WLAN, and mobile WiMAX application," Progress In Electromagnetics Research, Vol. 89, 57-74, 2009. doi:10.2528/PIER08111907
20. Lizzi, L. and G. Oliveri, "Hybrid design of a fractal-shaped GSM/UMTS antenna," Journal of Electromagnetic Waves and Applications, Vol. 24, No. 5-6, 707-719, 2010. doi:10.1163/156939310791036386
21. Li, C.-M., K. Wang, and C.-K. Chen, "Small Tri-band monopole antenna for WIMAX/WLAN applications," Journal of Electromagnetic Waves and Applications, Vol. 25, No. 8-9, 1297-1307, 2011. doi:10.1163/156939311795762132
22. He, K., R.-X. Wang, Y.-F. Wang, and B.-H. Sun, "Compact Tri-band claw-shaped monopole antenna for WLAN/WIMAX applications," Journal of Electromagnetic Waves and Applications, Vol. 25, No. 5-6, 869-877, 2011. doi:10.1163/156939311794827104