A new wideband vertical planar printed unidirectional antenna is presented. The proposed antenna is composed of a bowtie electric dipole, a loop antenna and a microstrip-to-coplanar stripline balun. All of them are printed in the same plane perpendicular to the ground. The antenna has a wide impedance bandwidth of 87.2% for SWR≤2 from 3.3 to 8.4 GHz and a stable gain of 7.3±1.5 dBi over the operating frequencies. Moreover, stable unidirectional radiation pattern with low back-lobe radiation, low cross polarization and nearly identical E- and H-plane patterns is also demonstrated over the frequency of interest. A prototype is fabricated and measured. The measured results indicate that the antenna is suitable for wideband wireless communication system.
2. Ouyang, J., S. Bo, J. Zhang, and F. Yang, "A low-profile unidirectional cavity-backed log-periodic slot antenna," Progress In Electromagnetics Research, Vol. 119, 423-433, 2011.
doi:10.2528/PIER11070503
3. Costa, K. Q., V. Dmitriev, D. C. Nascimento, and J. C. D. S. Lacava, "Broadband L-probe fed patch antenna combined with passive loop elements," IEEE Antennas Wirel. Propag. Lett., Vol. 6, 100-102, 2007.
doi:10.1109/LAWP.2007.893071
4. Lai, H. W. and K. M. Luk, "Design and study of wide-band patch antenna fed by meandering probe," IEEE Trans. Antennas Propag., Vol. 54, No. 2, 564-571, 2006.
doi:10.1109/TAP.2005.863091
5. Costa, K. Q. and V. Dmitriev, "Planar monopole UWB antennas with cuts at the edges and parasitic loops," Ultra Wideband Communications: Novel Trends --- Antennas and Propagation, Vol. 9, 143-145, InTech, 2011.
6. Luk, K. M. and H. Wong, "A new wideband unidirectional antenna element," Int. J. Microw. Opt. Technol., Vol. 1, 35-44, 2006.
7. Siu, L., H.Wong, and K. M. Luk, "A dual-polarized magneto-electric dipole with dielectric loading," IEEE Trans. Antennas Propag., Vol. 57, No. 3, 616-623, 2009.
doi:10.1109/TAP.2009.2013430
8. Costa, K. Q. and V. Dmitriev, "Combination of electric and magnetic dipoles with single-element feeding for broadband applications," Microwave and Optical Technology Letters, Vol. 48, No. 1, 8-12, 2006.
doi:10.1002/mop.21248
9. An, W. X., K. L. Lau, S. F. Li, and Q. Xue, "Wideband E-shaped dipole antenna with staircase-shaped feeding strip," Electron. Lett., Vol. 46, No. 24, 1583-1584, 2010.
doi:10.1049/el.2010.2890
10. Wu, B. Q. and K. M. Luk, "A magneto-electric dipole with a modified ground plane," IEEE Antennas Wirel. Propag. Lett., Vol. 8, 627-629, 2009.
11. Zhang, Z. Y., G. Fu, S. L. Zuo, and X. Gong, "Wideband unidirectional patch antenna with Γ-shaped strip feed," Electron. Lett., Vol. 46, No. 1, 24-26, 2010.
doi:10.1049/el.2010.2825
12. Ge, L. and K. M. Luk, "A wideband magneto-electric dipole antenna," IEEE Trans. Antennas Propag., Vol. 60, No. 11, 4987-4991, 2012.
doi:10.1109/TAP.2012.2207689
13. Chu, Q. X. and Y. Luo, "A broadband unidirectional multi-dipole antenna with very stable beamwidth," IEEE Trans. Antennas Propag., Vol. 61, No. 5, 2847-2852, 2013.
doi:10.1109/TAP.2013.2243898
14. Li, M. J. and K. M. Luk, "A differential-fed magneto-electric dipole antenna for UWB applications," IEEE Trans. Antennas Propag., Vol. 61, No. 1, 92-99, 2013.
doi:10.1109/TAP.2012.2220100
15. Ge, L. and K. M. Luk, "A magneto-electric dipole for unidirectional UWB communications," IEEE Trans. Antennas Propag., Vol. 61, No. 11, 5762-5765, 2013.
doi:10.1109/TAP.2013.2276924
16. Chan, P. W., H. Wong, and E. K. N. Yung, "Unidirectional antenna composed of dipole and loop," Electron. Lett., Vol. 43, No. 22, 2007.
doi:10.1049/el:20071980
17. Tang, C. and Q. Xue, "Vertical planar printed unidirectional antenna," IEEE Antennas Wirel. Propag. Lett., Vol. 12, 368-371, 2013.
doi:10.1109/LAWP.2013.2252321
18. Sun, Y. H., G. J. Wen, H. Y. Jin, P. Wang, and Y. J. Huang, "Gain enhancement for wide bandwidth endfire antenna with I-shaped resonator (ISR) structures," Electron. Lett., Vol. 49, No. 12, 736-737, 2013.
doi:10.1049/el.2013.1198
Submit
