volume | PIER Journals

Abstract

A novel omnidirectional circularly polarized (CP) antenna with single feed is proposed for 2.4 GHz WLAN applications. Based on the zeroth-order resonance (ZOR) mode of epsilon negative (ENG) transmission line (TL), the antenna excites uniform vertically polarized E-field just as the monopole does. A modified Alford loop with electromagnetic coupling fed by L-shaped strip consists of four curved branches, which is placed on the top of the antenna and generates an equivalent horizontally polarized magnetic dipole mode. Once the two orthogonally polarized components are equal in amplitude but different in phase by 90˚, omnidirectional CP wave can be obtained. The measured results show that the impedance bandwidth (S₁₁<-10 dB) is 6% (2.38-2.53 GHz), and the 3-dB axial ratio bandwidth in the azimuth plane is very wide which achieves 54% (1.60-2.80 GHz). Additionally, the 3-dB axial ratio beamwidth is over 50˚ for radiation pattern in elevation plane. Moreover, the antenna achieves excellent omnidirectional right-hand CP performance with a variation of 0.5 dB in the azimuth plane and an average gain over 1.5 dB across the operating band, which are well applied to the wireless system.

1. Qian, Z. H., "Analysis of circularly polarized dielectric resonator antenna excited by a spiral slot," Progress In Electromagnetics Research, Vol. 47, 111-121, 2004.
doi:10.2528/PIER03102501

2. Mak, K. M. and K. M. Luk, "A circularly polarized antenna with wide axial ratio beamwidth," IEEE Trans. Antennas Propag., Vol. 57, No. 10, 3309-3312, Oct. 2009.

3. Yang, S. S., K.-F. Lee, A. A. Kishk, and K.-M. Luk, "Design and study of wideband single feed circularly polarized microstrip antennas," Progress In Electromagnetics Research, Vol. 80, 45-61, 2008.
doi:10.2528/PIER07110604

4. Heidari, A. A., M. Heyrani, and M. Nakhkash, "A dual-band circularly polarized stub loaded microstrip patch antenna for GPS applications," Progress In Electromagnetics Research, Vol. 92, 195-208, 2009.
doi:10.2528/PIER09032401

5. Wheeler, H. A., "A helical antenna for circular polarization," Proc. IRE, Vol. 35, No. 12, 1484-1488, Dec. 1947.
doi:10.1109/JRPROC.1947.234573

6. Cao, W. Q., A. J. Liu, B. N. Zhang, T. B. Yu, and Z. P. Qian, "Dual-band spiral patch-slot antenna with omnidirectional CP and unidirectional CP properties," IEEE Trans. Antennas Propag., Vol. 61, No. 4, 2286-2289, Apr. 2013.
doi:10.1109/TAP.2012.2235400

7. Kawakami, H. and R. Wakabayashi, "Research on circularly polarized conical beam antennas," IEEE Trans. Antennas Propag., Vol. 39, No. 3, 27-39, Jun. 1997.
doi:10.1109/74.598558

8. Yu, Y. F., S. L. He, and Z. X. Shen, "Electrically small omnidirectional antenna of circular polarization," 2012 IEEE Antennas and Propagation Society International Symposium (APSURSI), 1-2, 2012.

9. Hsiao, F. R. and K. L. Wong, "Low-profile omnidirectional circularly polarized antenna for WLAN access point," Microw. Opt. Technol. Lett., Vol. 46, No. 3, 227-231, 2005.
doi:10.1002/mop.20952

10. Lee, J. G. and J. H. Lee, "Zeroth order resonance loop antenna," IEEE Trans. Antennas Propag., Vol. 55, No. 3, 994-997, 2007.
doi:10.1109/TAP.2007.891875

11. Park, J. H., Y. H. Ryu, and J. H. Lee, "Epsilon negative zeroth order resonator antenna," IEEE Trans. Antennas Propag., Vol. 55, No. 12, 3710-3712, 2007.
doi:10.1109/TAP.2007.910505

12. Yoo, S. and S. Kahng, "CRLH ZOR antenna of a circular microstrip patch capacitively coupled to a circular shorted ring," Progress In Electromagnetics Research C, Vol. 25, 15-26, 2012.
doi:10.2528/PIERC11072803

13. Wei, K. P., Z. J. Zhang, Z. H. Feng, and M. F. Iskander, "A MNG-TL loop antenna array with horizontally polarized omnidirectional patterns," IEEE Trans. Antennas Propag., Vol. 60, No. 6, 2702-2710, Jun. 2012.
doi:10.1109/TAP.2012.2194643

14. Alford, A. and A. G. Kandoian, "Ultra-high frequency loop antenna," Electrical Engineering, Vol. 59, No. 12, 843-848, 1940.
doi:10.1109/EE.1940.6435249

15. Lin, C. C., L. C. Kuo, and H. R. Chuang, "A horizontally polarized omnidirectional printed antenna for WLAN applications," IEEE Trans. Antennas Propag., Vol. 54, No. 11, 3551-3556, Nov. 2006.
doi:10.1109/TAP.2006.884307

16. Park, B.-C. and J.-H. Lee, "Omnidirectional circularly polarized antenna utilizing zeroth-order resonance of epsilon negative transmission line," IEEE Trans. Antennas Propag., Vol. 59, No. 7, 2717-2721, Jul. 2011.
doi:10.1109/TAP.2011.2152337

17. Li, W. W. and K. W. Leung, "Omnidirectional circularly polarized dielectric resonator antenna with top-loaded Alford loop for pattern diversity design," IEEE Trans. Antennas Propag., Vol. 61, No. 8, 4246-4256, Aug. 2013.
doi:10.1109/TAP.2013.2262072

18. Pan, Y. M. and K. W. Leung, "Wideband omnidirectional circularly polarized dielectric resonator antenna with parasitic strips," IEEE Trans. Antennas Propag., Vol. 60, No. 6, 2992-2997, Jun. 2012.
doi:10.1109/TAP.2012.2194678

Dr. Long Yang

Dr. Neng-Wu Liu

Dr. Zhi-Ya Zhang

Dr. Guang Fu

Dr. Qiong-Qiong Liu

Dr. Shaoli Zuo