volume | PIER Journals

Abstract

A novel dual-band circularly polarized (CP) antenna with wide axial ratio (AR) and impedance bandwidths is proposed. Based on a rectangular ground, the antenna consists of a trapezoid patch, an L-shaped strip, a cavity, and T-shaped and L-shaped perturbations. By embedding a feeding line with a trapezoid patch and an L-shaped strip, dual-band input impedance performance and a CP performance at upper band are obtained. In order to achieve a CP performance at the lower band, a T-shaped perturbation is embedded inside the slot. Moreover, the CP performance is enhanced by inserting an L-shaped perturbation at the right bottom corner of the slot. Furthermore, using a cavity underneath the antenna, unidirectional radiation patterns with greatly gain enhancement are obtained. The measured results show that the impedance bandwidths for S₁₁<-10 dB are 22.7% (2.34-2.94 GHz) and 79.8% (4.64-10.8 GHz) while the axial ratio bandwidths (AR<3 dB) are 26.4% (2.3-3 GHz) and 12.6% (5.2-5.9 GHz) at the lower and upper bands, respectively. Additionally, the measured gain is more than 7.4 dB and 2.4 dB in the two operating bands, respectively. Thus, the antenna can be well applied for both 2.4/5.8 GHz WLAN bands and 2.5/5.5 GHz WiMAX bands.

1. Zhang, Z. Y., G. Fu, and S. L. Zuo, "A compact printed monopole antenna for WLAN and WiMAX applications," Microwave Opt. Technol. Lett., Vol. 52, No. 4, 857-861, Apr. 2010.
doi:10.1002/mop.25060

2. Wang, H. and M. Zheng, "An internal triple-band WLAN antenna," IEEE Antenna and Wireless Propag. Lett., Vol. 10, 569-572, Jun. 2011.
doi:10.1109/LAWP.2011.2158051

3. Lin, D. B., I. T. Tang, and Y. J. Wei, "Compact dual-band-notched CPW-fed wide-slot antenna for WLAN and WiMAX applications," Microwave Opt. Technol. Lett., Vol. 53, No. 7, 1496-1501, Apr. 2011.
doi:10.1002/mop.26042

4. Hsu, , S.-H. and K. Chang, "A novel recon¯gurable microstrip antenna with switchable circular polarization," IEEE Antenna and Wireless Propag. Lett., Vol. 6, 160-162, Feb. 2007.
doi:10.1109/LAWP.2007.894150

5. Sung, Y. J., T. U. Jang, and Y.-S. Kim, "A reconfigurable microstrip antenna for switchable polarization," IEEE Microw. Wirel. Compon. Lett., Vol. 14, No. 11, 534-536, Nov. 2004.
doi:10.1109/LMWC.2004.837061

6. Zhang, Z. Y., N. W. Liu, J. Y. Zhao, and G. Fu, "Wideband circularly polarized antenna with gain improvement," IEEE. Antenna Wireless Propagt. Lett., Vol. 12, 456-459, 2013.
doi:10.1109/LAWP.2013.2253591

7. Wu, Z. H., Y. Lou, and E. K. Yung, "A circular patch fed by a switch line balun with printed L-probes for broadband CP performance," IEEE. Antenna Wireless Propagt. Lett., Vol. 6, 608-611, 2007.
doi:10.1109/LAWP.2007.913330

8. Fu, G., Z. Y. Zhang, S. L. Zuo, J. Lei, and S. X. Gong, "A wideband circularly polarized antenna with Γ-shaped feed," Microw. Opt. Technol. Lett., Vol. 54, No. 1, 153-156, Jan. 2012.
doi:10.1002/mop.26503

9. Tsai, C.-L., "A coplanar-strip dipole antenna for broadband circular polarization operation," Progress In Electromagnetics Research, Vol. 121, 141-157, 2011.
doi:10.2528/PIER11082407

10. Kasabegoudar, V. G. and K. J. Vinoy, "A broadband suspended microstrip antenna for circular polarization," Progress In Electromagnetics Research, Vol. 90, 353-368, 2009.
doi:10.2528/PIER09012901

11. Zainud-Deen, S. H., H. A. Malhat, and K. H. Awadalla, "A single-feed cylindrical super quadric dielectric resonator antenna for circular polarization," Progress In Electromagnetics Research, Vol. 85, 409-424, 2008.
doi:10.2528/PIER08090904

12. Chen, C. H. and E. K. N. Yung, "Dual-band circularly-polarized CPW-fed slot antenna with a small frequency ratio and wide bandwidths," IEEE Trans. Antennas Propag., Vol. 59, No. 4, 1379-1384, Apr. 2011.
doi:10.1109/TAP.2011.2109347

13. Chen, C. H. and E. K. N. Yung, "Dual-band dual-sense circularly-polarized CPW-fed slot antenna with two spiral slots loaded," IEEE Trans. Antennas Propag., Vol. 57, No. 6, 1829-1833, Jun. 2009.
doi:10.1109/TAP.2009.2019990

14. Wu, T., X. W. Shi, P. Li, and H. Bai, "Trip-band microstrip-fed monopole antenna with dual-polarization characteristics for WLAN and WiMAX applications," Electron. Lett., Vol. 49, No. 25, Dec. 2013.
doi:10.1049/el.2013.3230

15. Li, W. M., B. Liu, and H. W. Zhao, "The U-shaped structure in dual-band circularly polarized slot antenna design," IEEE Antenna and Wireless Propag. Lett., Vol. 13, 447-450, Mar. 2014.
doi:10.1109/LAWP.2014.2306918

16. Deng, C. J., Y. Li, Z. J. Zhang, G. P. Pan, and Z. H. Feng, "Dual-band circularly polarized rotated patch antenna with a parasitic circular patch loading," IEEE Antenna and Wireless Propag. Lett., Vol. 12, 447-450, Apr. 2013.

17. Medeiros, C. R., E. B. Lima, J. R. Costa, and C. A. Fernandes, "Wideband slot antenna for WLAN access points," IEEE Antenna and Wireless Propag. Lett., Vol. 9, 79-82, 2010.
doi:10.1109/LAWP.2010.2043332

18. Kim, B., J. Ryu, H. Choo, H. Lee, and I. Park, "Dual ISM-band gap-filler microstrip antenna with wo Y-shaped sots for satellite internet service," Microwave Opt. Technol. Lett., Vol. 52, No. 8, 1825-1827, Aug. 2010.
doi:10.1002/mop.25325

19. Mobashsher, A. T., M. T. Islam, and N. Misran, "A novel high-gain dual-band antenna for RFID reader applications," IEEE Antenna and Wireless Propag. Lett., Vol. 9, 653-656, Apr. 2010.
doi:10.1109/LAWP.2010.2055818

Dr. Neng-Wu Liu

Dr. Ya-Li Yao

Dr. Zhi-Ya Zhang

Dr. Yang Li

Dr. Guang Fu

Dr. Shaoli Zuo