A novel design of circularly polarized (CP) annular-ring microstrip antenna (ARMSA) working in TM11 mode is presented. The CP radiations of the proposed antenna are implemented by a 90° branch-line hybrid coupler placed at the inner part of the ARMSA. Since the ARMSA has narrow bandwidth and high-input impedance, a circular parasitic patch suspended above the ring is employed for not only improving the impedance matching and bandwidth, but enhancing the performances of axial ratio (AR). Due to the utilizing of parasitic patch and circular hybrid, the measured results are shown to attain a 10-dB return loss bandwidth of 31.2% (1300-1780 MHz) and a 3-dB AR bandwidth of 19.2% (1360-1650 MHz) respectively. The CP gain is 8.2 dB at 1.575 GHz. The proposed antenna is low profile and has a simple structure, therefore, it can be a good candidate for GPS portable terminal applications.
2. Nasimuddin, K., P. Esselle, and A. K. Verma, "Wideband circularly polarized stacked microstrip antennas," IEEE Antennas Wireless Propag. Lett., Vol. 6, 21-24, 2007.
doi:10.1109/LAWP.2006.890749
3. Ferrero, F., C. Luxey, G. Jacquemod, and R. Staraj, "Dual-band circularly polarized microstrip antenna for satellite applications," IEEE Antennas Wireless Propag. Lett., Vol. 4, 13-15, 2005.
doi:10.1109/LAWP.2004.841622
4. Baligar, J.-S., U. K. Revankar, and K. V. Acharya, "Broadband stacked annular ring coupled shorted circular microstrip antenna," Electron. Letters, Vol. 36, 1756-1757, Oct. 12, 2000.
doi:10.1049/el:20001286
5. Chen, H. M. and K. L. Wong, "On the circular polarization operation of annular-ring microstrip antennas," IEEE Trans. Antennas Propaga., Vol. 47, No. 8, 1289-1292, Aug. 1999.
doi:10.1109/8.791945
6. Lin, Y. F., H. M. Chen, and S. C. Lin, "A new coupling mechanism for circularly polarized annular-ring patch antenna," IEEE Trans. Antennas Propaga., Vol. 56, No. 1, 11-16, Jan. 2008.
doi:10.1109/TAP.2007.912961
7. Row, J.-S., "Design of aperture-coupled annular-ring microstrip antennas for circular polarization," IEEE Trans. Antennas Propaga., Vol. 53, No. 5, 1779-1784, May 2005.
doi:10.1109/TAP.2005.846809
8. Guo, Y.-X., L. Bian, and X. Q. Shi, "Broadband circularly polarized annular-ring microstrip antennas," IEEE Trans. Antennas Propaga., Vol. 57, No. 8, 2474-2477, Aug. 2009.
9. Dahelle, J. S. and K. F. Lee, "Characteristics of annular ring microstrip antenna," Electron. Letters,, Vol. 18, 1051-1052, Nov. 1982.
10. Liu, H. and X. F. Hu, "Input impedance analysis of a microstrip annular-ring antenna with a thick substrate," Progress In Electromagnetic Research, Vol. 12, 177-204, 1996.
11. Pozar, D. M., Microwave Engineering, 2nd Ed., Vol. 379, No. 384, John Wiley, New York, 1998.
12. Garcia, Q., "Broadband stacked annular ring," Ninth International Conference on Antennas and Propagation, Vol. 1, 508-512, 1995.
Submit
