1. 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
2. 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
3. Liao, W. and Q.-X. Chu, "Dual-band circularly polarized microstrip antenna with small frequency ratio," Progress In Electromagnetics Research Letters, Vol. 15, 145-152, 2010.
doi:10.2528/PIERL10052101
4. Chen, X., G. Fu, S.-X. Gong, et al. "Circularly polarized stacked annular-ring microstrip antenna with integrated feeding network for UHF RFID readers," IEEE Antennas Wireless Propag. Lett., Vol. 9, 542-545, 2010.
doi:10.1109/LAWP.2010.2051791
5. Chen, H. M. and K. L. Wong, "On the circular polarization operation of annular-ring microstrip antenna," IEEE Trans. Antennas Propag., Vol. 47, No. 8, 1289-1292, 1999.
doi:10.1109/8.791945
6. Row, J. S., "Dual-frequency circularly polarised annular-ring microstrip antenna," Electron. Lett., Vol. 40, No. 3, 153-154, 2004.
doi:10.1049/el:20040123
7. Lin, , Y. F., H. M. Chen, and S. C. Lin, "A new coupling mechanism for circularly polarized annular-ring patch antenna," IEEE Trans. Antennas Propag., Vol. 56, No. 1, 11-15, 2008.
doi:10.1109/TAP.2007.912961
8. Row, J. S., "Design of aperture-coupled annular-ring microstrip antennas for circular polarization," IEEE Trans. Antennas Propag., Vol. 53, No. 5, 1779-1784, 2005.
doi:10.1109/TAP.2005.846809
9. Guo, Y. X., L. Bian, and X. Q. Shi, "Broadband circularly polarized annular-ring microstrip antenna," IEEE Trans. Antennas Propag., Vol. 56, No. 1, 2474-2477, 2009.
10. Su , C. W., S. K. Huang, and C. H. Lee, "CP microstrip antenna with wide beamwidth for GPS band application," Electron. Lett., Vol. 43, No. 20, 1062-1063, 2007.
doi:10.1049/el:20071691
11. Hang , J., "Circularly polarized conical patterns from circular microstrip antennas," IEEE Trans. Antennas Propag., Vol. 32, No. 9, 991-994, 1984.
doi:10.1109/TAP.1984.1143455
12. Lin, , S. Y. and K. L. Wong, "A conical-pattern annular-ring microstrip antenna with a photonic bandgap ground plane," Microw. Opt. Technol. Lett., Vol. 30, No. 3, 159-161, 2001.
doi:10.1002/mop.1251
13. Lin, S. Y. and K. C. Huang, "A compact microstrip antenna for GPS and DCS application," IEEE Trans. Antennas Propag., Vol. 53, No. 3, 1227-1229, 2005.
doi:10.1109/TAP.2004.842597