A new reconfigurable microstrip patch antenna allowing switching between two circular polarizations is proposed. It consists of a square radiating patch and a 3 dB hybrid coupler. Using only a single-polar-double-throw (SPDT) switch,the polarization switching can be achieved. This design of the dc-bias network is extremely simple. From experimental results,the proposed antenna avoids the frequency offset phenomena which often happened to antennas with switchable polarization.
3. Yang, F. and Y. Rahmat-Samii, "A reconfigurable patch antenna using switchable slots for circular polarization diversity," IEEE Microwave and Wireless Components Letters, Vol. 12, No. 3, 96-98, 2002. doi:10.1109/7260.989863
4. Kossel, M. A., R. Kung, H. Benedickter, and W. Biichtokd, "An active tagging system using circular-polarization modulation," IEEE Transactions on Microwave Theory and Techniques, Vol. 47, No. 12, 2242-2248, 1999. doi:10.1109/22.808966
5. Alkanhal, M. and A. F. Sheta, "A novel dual-band reconfigurable square-ring microstrip antenna," Progress In Electromagnetics Research, Vol. 70, 337-349, 2007. doi:10.2528/PIER07020703
6. Shynu, S. V., G. Augustin, C. K. Aanandan, P . Mohanan, and K. Vasudevan, "Design of compact reconfigurable dual frequency microstrip antenna using varactor diodes," Progress In Electromagnetics Research, Vol. 60, 197-205, 2006. doi:10.2528/PIER05120101
7. Wu, W. and Y.-H. Bi, "Switc hed-beam planar fractal antenna," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 3, 409-415, 2006. doi:10.1163/156939306775701786
8. Wu, W., B.-Z. Wang, and S. Sun, "P attern reconfigurable microstrip patch antenna," Journal of Electromagnetic Waves and Applications, Vol. 19, No. 1, 107-113, 2005. doi:10.1163/1569393052955125
9. Chen, Y. B., T. B. Chen, Y. C. Jiao, and F. S. Zhang, "A Reconfigurable microstrip antenna with switchable polarization," Journal of Electromagnetic Waves and Applications, Vol. 20, No. 10, 2006. doi:10.1163/156939306779276820
10. Fries, M. K., M. Grani, and R. Vahldieck, "A reconfigurable slot antenna with switchable polarization," IEEE Microwave and Wireless Components Letters, Vol. 13, No. 11, 490-492, 2003. doi:10.1109/LMWC.2003.817148
11. Haskins, P . M. and J. S. Dahele, "V aractor-diode loaded passive polarisation-agile patch antenna," Electronics Letters, Vol. 30, No. 6, 1074-1075, 1994. doi:10.1049/el:19940720
12. Ho, M. H., M. T.Wu, C. G. Hsu, and J. Y. Sze, "An RHCP/LHCP switchable slotline-fed slot-ring antenna," Microwave and Optical Technology Letters, Vol. 46, 30-33, 2005. doi:10.1002/mop.20892
13. Boti, M., L. Dussopt, and J.-M. Laheurte, "Circularly polarised antenna with switchable polarisation sense," Electronics Letters, Vol. 36, No. 8, 1518-1519, 2000. doi:10.1049/el:20001098
14. Nanbo, J., Y. Fan, and Y. Rahmat-Samii, A novel reconfigurable patch antenna with both frequency and polarization diversities for wireless communications, 2004 IEEE Antennas and Propagation Society International Symposium, Vol. 2, No. 6, 1796-1799, 2004.