A novel Yagi-Uda-like transmitarray is proposed for circularly polarized (CP) operation. The element consists of multiple strips stacked in parallel for achieving broad transmission phase range. By employing the design concept for the Yagi-Uda director, the transmitarray elements are made to provide the functions of phase shifter and director simultaneously. By introducing rotational offset into the stacking strips, the element is found to be able to generate circular polarization. To demonstrate the working principle, an 8-layer unit element is simulated using the Floquet method to provide a transmission phase range of 412˚. The proposed 5×5 full-fledged CP transmitarray is able to produce an antenna gain of 16.2 dBi, a -1-dB bandwidth of 4%, an axial-ratio bandwidth of 7%, and an aperture efficiency of 40.4%. A simple curve-fitted design equation is also given.
1. Abdelrahman, A. H., P. Nayeri, A. Z. Elsherbeni, and F. Yang, "Bandwidth improvement methods of transmitarray antennas," IEEE Trans. Antennas. Propag., Vol. 63, No. 7, 2946-2954, 2015. doi:10.1109/TAP.2015.2423706
2. Ryan, C. G. M., M. R. Chaharmir, J. Shaker, J. R. Bray, Y. M. M. Antar, and A. Ittipiboon, "A wideband transmitarray using dual-resonant double square rings," IEEE Trans. Antennas Propag., Vol. 58, No. 5, 1486-1493, 2010. doi:10.1109/TAP.2010.2044356
3. Datthanasombat, S., A. Prata, L. R. Amaro, and J. A. Harrell, "Layered lens antenna," Proc. IEEE Antennas Propag., 777-780, Boston, MA, USA, 2001.
7. Li, L., Q. Chen, Q. Yuan, K. Sawaya, T. Maruyama, T. Furuno, and S. Uebayashi, "Novel broadband planar reflectarray with parasitic dipoles for wireless communication applications," IEEE Antennas Wireless Propag. Lett., Vol. 8, 881-885, 2009.
8. Carrasco, E., M. Barba, J. A. Encinar, M. Arrebola, F. Rossi, and A. Freni, "Design, manufacture and test of a low-cost shaped-beam reflectarray using a single layer of varying-sized printed dipoles," IEEE Trans. Antennas Propag., Vol. 61, No. 6, 3077-3085, 2013. doi:10.1109/TAP.2013.2254431
10. Nakatani, D. and J. Ajioka, "Lens designs using rotatable phasing elements," Proc. IEEE Antennas Propag., Vol. 15, 357-360, 1977.
11. Hall, P. S. and M. S. Smith, "Sequentially rotated arrays with reduced sidelobe levels," IEEE Proc. Microw. Antennas Propag., Vol. 141, No. 4, 321-325, Aug. 1994. doi:10.1049/ip-map:19941193
12. Phillion, R. H. and M. Okoniewski, "Lenses for circular polarization using planar arrays of rotated passive elements," IEEE Trans. Antennas Propag., Vol. 59, No. 4, 1217-1227, 2011. doi:10.1109/TAP.2011.2109694
13. Palma, L. D., A. Clemente, L. Dussopt, R. Sauleau, P. Potier, and P. Pouliguen, "Circularly polarized transmitarray with sequential rotation in Ka-band," IEEE Trans. Antennas Propag., Vol. 63, No. 11, 5118-5124, 2015. doi:10.1109/TAP.2015.2474149
14. Yu, J., L. Chen, and X. Shi, "A multi-layer dipole-type element for circularly polarized transmitarray applications," IEEE Antennas Wireless Propag. Lett., Vol. 15, 1877-1880, 2016. doi:10.1109/LAWP.2016.2542211
16. Balanis, C. A., Antenna Theory: Analysis and Design, 3rd Ed., John Wiley & Sons, Mar. 2005.
17. Yu, A., F. Yang, A. Z. Elsherbeni, J. Huang, and Y. Rahmat-Samii, "Aperture efficiency analysis of reflectarray antennas," Microw. Opt. Technol. Lett., Vol. 52, 364-372, Feb. 2010. doi:10.1002/mop.24949