A novel low-index metamaterial lens (LIML) used for wideband circular polarization antenna is proposed. By introducing gradual spaces between metamaterial elements, one can achieve a much wider bandwidth than the equally spaced situation can do. Starting with a planar equiangular spiral antenna with reflector, we demonstrate the design idea of this LIML. By using the specially designed LIML, the ultimate antenna can achieve an obvious gain improvement of 2 dBi and a wide axial ratio bandwidth of 44% (from 6.9 GHz to 10.8 GHz). A prototype is fabricated, and the measured results agree well with the simulated ones.
2. Augustin, G., B. P. Chacko, and T. A. Denidni, "A zero-index metamaterial unit-cell for antenna gain enhancement," IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, 126-127, July 2013.
3. Zhou, H., Z. Pei, S. Qu, S. Zhang, J. Wang, Z. Duan, H. Ma, and Z. Xu, "A novel high-directivity microstrip patch antenna based on zero-index metamaterial," IEEE Antennas and Wireless Propag. Lett., Vol. 8, 538-541, 2009.
doi:10.1109/LAWP.2009.2018710
4. Lv, Y., F. Meng, J. Hua, and M. Chen, "A wideband zero index metamaterial lens for directive emission based on z-shaped meta-atom," 5th Global Symposium on Millimeter Waves (GSMM), 418-421, May 2012.
5. Turpin, J. P., Q. Wu, D. H. Werner, B. Martin, M. Bray, and E. Lier, "Low cost and broadband dual-polarization metamaterial lens for directivity enhancement," IEEE Trans. Antennas Propag., Vol. 60, 5717-5726, 2012.
doi:10.1109/TAP.2012.2214013
6. Louertain, K. and T. H. Chio, "Low-profile broadband spiral antenna with meta-materials," IEEE Antennas and Propagation Society International Symposium (APSURSI), 1331-1332, July 2014.
7. Trentini, G. V., "Partially reflecting sheet arrays," IEEE Trans. Antennas Propag., 666-671, 1956.
doi:10.1109/TAP.1956.1144455
8. Chen, X. D., T. M. Grzegorczyk, B. Wu, J. Pacheco, Jr., and J. A. Kong, "Rebuts method to retrieve constitutive effective parameters of metamaterials," Physical Review E, Vol. 70, 016608, 2004.
doi:10.1103/PhysRevE.70.016608
Submit
