In this paper we present the full process of designing anisotropic metamaterial (MM) wide angle impedance matching (WAIM) layers. These layers are used to reduce the scan losses that occur in active phased arrays for large scanning angles. Numerical results are provided to show the improvement in performances that such layers can ensure. The proposed anisotropic MM-WAIM layers achieve an improvement of about 1 dB of more radiated power at θ = 70˚ from broadside, in a 13% of fractional bandwidth on the azimuthal plane Φ = 90˚. Weaker improvements are obtained in the other azimuthal planes, however keeping the active reflection coefficient below -9 dB for all azimuthal planes up to θ = 60˚ and up to θ = 70˚ off-axis for planes Φ = 45˚; 90˚ in the whole operational band.
1. Magill, E. G. and H. A. Wheeler, "Wide-angle impedance matching of a planar array antenna by a dielectric sheet," IEEE Transactions on Antennas and Propagation, Vol. 14, No. 1, January 1966. doi:10.1109/TAP.1966.1138622
2. Hannan, P. W., D. Lerner, and G. Knittel, "Impedance matching a phased-array antenna over wide scan angles by connecting circuits," IEEE Transactions on Antennas and Propagation, Vol. 13, No. 1, January 1965. doi:10.1109/TAP.1965.1138365
3. Hansen, R. C., Phased Array Antennas, 2nd Ed., John Wiley & Sons, Inc., Hoboken, New Jersey, 2009. doi:10.1002/9780470529188
4. Pendry, J., A. Holden, W. Stewart, and I. Youngs, "Extremely low frequency plasmons in metallic mesostructures," Physical Review Letters, Vol. 76, No. 25, June 1996. doi:10.1103/PhysRevLett.76.4773
5. Pendry, J. B., A. J. Holden, D. J. Robbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Transactions on Microwave Theory and Techniques, Vol. 47, No. 11, 2075-2084, November 1999. doi:10.1109/22.798002
6. Smith, D. R., J. B. Pendry, and M. C. K. Wiltshire, "Metamaterials and negative refractive index," Science, Vol. 305, August 2004.
7. Sajuyigbe, S., M. Ross, P. Geren, S. A. Cummer, M. H. Tanielian, and D. R. Smith, "Wide angle impedance matching metamaterials for waveguide-fed phased-array antennas," IET Microwaves, Antennas & Propagation, Vol. 4, No. 8, 1063-1072, August 2010. doi:10.1049/iet-map.2009.0543
8. Oliveri, G., F. Viani, N. Anselmi, and A. Massa, "Synthesis of multilayer WAIM coatings for planar-phased arrays within the system-by-design framework," IEEE Transactions on Antennas and Propagation, Vol. 63, No. 6, 2482-2496, June 2015. doi:10.1109/TAP.2015.2415516
9. Rodriguez-Ulibarri, P., M. Beruete, F. Falcone, T. Crepin, C. Martel, F. Boust, C. Loecker, K. Herbertz, C. Salzburg, T. Bertuch, J. P. Martinaud, T. Dousset, and J. A. Marcotegui, "Metaradome for blind spot mitigation in phased-array antennas," 2014 8th European Conference on Antennas and Propagation (EuCAP), 2504-2508, April 6-11, 2014.
10. Silvestri, F., P. Chiusolo, L. Cifola, R. Bolt, and G. Gerini, "Design of metamaterial based wide angle impedance matching layers for active phased arrays," 2015 9th European Conference on Antennas and Propagation (EuCAP), 1-5, April 13-17, 2015.
12. Borgiotti, G. V., "A novel expression for the mutual admittance of planar radiating elements," IEEE Transactions on Antennas and Propagation, Vol. 16, No. 3, 329-333, May 1968. doi:10.1109/TAP.1968.1139185
13. Cameron, T. and G. Eleftheriades, "Analysis and characterization of a wide-angle impedance matching metasurface for dipole phased arrays," IEEE Transactions on Antennas and Propagation, accepted for publication.
14. Hansen, R. C., Microwave Scanning Antennas, Academic Press, 1966.
15. ANSYS R Electromagnetics Suite 15.0.0, ANSYS R HFSS 2014, c 2013 SAP IP, Inc., .
16. Ludwig, A. C., "The definition of cross polarization," IEEE Transactions on Antennas and Propagation, Vol. 21, 116-119, January 1973. doi:10.1109/TAP.1973.1140406
17. Bhattacharyya, A. K., Phased Array Antennas, John Wiley & Sons, Inc., Hoboken, NJ, 2006.
18. Haupt, R. L. and D. H. Werner, Genetic Algorithms in Electromagnetics, Wiley IEEE Press, 2007. doi:10.1002/047010628X
19. Matlab c R2011b, The Mathworks Inc., .
20. Martini, E., G. M. Sardi, and S. Maci, "Homogenization processes and retrieval of equivalent constitutive parameters for multisurface-metamaterials," IEEE Transactions on Antennas and Propagation, Vol. 62, No. 4, 2081-2092, April 2014. doi:10.1109/TAP.2014.2300169
21. Chen, X., T. Grzegorczyk, B. I. Wu, J. Pacheco, and J. Kong, "Robust method to retrieve the constitutive effective parameters of metamaterials," Physical Review E, Vol. 70, No. 1, July 2007.
22. Jiang, Z. H., J. A. Bossard, X. Wang, and D. H. Werner, "Synthesizing metamaterials with angularly independent e®ective medium properties based on an anisotropic parameter retrieval technique coupled with a genetic algorithm," Journal of Applied Physics, Vol. 109, 013515, January 2011. doi:10.1063/1.3530849