volume | PIER Journals

Abstract

In this work, ideally hard struts with different cross sections are analyzed. Firstly, the characterization of the invisibility of a given object in terms of an equivalent blockage width is discussed. Then, the effect of the incidence angle on struts for reducing electromagnetic blockage using the same ideally hard cylinders is analyzed. It is shown that the variation of incidence angle in azimuth is very sensitive in terms of blockage for both polarizations. Finally, design charts for ideally hard struts which reduce blockage simultaneously for TE and TM cases are presented. This can be used to define some performance goals for final realized struts.

1. Fante, R. L. and M. T. McCornack, "Reflection properties of the salisbury screen," IEEE Trans. on Antennas and Propagation, Vol. 36, No. 10, 1443-1454, October 1988.
doi:10.1109/8.8632

2. Ward, J. and Towards invisible glass, Vacuum, Vol. 22, 369-375, 1972.
doi:10.1016/0042-207X(72)91655-7

3. Alu, A. and N. Engheta, "Achieving transparency with plasmonic and metamaterial coatings," Physical Review E, Vol. 72, 016623, July 2005.

4. Schurig, D., J. Mock, B. Justice, S. Cummer, J. Pendry, A. Starr, and D. Smith, "Metmaterial elecromagnetic cloak at microwave frequencies," Science, Vol. 314, No. 5801, 977-980, November 2006.
doi:10.1126/science.1133628

5. Nicorovici, N., G. Milton, R. McPhedern, and L. C. Botten, "Quasistatic cloaking of two-dimensional polarizable discrete systems by anomalous resonance," Optics Express, Vol. 15, No. 10, 6314-6323, May 2007.
doi:10.1364/OE.15.006314

6. Alitalo, P., O. Luukkonen, L. Jylh, J. Venermo, and S. A. Tretyakov, "Transmission-line networks cloaking objects from electromagnetic fields ," IEEE Trans. on Antennas and Propagation, Vol. 56, No. 2, 416-424, February 2008.
doi:10.1109/TAP.2007.915469

7. Alu, A. and N. Engheta, "Cloaking and transparency for collections of particles with metamaterial and plasmonic covers," Optics Express, Vol. 15, No. 12, 7578-7590, June 2007.
doi:10.1364/OE.15.007578

8. Xi, S., H. Chen, B. I.Wu, and J. A. Kong, "One-directional perfect cloak created with homogeneous material," IEEE Microwave and Wireless Components Letters, Vol. 19, No. 3, 131-133, March 2009.
doi:10.1109/LMWC.2009.2013677

9. Ivsic, B., Z. Sipus, and S. Hrabar, "Analysis of uniaxial multilayer cylinders used for invisible cloak realization," IEEE Trans. on Antennas and Propagation, Vol. 57, No. 5, 1521-1527, May 2009.
doi:10.1109/TAP.2009.2016695

10. Kildal, P. S., "Artificially soft and hard surfaces in electromagnetics," IEEE Trans. on Antennas and Propagation, Vol. 28, No. 10, 1537-1544, October 1990.

11. Kildal, P. S. and A. A. Kishk, "EM modeling of surfaces with stop or go characteristics --- Artificial magnetic conductors and soft and hard surfaces," Applied Computational Electromagnetics Society Journal, Vol. 18, No. 1, 32-40, October 2003.

12. Kildal, P. S., E. Olsen, and J. A. Aas, "Losses, sidelobes and cross-polarization caused by feed-support struts in reflector antennas: Design curves," IEEE Trans. on Antennas and Propagation, Vol. 36, No. 2, 182-190, February 1988.
doi:10.1109/8.1095

13. Kildal, P. S., A. A. Kishk, and A. Tengs, "Reduction of forward scattering from cylindrical objects using hard surfaces," IEEE Trans. on Antennas and Propagation, Vol. 44, No. 11, 1509-1520, November 1996.
doi:10.1109/8.542076

14. Kay, A. F., "Electrical design of metal space frame radomes," IEEE Trans. on Antennas and Propagation, Vol. 13, No. 2, 188-202, March 1965.
doi:10.1109/TAP.1965.1138397

15. Rusch, W. V. T., J. Appel-Hansen, C. A. Klein, and R. Mittra, "Forward scattering from square cylinders in the resonance region with application to aperture blockage," IEEE Trans. on Antennas and Propagation, Vol. 24, No. 2, 182-189, March 1976.
doi:10.1109/TAP.1976.1141307

16. Ishimaru, A., "Electromagnetic Wave Propagation, Radiation and Scattering," Prentice-Hall, 1991.

17. Kishk, A. A. and P. S. Kildal, "Asymptotic boundary conditions for strip-loaded scattterers applied to circular dielectric cylinders under oblique incidence," IEEE Trans. on Antennas and Propagation, Vol. 45, No. 1, 51-56, January 1997.
doi:10.1109/8.554240

18. Rajo-Iglesias, E., J. M. Fernandez, and P. S. Kildal, "Blockage reduction of rhombic cylinders using meta-surfaces," Proc. of IEEE AP-S International Symposium 2008, 1-4, July 2008.

19. Jacobsson, P., L. Yueqiang, and T. Rylander, "Reduction of total scattering from antenna struts using shape optimization," RVK 05-Radiovetenskap och Kommunikation, 2005.

Dr. Jose-Manuel Fernandez Gonzalez

Dr. Eva Rajo-Iglesias

Prof. Manuel Sierra-Castaner