Transformation Electromagnetics for Antenna Applications



In recent years, transformation electromagnetics has found potential applications in propagation, waveguiding, scattering, and radiation. For antenna applications, using transformation techniques, one can transform bulky antennas to low profile ones. In general, the resulting medium will be both inhomogeneous and anisotropic. In this chapter, we proposed a spherical core-shell structure which can achieve arbitrarily large directivity. We investigated the problem by finding the transformed constitutive tensors and solving the equivalent problem in the core-shell configuration. Using the Ricatti-Bessel functions, we can represent the field components with Debye potentials and subsequently solve for the fields in all regions. We applied the formulation to several cases of dipole arrays within the shell, corresponding to both free-space and half-space problems in the virtual space. Overall, the calculation demonstrated that the formation of virtual aperture is indeed theoretically possible and the effects of loss on the number of available spherical harmonics and directivity are investigated.


Compression Ratio Transmission Coefficient Loss Tangent Virtual Space Constitutive Parameter 
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This work is in part supported by the Air Force Office of Scientific Research.


  1. 1.
    Zhang JJ, Luo Y, Chen HS, Wu BI (2008) Manipulating the directivity of antennas with metamaterial. Optics Express 16:10962–10967CrossRefGoogle Scholar
  2. 2.
    Pendry JB, Schurig D, Smith DR (2006) Controlling electromagnetic fields. Science 312:1780–1782MathSciNetMATHCrossRefGoogle Scholar
  3. 3.
    Leonhardt U, Philbin TG (2006) General relativity in electrical engineering. New J Phys 8:247CrossRefGoogle Scholar
  4. 4.
    Chu LJ (1948) Physical limitations of omni-directional antennas. J Appl Phys 19:1163–1175CrossRefGoogle Scholar
  5. 5.
    Zhang BL, Wu BI, Chen HS (2009) High directive antenna with virtual aperture. In: Proceedings 2009 IEEE APS International, Symposium, pp 3506–3509Google Scholar
  6. 6.
    Kong JA (2008) Electromagnetic wave theory. EMW, CambridgeGoogle Scholar
  7. 7.
    Kildishev AV, Cai W, Chettiar UK, Shalaev VM (2008) Transformation optics: approaching broadband electromagnetic cloaking. New J Phys 10:115209CrossRefGoogle Scholar
  8. 8.
    Chew WC (1995) Waves and fields in inhomogeneous media. IEEE Press, PiscatawayGoogle Scholar
  9. 9.
    Stratton JA (2007) Electromagnetic theory. IEEE Press, PiscatawayGoogle Scholar
  10. 10.
    Chen HS, Wu BI, Zhang BL, Kong JA (2007) Electromagnetic wave interactions with a metamaterial cloak. Phys Rev Lett 99:063903CrossRefGoogle Scholar
  11. 11.
    Zhang BL, Chen HS, Wu BI, Kong JA (2008) Extraordinary surface voltage effect in the invisibility cloak with an active device inside. Phys Rev Lett 100:063904CrossRefGoogle Scholar
  12. 12.
    Abramowitz M, Stegun I (1965) Handbook of mathematical functions. Dover, New YorkGoogle Scholar
  13. 13.
    Zhang BL (2009) Electromagnetics of transformation media. Dissertation, MITGoogle Scholar
  14. 14.
    Wu BI, Grzegorczyk TM, Zhang Y, Kong JA (2003) Guided modes with imaginary transverse wavenumber in a slab waveguide with negative permittivity and permeability. J Appl Phys 93:9386–9389CrossRefGoogle Scholar
  15. 15.
    Lu J, Grzegorczyk TM, Wu BI, Pacheco J, Chen M, Kong JA (2005) Effect of poles on subwavelength focusing by an LHM slab. Microwave Opt Technol Lett 45:49–53CrossRefGoogle Scholar

Copyright information

© Springer-Verlag London 2014

Authors and Affiliations

  1. 1.Sensors DirectorateAir Force Research LaboratoryDaytonUSA

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