Design of Linear-to-Circular Polarization Transformers Made of Long Densely Packed Metallic Helices

In this work, we study the realization of realistic polarization transformers formed by long metallic helices. To this end, we propose a new homogenization model to characterize the propagation of electromagnetic waves in a medium formed by infinitely long helices. We derive approximate analytical expressions for the effective permittivity, effective permeability and the magnetoelectric tensor of the composite material, taking into account the effects of spatial dispersion. We apply the new homogenization model to characterize novel linear-to-circular polarization transformers. Our results show that the metamaterial screen may be designed in such a way that an incoming linearly polarized wave may be transformed into a circularly polarized transmitted wave, and that the transmission efficiency of such polarization transformer may be as high as 95%.

[1]  E. M. Lifshitz,et al.  Electrodynamics of continuous media , 1961 .

[2]  Nader Engheta,et al.  Optical nanotransmission lines: synthesis of planar left-handed metamaterials in the infrared and visible regimes , 2006, physics/0603052.

[3]  N. Engheta,et al.  An idea for thin subwavelength cavity resonators using metamaterials with negative permittivity and permeability , 2002, IEEE Antennas and Wireless Propagation Letters.

[4]  W. Boothby.  An introduction to differentiable manifolds and Riemannian geometry , 1975 .

[5]  Y. Hao,et al.  Subwavelength microwave imaging using an array of parallel conducting wires as a lens , 2006 .

[6]  N I Zheludev,et al.  Giant gyrotropy due to electromagnetic-field coupling in a bilayered chiral structure. , 2006, Physical review letters.

[7]  S. Tretyakov.  Analytical Modeling in Applied Electromagnetics , 2003 .

[8]  M. Silveirinha,et al.  Additional boundary condition for the wire medium , 2006, IEEE Transactions on Antennas and Propagation.

[9]  S A Tretyakov,et al.  Example of bianisotropic electromagnetic crystals: the spiral medium. , 2003, Physical review. E, Statistical, nonlinear, and soft matter physics.

[10]  K. Lindman,et al.  Über eine durch ein isotropes System von spiralförmigen Resonatoren erzeugte Rotationspolarisation der elektromagnetischen Wellen , 1920 .

[11]  Nader Engheta,et al.  Tunneling of electromagnetic energy through subwavelength channels and bends using epsilon-near-zero materials. , 2006, Physical review letters.

[12]  C. Fernandes,et al.  A hybrid method for the efficient calculation of the band structure of 3-D metallic crystals , 2004, IEEE Transactions on Microwave Theory and Techniques.

[13]  Sergei A. Tretyakov,et al.  Electromagnetics of bi-anisotropic materials: Theory and applications , 2001 .

[14]  M. Silveirinha,et al.  Effective Permittivity of Metallic Crystals: A Periodic Green's Function Formulation , 2003 .

[15]  F. Martín,et al.  Effective negative-/spl epsiv/ stopband microstrip lines based on complementary split ring resonators , 2004, IEEE Microwave and Wireless Components Letters.

[16]  Ismo V. Lindell,et al.  Electromagnetic Waves in Chiral and Bi-Isotropic Media , 1994 .

[17]  Dwight L. Jaggard,et al.  On electromagnetic waves in chiral media , 1979 .

[18]  Gianluca Lazzi.  IEEE AWPL Antennas and Wireless Propagation Letters , 2010 .

[19]  S. Tretyakov,et al.  Strong spatial dispersion in wire media in the very large wavelength limit , 2002, cond-mat/0211204.

[20]  Steven G. Johnson,et al.  Subwavelength imaging in photonic crystals , 2003 .

[21]  J. Pendry,et al.  Negative refraction makes a perfect lens , 2000, Physical review letters.

[22]  J. Pendry.  A Chiral Route to Negative Refraction , 2004, Science.

[23]  Mario G. Silveirinha.  Metamaterial homogenization approach with application to the characterization of microstructured composites with negative parameters , 2007 .

[24]  Pavel A. Belov,et al.  Subwavelength imaging at infrared frequencies using an array of metallic nanorods , 2007 .

[25]  A. Grbic,et al.  Overcoming the diffraction limit with a planar left-handed transmission-line lens. , 2004, Physical review letters.

[26]  C. Fernandes,et al.  Homogenization of 3-D-connected and nonconnected wire metamaterials , 2005, IEEE Transactions on Microwave Theory and Techniques.