Ferromagnetic Nanowire Metamaterials: Theory and Applications
ABSTRACT An overview of ferromagnetic nanowire (FMNW) metamaterials is presented. First, FMNW metamaterials are placed in the historical context of antique composites and 20th Century artificial dielectrics, and presented as an example of second-generation metamaterials following the microstructured metamaterials developed in the first part of the decade. Next, the fabrication processes of FMNW metamaterials and subsequent planar devices are detailed. It is then shown how the geometrical properties of the FMNW structure, such as the wire diameter and the wire nanodisk thicknesses, determine the dc and RF responses of the material. Upon this basis, the modeling of the metamaterial is presented, using a two-level approach where the microscopic (with respect to the wires) susceptibility is derived by solving the Landau-Lifshitz equation and the macroscopic (metamaterial) permittivity and permeability tensors are obtained by effective medium theory. Next, a review of FMNW microwave devices, such as circulators, isolators, and phase shifters, is provided, and the example of an FMNW dual-band edge-mode isolator is studied. Finally, spintronic effects and applications of FMNW metamaterials, such as dc to RF generators and detectors based on the spin-torque transfer phenomenon, are reviewed.
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ABSTRACT: The perfect electromagnetic conductor (PEMC) was recently theoretically introduced by Lindell and Sihvola as a fundamental hypothetical electromagnetic medium. This papers proposes three related but distinct implementations - a ferrite, a magnet-less non-reciprocal metamaterial (MNM) and a graphene implementation - of a practical PEMC boundary. These implementations are all based on the combination of Faraday rotation and reflection from a conductive ground, but exhibit distinct and complementary features.Electromagnetic Theory (EMTS), Proceedings of 2013 URSI International Symposium on; 01/2013
Conference Paper: A personal perspective on CRLH antennas[Show abstract] [Hide abstract]
ABSTRACT: The author presents a personal perspective on the work that he and his collaborators have done in the area of composite right/left-handed (CRLH) antennas over the past decade with some emphasis on recent developments.Electromagnetic Theory (EMTS), Proceedings of 2013 URSI International Symposium on; 01/2013
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ABSTRACT: This paper investigates the generalized case of scattering from a planar grid, containing infinite numbers of axially magnetized ferromagnetic microwires placed parallel to each other in free space. A semi-analytical solution is obtained by calculating the local field at the surface of the reference microwire which is the sum of the scattered field from the other microwires as well as the incident field. Graf's theorem is used to transform the scattered field from one coordinate system to the other. Scattering field coefficients for the reference microwire are obtained by matching the tangential field components at the surface of the reference microwire. Simulated results are expressed in terms of the Reflection, Transmission and Absorption Coefficients for the T M z and T E z polarizations. For validation, results of the proposed analysis specialized to the case of normal incidence with T M z polarization are compared with the results available in the literature.Progress In Electromagnetics Research M 03/2014; 35(2014):1-10.