Accession Number : ADA506707


Title :   Electromagnetic Field Control and Optimization Using Metamaterials


Descriptive Note : Doctoral thesis


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT


Personal Author(s) : McGuirk, Jeffrey S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a506707.pdf


Report Date : Dec 2009


Pagination or Media Count : 168


Abstract : Transformation optics has shown the ability to cloak an object from incident electromagnetic radiation is possible. However, the material parameters are inhomogeneous, anisotropic, and, in some instances, singular at various locations. In order for a cloak to be practically realized, simplified parameter sets are required. However, the simplified parameters result in a degradation in the cloaking function. Constitutive parameters for simplified two-dimensional cylindrical cloaks have been developed with two material property constraints. It was initially believed satisfying these two constraints would result in the simplified cylindrical cloaks having the same wave equation as an ideal cloak. Because of this error, the simplified cloaks were not perfect. No analysis was done to determine all material parameter constraints to enable a perfect two-dimensional cylindrical cloak. This research developed a third constraint on the material parameters. It was shown as the material parameters better satisfy this new equation, a two-dimensional cylindrical cloak's hidden region is better shielded from incident radiation. Additionally, a novel way to derive simplified material parameters for two-dimensional cylindrical cloaks was developed. A Taylor series expansion dictated by the new constraint equation leads to simplified cloaks with significantly improved scattering width performances when compared to previous published results. During the course of this research, it was noted all cloak simulations are performed using finite element method (FEM) based numerical methods. A Green's function was used to accurately calculate scattering widths from a two-dimensional cylindrical cloak with a perfect electrically conducting inner shell.


Descriptors :   *MATERIALS , *ELECTROMAGNETIC FIELDS , *ELECTROMAGNETIC RADIATION , *OPTIMIZATION , TWO DIMENSIONAL , FINITE ELEMENT ANALYSIS , HOMOGENEITY , EIGENVALUES , CYLINDRICAL BODIES , ANISOTROPY , GREENS FUNCTIONS , DECOMPOSITION , SIMPLIFICATION , ELECTROMAGNETISM , TRANSFORMATIONS , PARAMETERS , COMPUTATIONS , OPTICS , CONTROL , THESES


Subject Categories : Electricity and Magnetism
      Electromagnetic Pulses


Distribution Statement : APPROVED FOR PUBLIC RELEASE