Electromagnetic Scattering From Conducting Circular Cylinder Coated by Meta-Materials and Loaded With Helical Strips Under Oblique Incidence

Abstract

Abstract-The asymptotic strip boundary condition (ASBC) isapplied to analyze the solution of the electromagnetic scattering from a conducting cylinder coated with a homogeneous linear material layer and loaded with conducting helical strips. Such homogeneous material layer can be implemented by a conventional dielectric material, a single negative (SNG) or double negative (DNG) meta-material layer. A study of different materials' constitutive parameters is presented with accordance to Drude and Lorentz material modeling. The boundary condition assumes that the strips are rounded around the coated cylinder in a helical form and both the strip's period and the spacing between the helix turns are very small and mathematically approaching the zero. Scattering due to normal and oblique incident plane waves (θ i , φ i ) of arbitrary polarization using the series solution is also computed. A number of parametric studies were investigated to illustrate the advantages of using metamaterials compared with conventional coating materials in terms of strip's rounding pitch angle and coating layer electrical thickness variations. It is also shown that for SNG materials, modified Bessel functions are used to accept negative arguments. Coating with metamaterials proves to achieve higher forward scattering compared with conventional materials for the same electrical coating thickness.

INFLUENCE OF TIME AND TEMPERATURE ON RESISTIVITY AND MICROSTRUCTURE OF Cu_x Co_1-x Fe₂ O₄ MIXED FERRITES

“…This results higher conductivity in the samples as a consequence of decrease in resistivity [28]. The presence of air gaps between the grains result in the formation of inhomogeneous dielectric structure.…”

Efficient Electrically Small Prolate Spheroidal Antennas Coated With a Shell of Double-Negative Metamaterials

“…However, with the development of new materials, such as MTMs, there is a new challenging opportunity to solve this limitation. MTMs are artificial constructed materials which are engineered media having qualitatively new response functions that do not occur or may not be easily available in nature [7], which have gained increasing interest [8][9][10][11][12][13][14][15][16][17][18][19][20]. Efficient electrically small antennas have been constructed by coating a DNG or epsilon-negative (ENG) MTMs shell [8,9], which have both large overall efficiency and large FBW.…”

Impedance Vibrator With Arbitrary Point of Excitation

“…So, for example, location of different active and passive elements in definite points along the length of a vibrator's antenna and also vibrator's excitation in a distinctive from its centre point create additional opportunities to form the set electrodynamic characteristics of vibrator radiators [1][2][3][4][5]. From our point of view, thin vibrators, on the surface of which impedance boundary conditions are performed, can serve these aims [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. In the proposed paper the approximate analytical solution of the current integral equation in a thin impedance vibrator with the arbitrary point of excitation has been obtained.…”