Mohamed H. Al Sharkawy

OBLIQUE INCIDENCE PLANE WAVE SCATTERING FROM AN ARRAY OF CIRCULAR DIELECTRIC CYLINDERS

A rigorous semi-analytical solution is presented for electromagnetic scattering from an array of circular cylinders due to an obliquely incident plane wave. The cylinders are illuminated by either TMz or TEz incident plane wave. The solution is based on the application of the boundary conditions on the surface of each cylinder in terms of the local coordinate system of each individual cylinder. The principle of equal volume model is used to represent cylindrical cross-sections by an array of circular cylinders for both dielectric and conductor cases in order to proof the validity of the presented technique.

Plane wave scattering from three dimensional multiple objects using the iterative multiregion technique based on the FDFD method

An iterative approach using the finite difference frequency domain method is presented in this paper in order to solve the problem of scattering from large three-dimensional electromagnetic scatterers. The idea of iterative multiregion technique is introduced to divide one computational domain into smaller subregions and solve each subregion separately. Then the subregion solutions are combined iteratively to obtain a solution for the complete domain. As a result, a considerable reduction in the computation time and memory has been achieved.

Scattering of Obliquely Incident Plane Wave by an Array of Parallel Concentric Metamaterial Cylinders

A rigorous semi-analytical solution is presented for electromagnetic scattering from an array of parallel-coated circular cylinders of arbitrary radii and positions due to an obliquely incident TMz plane wave excitation. In order to check the validity of this technique, the radar cross-section of a single coated cylinder, a linear array of cylinders, and an arbitrary position array of cylinders are calculated and compared with available data in the literature. Furthermore, the near field is calculated to prove the validity of the boundary conditions on the surface of any cylinder with obliquely incidence wave. As an application, circular metamaterial cylinders are used to show the effect of metamaterial characteristics in altering the forward and backward scattering and in focusing the near field around the objects. 286 Henin, Al Sharkawy, and Elsherbeni

ELECTROMAGNETIC SCATTERING FROM PARALLEL CHIRAL CYLINDERS OF CIRCULAR CROSS- SECTIONS USING AN ITERATIVE PROCEDURE

The electromagnetic scattering from a 2D chiral circular cylinders, illuminated by either a TEz or a TMz plane wave, is investigated using an iterative scattering procedure. The developed formulation and the implemented code simulate different types of cylinders, where the cylinders can be made of anisotropic chiral material with uniform or non-uniform chiral admittance distribution, homogeneous isotropic dielectric material, perfectly conducting material or a combination of all of them. The technique applies the boundary conditions on the surface of each cylinder in an iterative procedure in order to solve for the field expansion coefficients. Numerical verifications are presented to prove the validity of the formulation before presenting the scattering from an array of chiral cylinders showing significant RCS reduction in forward or backward directions based on the selection of the chirality parameter.

Stacked elliptical dielectric resonator antennas for wideband applications

The work presents an improvement in the bandwidth of the dielectric resonator antenna (DRA) using a stacked elliptical DRA configuration placed above an infinite ground plane. The feed is a coaxial probe, providing proper wideband matching. The input impedance, the return loss and the radiation pattern were computed using the software package WIPL-D. Parametric studies were investigated for assessment of the antenna performance, resulting in an improved bandwidth of 61.5% (8 GHz) based on a -10 dB return loss for a 50 /spl Omega/-transmission line.

A graphical user interface (GUI) for electromagnetic scattering from two- and three-dimensional canonical and non-canonical objects

Various numerical techniques have been developed for modeling electromagnetic-field propagation in conducting and dielectric media. The validity of these techniques is usually verified by comparison to the exact or asymptotic solutions of canonical or non-canonical problems of well-known solutions. This paper presents a software package designed as an educational and validation tool for the purpose of visualizing the physical phenomena of electromagnetic scattering from some canonical and non-canonical objects. The package is constructed to provide solutions for dielectric and conductive materials wherever appropriate, and it calculates and displays the near and far fields due to an excitation from a line source or a plane wave

A graphical user interface (GUI) for electromagnetic scattering from two- and three-dimensional canonical and non-canonical objects [EM Programmer's Notebook]

Various numerical techniques have been developed for modeling electromagnetic-field propagation in conducting and dielectric media. The validity of these techniques is usually verified by comparison to the exact or asymptotic solutions of canonical or non-canonical problems of well-known solutions. This paper presents a software package designed as an educational and validation tool for the purpose of visualizing the physical phenomena of electromagnetic scattering from some canonical and non-canonical objects. The package is constructed to provide solutions for dielectric and conductive materials wherever appropriate, and it calculates and displays the near and far fields due to an excitation from a line source or a plane wave

Line Source Excitation of an Array of Circular Metamaterial Cylinders: Boundary Value Solution and Applications

A rigorous semi-analytical solution for electromagnetic scattering from an array of parallel circular cylinders of arbitrary radii and positions due to a line source excitation is developed. The cylinders can be any of three materials: metamaterial, dielectric, perfect electric conductor or a combination. Two different applications are presented here; the use of the characteristics of metamaterial to enhance the performance of corner reflector antennas, and the creation of a plane wave in the near field from an array of conducting cylinders excited by a line source.