Browsing by Subject "Method of analytical regularization"

Now showing 1 - 7 of 7

Open Access
Analysis of an arbitrary conic section profile and thin dielectric cylindrical reflector illuminated by an E-polarized complex source point beam
(IEEE, 2012) Oǧuzer, T.; Kuyucuoǧlu F.; Avgin I.; Altıntaş, Ayhan
We simulated arbitrary conic section profile and thin layer dielectric reflector using the Method of Analytical Regularization (MAR) techniques. The reflector is assumed to be illuminated by a complex source point type feed antenna in E-polarization mode. We obtained excellent accuracy and convergence of our simulation. © 2012 IEEE.
Open Access
Analysis of an arbitrary-profile, cylindrical, impedance reflector surface illuminated by an E-polarized complex line source beam
(VSP BV, 2014) Kuyucuoglu, F.; Oǧuzer, T.; Avgin, I.; Altintas, A.
Electromagnetic scattering from a cylindrical reflector surface having an arbitrary conic section profile is studied. We assumed an electrically thin layer antenna illuminated by a complex line source in E-polarization mode. Our boundary value formulation, without loss of generality, involves an integral equation approach having impedance-type thin-layer boundary conditions. For simplicity, we also considered both faces of the reflector of the same uniform impedance value. Our computation employs the Method of Analytical Regularization (MAR) technique: the integral equations are converted into the discrete Fourier transform domain yielding two coupled dual series equations, which are then solved by the Fourier inversion and Riemann Hilbert Problem techniques. We demonstrate the accuracy and the convergence behaviors of our numerically solved MAR results that can serve as an accurate benchmark for comparison with widely used results obtained by approximate boundary conditions. © 2013 Taylor and Francis.
Open Access
Analysis of the elliptic-profile cylindrical reflector with a non-uniform resistivity using the complex source and dual-series approach: H-polarization case
(Springer, 2013) Oğuzer, T.; Altintaş, A.; Nosich, A. I.
An elliptic-profile reflector with varying resistivity is analyzed under the illumination by an H-polarized beam generated by a complex-source-point (CSP) feed. The emphasis is done on the focusing ability that is potentially important in the applications in the optical range related to the partially transparent mirrors. We formulate the corresponding electromagnetic boundary-value problem and derive a singular integral equation from the resistive-surface boundary conditions. This equation is treated with the aid of the regularization technique called Riemann Hilbert Problem approach, which inverts the stronger singular part analytically, and converted to an infinite-matrix equation of the Fredholm 2nd kind. The resulting numerical algorithm has guaranteed convergence. This type of solution provides more accurate and faster results compared to the known method of moments. In the computations, a CSP feed is placed into a more distant geometrical focus of the elliptic reflector, and the near-field values at the closer focus are plotted and discussed. Various far-field radiation patterns including those for the non-uniform resistive variation on the reflector are also presented.
Open Access
Effect of the off-focus shift of the feed on the radiation characteristics of a 2-D parabolic reflector antenna
(IEEE, 2010) Oğuzer, T.; Altıntaş, A.; Nosich, Alexander
The parabolic reflector antennas are widely used in the telecommunication systems and generally have large aperture sizes like 50λ to 80λ and larger. Their reliable full-wave analysis with the conventional Method of Moments (MoM) or with the other numerical methods is difficult because of inaccessible speed and accuracy. This statement is valid both for 3D and 2D reflector antennas in both polarizations. The Method of Analytical Regularization (MAR) constitutes an alternative solution compared to the ordinary MoM, which can provide only 1-2 digit accuracy. It provides finer accuracy within a reasonable computation time because the computational error can be decreased simply by increasing the matrix size in MAR. We have previously developed this method for the accurate simulation of the arbitrary conical section profile 2D reflector antennas, and the corresponding codes have provided us with accurate benchmark data. Here we study a similar problem however with the feed simulated by Complex Source Point (CSP) source located at an off-focus point on the symmetry axis of a front-fed reflector antenna. The numerical results are presented for the radiation characteristics including the forward and backward directivities and the radiation patterns in all directions. © 2010 IEEE.
Open Access
Focusing of THz waves with a microsize parabolic reflector made of graphene in the free space
(Springer International Publishing, 2017) Oguzer T.; Altintas, A.; Nosich A.I.
Background: The scattering of H- and E-polarized plane waves by a two-dimensional (2-D) parabolic reflector made of graphene and placed in the free space is studied numerically. Methods: To obtain accurate results we use the Method of Analytical Regularization. Results: The total scattering cross-section and the absorption cross-section are computed, together with the field magnitude in the geometrical focus of reflector. The surface plasmon resonances are observed in the H-case. The focusing ability of the reflector is studied in dependence of graphene’s chemical potential, frequency, and reflector’s depth. Conclusions: It is found that there exists an optimal range of frequencies where the focusing ability reaches maximum values. The reason is the quick degradation of graphene’s surface conductivity with frequency. © 2017, The Author(s).
Open Access
The method of analytical regularization in the electromagnetic wave scattering by thin disks
(Institution of Engineering and Technology, 2007) Balaban, M. V.; Nosich, A. I.; Altıntaş, Ayhan; Benson, T. M.
We consider the problem of diffraction of an arbitrary electromagnetic wave by a thin disk made from different materials and located in free space. Here we imply a zero- thickness perfectly electrically conducting (PEC) disk, and also thin electrically resistive (ER) and dielectric disks whose thickness is much smaller than the disk radius and the free space wavelength, and also much smaller than the skin-layer depth in the ER disk case. The method used for the modeling is based on the integral equation (IE) technique and analytical regularization. Starting with Maxwell's equations, boundary conditions and the radiation condition at infinity we obtain a set of coupled dual IEs (DIEs) for the unknowns and then reduce this set of equations to the coupled IEs of the Fredholm second kind. To verify our results we calculate the far field characteristics in the case of the PEC disk with the incident field being the field of horizontal electrical dipole located on the disk axis.
Open Access
Scattering and absorption performance of a microsize graphene-based parabolic reflector in the THz range illuminated by a complex line source
(IEEE, 2017) Oğuzer, T.; Altıntaş, Ayhan
The scattering and absorption characteristics of a two- dimensional (2-D) parabolic reflector made of graphene and placed in the free space is simulated using the Method of Analytical Regularization (MAR) technique. Reflector is illuminated by a complex magnetic line source having a directive beam-like antenna pattern and placed in the geometrical focus of reflector. The total absorbed power and forward and backward directivities are computed. The surface plasmon (SP) resonances are observed. Besides, the scattering performance of the reflector is studied in dependence of the chemical potential of the graphene.