Browsing by Subject "Parabolic antennas"

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Calculation of radome-enclosed aperture antenna in 3-D
(IEEE, 2010-09) Sukharevsky, I.; Altintas, Ayhan
The exact mathematical model of an aperture antenna and the image theory are used to develop exact and PO integral representations of the fields radiated by radome-enclosed aperture antenna. The desired problem is reduced to finding fields of a plane wave diffracted on the "symmetrized" radome. The passage of the wave through the wall of the radome is analysed by means of geometrical optics. Caustic influence is taken into account, and the contribution of stationary phase points of reflected field to the far-side radiation is discussed. Radiation patterns for antennas with a specified ampliphase distribution enclosed in spherical and parabolic radomes are analysed. © 2010 IEEE.
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
Radiation characteristics of a 2D parabolic reflector antenna excited by the H-polarized complex source
(IEEE, 2002-09) Oğuzer, T.; Nosich, A. I.; Altıntaş, Ayhan
The aim of this paper is to obtain accurate reference data for relatively large and realistic reflector antenna systems. We concentrate on a parabolic reflector antenna in the H-polarization case. The directive primary feed is modeled by the complex source point method and the relative accuracy of the results is verified. © 2002 IEEE.
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.
Open Access
Smart radome improves reflector antenna directivity
(IEEE, 1997) Altıntaş, Ayhan; Yurchenko, Viladimir; Nosich, A.
A numerical optimization procedure is applied to two dimensional model of cylindrical reflector antenna arbitrarily located inside a circular cylindrical dielectric radome. If the radome thickness has been optimized, then varying the radome radius and the reflector position has a small effect on the directivity. However, the feed position should be corrected with respect to the free-space optimum after finding the best thickness. The optimization code is based on solving an integral equation by means of the regularization technique, guaranteeing a desired accuracy.