Electromagnetic Scattering from Obstacles in the Near Field Region of Electrically Large Arrays

Cetin, Ramazan
Aydın Çivi, Hatice Özlem
Nepa, Paolo
Manara, Giuliano
In this paper, an efficient method for the analysis of electromagnetic scattering/radiation from the obstacles nearby electrically large array antennas, with nonuniform excitation, is proposed. The approach is based on the combination of a ray field representation of electrically large arrays and a DFT (Discrete Fourier Transform) based representation of array current distribution. Proposed method is applied to a 2D problem: Radiation of a linear array of 2N+1 infinitely long current elements with tapered current distribution in the presence of an infinitely long PEC (Perfect Electric Conductor) cylinder. Accuracy and efficiency of the method is discussed by numerical examples.


Efficient analysis of phased arrays of microstrip patches using a hybrid generalized forward backward method/Green's function technique with a DFT based acceleration algorithm
Bakir, Onur; Aydın Çivi, Hatice Özlem; Erturk, Vakur B.; Chou, Hsi-Tseng (Institute of Electrical and Electronics Engineers (IEEE), 2008-6)
A hybrid method based on the combination of generalized forward backward method (GFBM) and Green's function for the grounded dielectric slab together with the acceleration of the combination via a discrete Fourier transform (DFT) based algorithm is developed for the efficient and accurate analysis of electromagnetic radiation/scattering from electrically large, irregularly contoured two-dimensional arrays consisting of finite number of probe-fed microstrip patches. In this method, unknown current coefficien...
Assessment of alternative simulation techniques in nonlinear time history analyses of multi-story frame buildings: A case study
Karim Zadeh Naghshineh, Shaghayegh; Askan Gündoğan, Ayşegül; Yakut, Ahmet (2017-07-01)
In regions with sparse ground motion data, simulations provide alternative acceleration time series for evaluation of the dynamic response of a structure. Different ground motion simulation methods provide varying levels of goodness of fit between observed and synthetic data. Before using the seismologically acceptable synthetic records for engineering purposes, it is critical to investigate the efficiency of synthetics in predicting observed seismic responses of structures. For this purpose, in this study ...
Applications of hybrid discrete Fourier transform-moment method to the fast analysis of large rectangular dipole arrays printed on a thin grounded dielectric substrate
Chou, HT; Ko, HK; Aydın Çivi, Hatice Özlem; ERTÜRK, VAKUR BEHÇET (2002-08-05)
Recently a discrete Fourier transform-method of moments (DFT-MoM) scheme was developed for fast analysis of electrically large rectangular planar dipole arrays, which has been shown to be very efficient in terms of number reduction of unknown variables and computational complexity. The applications of this DFT-MoM to treat dipole arrays printed on a grounded dielectric substrate are examined in this Letter. Numerical results are presented to validate its efficiency and accuracy. (C) 2002 Wiley Periodicals, ...
Analysis of the radiation from aparture/printed antennas in the presence of periodic structures through numerical and asymptotic techniques
Manara, Giuliano; Aydın Çivi, Hatice Özlem; Nepa, Paolo; Çetin, Ramazan(2010)
Proje kapsamında, yakınında saçıcıların bulunduğu elektriksel olarak büyük anten dizilerinin ışıma/saçınma problemini etkin bir şekilde analiz etmek için bir yöntem geliştirmek üzere çalışmalar yapılmıştır. Bu yöntem elektriksel olarak büyük dizilerin asimptotik ışın alan gösterimine ve dizi akımlarının Ayrık Fourier Dönüşüm ifadelerine dayanmaktadır. Gerçekçi anten dizilerinin üzerindeki akım dağılımının Ayrık Fourier Dönüşümünün, dizinin yakınında saçınmaya yol açabilecek nesneler olduğu durumda bile, bel...
Multiscale Modeling of Thin-Wire Coupling Problems Using Hybridization of Finite Element and Dipole Moment Methods and GPU Acceleration
ÖZGÜN, ÖZLEM; Mittra, Raj; Kuzuoğlu, Mustafa (2020-01-01)
In this article, a hybrid numerical method, called finite element method (FEM) + dipole moment (DM), is presented for efficient solution of multiscale electromagnetic radiation and scattering problems that involve structures with fine features, such as thin-wire antennas or objects. In this method, the FEM is hybridized with the DM approach to help ease certain computational burdens, such as mesh refinement, ill-conditioning, memory overload, and long computation times, when solving multiscale problems with...
Citation Formats
R. Cetin, H. Ö. Aydın Çivi, P. Nepa, and G. Manara, “Electromagnetic Scattering from Obstacles in the Near Field Region of Electrically Large Arrays,” 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/54233.