Characteristic Mode Analysis of Unit Cells of Metal-Only Infinite Arrays

Characteristic mode analysis of metal only unit cells of periodic structures is performed using Method of Moments based formulation. Ewald's transformation is incorporated for a fast and cost efficient solution and the advantages over spatial Green's function are discussed. The influence of the unit cell size on the characteristic modes is demonstrated. Various metal-only reflectarray elements are compared and their radiation characteristics are interpreted using the theory of characteristic modes. It is shown that characteristic modes of the unit cell can help us to understand the radiation and scattering behavior of the unit cell and this physical insight can be used in periodic array unit cell design.
Advanced Electromagnetics


Characteristic Mode Analysis of Reflectarray Unit Cell
Haykır, Yiğit; Aydın Çivi, Hatice Özlem (2018-12-10)
In this work, characteristic mode analysis for unit cells of metal-only periodic structures such as reflectarrays, transmitarrays and frequency selective surfaces (FSS) is presented. Ewald’s representation of three dimensional (3-D) Green’s function for two dimensional (2-D) periodicity is utilized within the Method of Moment (MoM) analysis. Modal characteristics of reflectarray antennas are investigated. Relation between characteristic modes and the reflection coefficients for reflectarray antennas is disc...
Time-resolved optically stimulated luminescence (osl) studies on samples containing quartz and feldspar
Yeltik, Aydan; Bulur, Enver; Department of Physics (2009)
Time Resolved OSL (TR-OSL) is a technique to record the luminescence decay curve data after a brief stimulation pulse and can possibly be used for the separation of luminescence signals from quartz and feldspars. In this study luminescence emission from quartz and feldspar samples was investigated. TR-OSL signals of these samples were studied for the variations with preheating and annealing temperature, stimulation pulse width and total stimulation time, optical bleaching, radiation dose and measurement tem...
Finite element modeling of scattering from objects in rectangular waveguides
Gülbaş, Hüseyin; Kuzuoğlu, Mustafa; Özlem, Özgün; Department of Electrical and Electronics Engineering (2017)
Numerical analysis of scattering parameters of split ring resonators which are one of the microwave circuit elements is performed by the Finite Element Method in this thesis. The fundamentals of the model and analysis method will be discussed firstly. Afterwards, the basics of Finite Element Method including weak variational form of the wave equation, 3D formulations and application to scattering parameters will be presented. The concepts of Perfectly Matched Layer and resonators will be examined in detail....
Tissue resistivity estimation in the presence of positional and geometrical uncertainties
Baysal, U; Eyüboğlu, Behçet Murat (2000-08-01)
Geometrical uncertainties (organ boundary variation and electrode position uncertainties) are the biggest sources of error in estimating electrical resistivity of tissues from body surface measurements. In this study, in order to decrease estimation errors, the statistically constrained minimum mean squared error estimation algorithm (MiMSEE) is constrained with a priori knowledge of the geometrical uncertainties in addition to the constraints based on geometry, resistivity range, linearization and instrume...
Data acquisition system for Lorentz force electrical impedance tomography using magnetic field measurements
Kaboutari, Keivan; Gençer, Nevzat Güneri; Department of Electrical and Electronics Engineering (2017)
Lorentz Force Electrical Impedance Tomography (LFEIT) is a novel imaging modality to image electrical conductivity properties of biological tissues. This modality is recently proposed for early stage diagnosis of cancerous tissues. The main aim of this thesis study is to develop a data acquisition system for LFEIT. Design of contactless receiver sensor, static magnetic field generation (0.56 T is generated by permanent neodymium magnets), amplification of received signals and experimental studies using vari...
Citation Formats
Y. Haykır and H. Ö. Aydın Çivi, “Characteristic Mode Analysis of Unit Cells of Metal-Only Infinite Arrays,” Advanced Electromagnetics, pp. 134–142, 2019, Accessed: 00, 2020. [Online]. Available: