Theoretical investigation of metamaterials: srr structures and periodic arrays of thin conducting wires

Download
2008
Ateş, Kazım Ozan
In recent years, there has been an increasing interest on left handed metamaterials because of their possible innovative applications. The pioneer study introducing such materials was brought out by V. G. Veselago in 1968 [1]. In his work, Veselago proposed a medium having simultaneously negative electric permittivity and magnetic permeability and investigated its electromagnetic characteristics. He found out that the electric field, magnetic field and the propagation vector form a left handed triplet, thus named such materials as “Left Handed Materials”. Despite the significance of Veselago’s inferences, the metamaterial theory stayed dormant for nearly 30 years. Towards the end of 1990s, the physically realizable left handed materials were built as the combination of two periodical structures; Split Ring Resonators (SRRs) and metallic thin wire arrays [4-5]. In this thesis, electrical and magnetic characteristics of the left handed metamaterials are theoretically investigated by using the analytical models for their permittivity and permeability functions with respect to frequency. For this purpose, first, two basic metamaterial structures; the Split Ring Resonators and Thin Metallic Wire Arrays are studied individually and their electrical and magnetic characteristics are examined. Finally, the composite left handed structure containing both SRRs and thin wires is studied to investigate the resulting simultaneous resonance properties and to estimate their overall effective permeability and permittivity functions.

Suggestions

Control electronics for mems gyroscopes and its implementation in a CMOS technology
Eminoğlu, Burak; Akın, Tayfun; Department of Electrical and Electronics Engineering (2011)
This thesis, for the first time in literature, introduces a comprehensive study about analog controller designs for MEMS vibratory gyroscopes. A controller of a MEMS gyroscope is mandatory for robust operation, which is insensitive to sensor parameters and ambient con- ditions. Errors in the controller design not only deteriorate transient performance, such as settling time and overshoot, but also cause performance degradation due to stability problems. Accordingly, true controller design for a gyroscope is...
Computation of radar cross sections of complex targets by shooting and bouncing ray method
Özgün, Salim; Kuzuoğlu, Mustafa; Department of Electrical and Electronics Engineering (2009)
In this study, a MATLAB® code based on the Shooting and Bouncing Ray (SBR) algorithm is developed to compute the Radar Cross Section (RCS) of complex targets. SBR is based on ray tracing and combine Geometric Optics (GO) and Physical Optics (PO) approaches to compute the RCS of arbitrary scatterers. The presented algorithm is examined in two parts; the first part addresses a new aperture selection strategy named as “conformal aperture”, which is proposed and formulated to increase the performance of the cod...
RF coil system design for MRI applications inhomogeneous main magnetic field
Yılmaz, Ayhan Ozan; Aşkar, Murat; Department of Electrical and Electronics Engineering (2007)
In this study, RF coil geometries are designed for MRI applications using inhomogeneous main magnetic fields. The current density distributions that can produce the desired RF magnetic field characteristics are obtained on predefined cubic, cylindrical and planar surfaces and Tikhonov, CGLS, TSVD and Rutisbauer regularization methods are applied to match the desired and generated magnetic fields. The conductor paths, which can produce the current density distribution calculated for each surface selection an...
3D hand tracking in video sequences
Tokatlı, Aykut; Halıcı, Uğur; Department of Electrical and Electronics Engineering (2005)
The use of hand gestures provides an attractive alternative to cumbersome interface devices such as keyboard, mouse, joystick, etc. Hand tracking has a great potential as a tool for better human-computer interaction by means of communication in a more natural and articulate way. This has motivated a very active research area concerned with computer vision-based analysis and interpretation of hand gestures and hand tracking. In this study, a real-time hand tracking system is developed. Mainly, it is image-ba...
Processing and characterization of carbon nanotube based conductive polymer composites
Yeşil, Sertan; Bayram, Göknur; Department of Chemical Engineering (2010)
The aim of this study was to improve the mechanical and electrical properties of conductive polymer composites. For this purpose, different studies were performed in this dissertation. In order to investigate the effects of the carbon nanotube (CNT) surface treatment on the morphology, electrical and mechanical properties of the composites, poly(ethylene terephthalate) (PET) based conductive polymer composites were prepared by using as-received, purified and modified carbon nanotubes in a twin screw extrude...
Citation Formats
K. O. Ateş, “Theoretical investigation of metamaterials: srr structures and periodic arrays of thin conducting wires,” M.S. - Master of Science, Middle East Technical University, 2008.