Design and realization of a broad band antenna loaded with a metamaterial-inspired lens for subsurface microwave imaging applications

Download
index.pdf
2019
Yeşilyurt, Ömer
Show full item record
468
views
204
downloads
Ultra-wideband antennas are critical sensors for microwave imaging. In this work, radiation performance of an antipodal Vivaldi antenna is enhanced by using a broadband metasurface lens structure in 1-6 GHz bandwidth. Radiation pattern for the lens integrated antenna is more directive due to electromagnetic properties of the metasurface lens. In order to create such a lens, electrically responsive metamaterial unit cells with high effective permittivity values are designed. As we want to obtain a broadband antenna performance, metamaterial unit cell dimensions are adjusted to avoid the resonance regions of the metasurface over the desired operation bandwidth of the antenna. Overall lens structure is etched over the same substrate containing the antipodal Vivaldi antenna resulting in a compact design. Far-field radiation patterns indicate that more directive beam is radiated from the antenna with metasurface lens. Measurement and simulation results show that directivity is increased considerably without affecting the efficiency characteristics of the antenna. Microwave image of a shallowly buried conducting object is constructed by using with metasurface integrated antenna and also by using the conventional antipodal Vivaldi antenna as sensors. Two-dimensional microwave images are constructed by using the total energy values of the time signals measured at each spatial sampling point. Due to its more directive radiation pattern, the images obtained by the antenna with metasurface lens are observed to have better resolution.
Antennas (Electronics)., Microwave lenses., Lens antennas.
http://etd.lib.metu.edu.tr/upload/12623151/index.pdf
https://hdl.handle.net/11511/28073
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Implementation of a perfect metamaterial absorber into multi-functional sensor applications
AKGÖL, OĞUZHAN; KARAASLAN, MUHARREM; ÜNAL, EMİN; Sabah, C. (2017-05-30)
Perfect metamaterial absorber (MA)-based sensor applications are presented and investigated tigated in the microwave frequency range. It is also experimentally analyzed and tested to verify the behavior of the MA. Suggested perfect MA -based sensor has a simple configuration which introduces flexibility to sense the dielectric properties of a material and the pressure of the medium. The investigated applications include pressure and density sensing. Besides, numerical simulations verify that the suggested s...
Development of K band microstrip patch antenna array for traffic radars
Aydemir, Aslı Eda; Aydın Çivi, Hatice Özlem; Department of Electrical and Electronics Engineering (2017)
In this thesis work, two microstrip patch antenna arrays are designed for the traffic radar applications. Both of them operate at the 24.125 GHz with 250 MHz bandwidth. Two different series feed networks are used, namely shunt connected series feed network and in line coupled series feed network. The one with shunt connected series feed network is manufactured and measured to make comparisons with the simulation results. It is observed that simulation and measurement results are very similar. 7 degree beamw...
Analysis of spherical-rectangular printed antennas and antenna arrays using cavity model
Demir, Oğuz; Dural Ünver, Mevlüde Gülbin; Department of Electrical and Electronics Engineering (2017)
Printed antennas are commonly used since these antennas are preferred in many applications due to their advantageous properties. In order to employ these antennas in such applications, a thorough investigation and analysis are generally required. Although this can be implemented with fully numerical methods for the sake of high accuracy, the complex calculations required in the process lead to heavy computational load, hence generally demands high quality simulation software. In this thesis, the spherical-r...
Analysis of dual - polarized aperture - coupled microstrip antennas with H-shaped slots and equivalent circuit modeling of H shaped slots
İşeri, Kadir; Alatan, Lale; Department of Electrical and Electronics Engineering (2012)
This thesis includes the design, production and measurement of a wideband dualpolarized X-band aperture-coupled microstrip patch antenna. The wideband and dual-polarized operation is achieved through the use of H-shaped coupling slots. Therefore, the equivalent circuit modeling of a microstrip line fed H-shaped slot is also studied in this thesis. A step-by-step procedure is followed during the design process of the dual-polarized aperture-coupled microstrip antenna. First, an aperture-coupled microstrip an...
Analysis and design of passive microwave and optical devices using the multimode interference technique
Sunay, Ahmet Sertaç; Birand, Mehmet Tuncay; Department of Electrical and Electronics Engineering (2005)
The Multimode Interference (MMI) mechanism is a powerful toool used in the analysis and design of a certain class of optical, microwave and millimeter wave devices. The principles of the MMI method and the self-imaging principle is described. Using this method, NXM MMI couplers, MMI splitter/combiners are analyzed. Computer simulations for illustrating the "Multimode Interference Mechanism" are carried out. The MMI approach is used to analyze overmoded 'rectangular metallic' and 'dielectric slab' type of wa...
Citation Formats
Ö. Yeşilyurt, “Design and realization of a broad band antenna loaded with a metamaterial-inspired lens for subsurface microwave imaging applications,” M.S. - Master of Science, Middle East Technical University, 2019.
METU IIS - Integrated Information Service open@metu.edu.tr