Metamalzeme tabanlı RF yansıtıcı özelliği arttırılmış boya ile frekans seçici yüzey tasarımı

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Thesis Type: Postgraduate

Institution Of The Thesis: Ataturk University, Fen Bilimleri Enstitüsü, Elektrik Elektronik Mühendisliği Anabilim Dalı, Turkey

Approval Date: 2025

Thesis Language: Turkish

Student: HAKAN KIZILTAŞ

Supervisor: Gökhan Öztürk

Open Archive Collection: AVESIS Open Access Collection

Abstract:

Purpose: The purpose of this thesis is to design a high-efficiency frequency selective surface (FSS) model using a ring-shaped geometry for applications such as electromagnetic interference (EMI) protection, radio frequency (RF) filtering, and frequency selective surface (FSS) systems. The design aims to achieve characteristics such as wide bandwidth, low reflection, high absorption capacity, and independence from the angle of incidence of electromagnetic waves. Method: During the design process, the design parameters of the ring-shaped FSS, such as unit cell size, dielectric layer thickness, conductive surface thickness, conductive surface radius, and conductive surface width, were examined to achieve an optimal design. The design and optimization were carried out using the CST Studio Suite 3D electromagnetic simulation software to improve electromagnetic performance. The frequency response, reflection, and absorption characteristics of the FSS were analyzed, and the parameter values that provide the best performance were determined. As a result of the design process, the ring-shaped FSS was produced using screen printing on textile materials with polyurethane-based paint. Findings: The performance parameters of the ring-shaped FSS designed as a result of the design studies can be summarized as follows: bandwidth: 1.75 GHz, maximum reflection frequency: 6.00 GHz, and maximum absorption value: -27.13 dB. These results demonstrate that the design has a highly efficient structure. The design exhibits a high absorption capacity for electromagnetic waves and a low reflection value. Additionally, it was determined that this FSS design shows a performance independent of the angle of incidence of incoming electromagnetic waves and exhibits the characteristics of a band-stop filter. This indicates that the FSS provides the same level of absorption for electromagnetic waves arriving from different angles. Results: In this thesis, a metamaterial-based FSS was designed and its electromagnetic performance was improved. As a result of optimization, it was observed that the FSS achieved the desired targets in terms of bandwidth, reflection, and absorption values. The wide bandwidth, high absorption capacity, and independence from the angle of incidence make this FSS suitable for use in various application areas, such as EMI protection, RF filtering, and radar systems. The design and optimization process presented in this thesis provides a new approach to the design of FSS.