Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2009
Tezin Dili: İngilizce
Öğrenci: Levent Şahin
Danışman: GÖNÜL SAYAN
Özet:Metamaterials attracted significant attention in recent years due to their potential to create novel devices that exhibit specific electromagnetic properties. In this thesis, we investigated transmission and propagation properties of novel metamaterial structures. Electromagnetic properties of metamaterials are characterized and the resonance mechanism of Split Ring Resonator (SRR) structure is investigated. Furthermore, a recent lefthanded metamaterial structure for microwave regime called Fishnet-type metamaterial is studied. We demonstrated the left-handed transmission and negative phase velocity in Fishnet Structures. Finally, we proposed and successfully demonstrated novel approaches that utilize the resonant behavior of SRR structures to enhance the transmission of electromagnetic waves through sub-wavelength apertures at microwave frequency regime. We investigated the transmission enhancement of electromagnetic waves through a sub-wavelength aperture by placing SRR structures in front of the aperture and also by changing the aperture shape as SRR-shaped apertures. The incident electromagnetic wave is effectively coupled to the sub-wavelength aperture causing a strong localization of electromagnetic field in the sub-wavelength aperture. Localized electromagnetic wave gives rise to enhanced transmission from a single sub-wavelength aperture. The proposed structures are designed, simulated, fabricated and measured. The simulations and experimental results are in good agreement and shows significant enhancement of electromagnetic wave transmission through sub-wavelength apertures by utilizing proposed novel structures. Radius (r) of the sub-wavelength aperture is approximately twenty times smaller than the incident wavelength (r/λ~0.05). This is the smallest aperture size to wavelength ratio in the contemporary literature according to our knowledge.