Development of multi-layered circuit analog radar absorbing structures

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2012

Öğrenci: EGEMEN YILDIRIM

Danışman: HATİCE ÖZLEM AYDIN ÇİVİ

Özet:

A fast and efficient method for the design of multi-layered circuit analog absorbing structures is developed. The method is based on optimization of specular reflection coefficient of a multi-layered absorbing structure comprising of lossy FSS layers by using Genetic Algorithm and circuit equivalent models of FSS layers. With the introduced method, two illustrative absorbing structures are designed with -15 dB reflectivity for normal incidence case in the frequency bands of 10-31 GHz and 5-46 GHz, respectively. To the author’s knowledge, designed absorbers are superior in terms of frequency bandwidth to similar studies conducted so far in the literature. For broadband scattering characterization of periodic structures, numerical codes are developed. The introduced method is improved with the employment of developed FDTD codes to the proposed method. By taking the limitations regarding production facilities into consideration, a five-layered circuit analog absorber is designed and manufactured. It is shown that the manufactured structure is capable of 15 dB reflectivity minimization in a frequency band of 3.2-12 GHz for normal incidence case with an overall thickness of 14.2 mm.