Electromagnetic scattering analysis and design of sandwich type radomes

Şerefoğlu, Mehmet Murat
In this thesis work, importance of radome structures for antenna systems is emphasized. Structural and electromagnetic requirements of various types of radome structures are analyzed and specific properties are given. Electromagnetic scattering analysis of sandwich type radome seams has been done. Total antenna system far electromagnetic field expression, which is the combination of original antenna far electromagnetic field and the scattered electromagnetic field of the framework of the sandwich radome structure has been found and simulated. To enhance electromagnetic transparency of sandwich type radomes two sandwich radome design methods are proposed which are expressed as Geometrical Randomization and Tuning the Seams. Electromagnetic scattering level minimizations advanced by these design methods are presented with related simulations.


Fpga implementation of jointly operating channel estimator and parallelized decoder
Kılcıoğlu, Çağlar; Yılmaz, Ali Özgür; Department of Electrical and Electronics Engineering (2009)
In this thesis, implementation details of a joint channel estimator and parallelized decoder structure on an FPGA-based platform is considered. Turbo decoders are used for the decoding process in this structure. However, turbo decoders introduce large decoding latencies since they operate in an iterative manner. To overcome that problem, parallelization is applied to the turbo codes and the resulting parallel decodable turbo code (PDTC) structure is employed for coding. The performance of a PDTC decoder and...
Design and construction of reduced size planar spiral antenna in the 0.5-18 ghz frequency range
Yıldız, İnanç; Hızal, Altunkan; Department of Electrical and Electronics Engineering (2004)
In this thesis, theoretical and practical evaluation of usual spiral antenna is revised. Working principles of both types of planar spiral antennas as Equiangular and Archimedean are introduced. A predesigned microstrip tapered balun used for feeding section of a spiral antenna is simulated on Ansoft HFSS software. Successful simulation results are obtained and measurements of implemented balun structure are made by using an HP 8722 D vector network analyzer. Antenna measurement techniques used in this stud...
Interference suppression by using space-time adaptive processing for airborne radar
Eryiğit, Özgür; Yılmaz, Ali Özgür; Department of Electrical and Electronics Engineering (2008)
Space-Time Adaptive Processing (STAP) is an effective method in Ground Moving Target Indicator (GMTI) operation of airborne radars. Clutter suppression is the key to successful MTI operation. Airborne radars are different than the ground based ones in regard to clutter due to the displacement of the platform during operation. When STAP methods are to be investigated, one needs to have accurate signal models while evaluating performance. In this thesis, a comprehensive received signal model is developed firs...
Tunable frequency microstrip antennas by rf-mems technology
Erdil, Emre; Aydın Çivi, Hatice Özlem; Department of Electrical and Electronics Engineering (2005)
This thesis presents the design, fabrication, and measurement of tunable frequency microstrip antennas using RF MEMS (Microelectromechanical Systems) technology. The integration of RF MEMS components with radiators enable to implement tunable systems due to the adjustable characteristics of RF MEMS components. In the frame of this thesis, different types of structures have been investigated and designed. The first structure consists of a microstrip patch antenna which is loaded with a microstrip stub whose ...
The electrical characteristics of antennas in their operational environment
Afacan, Gönenç; Tuncay, Birand; Department of Electrical and Electronics Engineering (2007)
This thesis investigates the variations of electrical properties of linear antennas mounted on certain platforms, depending on the physical properties of that platform. In this respect, related basic antenna simulations, electromagnetic simulations from primitive to complex models of airframes, and scale model measurements were used. Firstly, electrical properties of monopoles at known environment were examined and basic analyses were performed via an electromagnetic simulation tool, named CST Microwave Stu...
Citation Formats
M. M. Şerefoğlu, “Electromagnetic scattering analysis and design of sandwich type radomes,” M.S. - Master of Science, Middle East Technical University, 2009.