Development of multi-layered circuit analog radar absorbing structures

Download
2012
Yıldırım, Egemen
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.

Suggestions

Design and implementation of coupled inductor Cuk converter operating in continuous conduction mode
Ayhan, Mustafa Tufan; Ersak, Aydın; Department of Electrical and Electronics Engineering (2011)
The study involves the following stages: First, coupled-inductor and integrated magnetic structure used in Cuk converter circuit topologies are analyzed and the necessary information about these elements in circuit design is gathered. Also, benefits of using these magnetic elements are presented. Secondly; steady-state model, dynamic model and transfer functions of coupled-inductor Cuk converter topology are obtained via state-space averaging method. Third stage deals with determining the design criteria to...
Modeling and fabrication of electrostatically actuated diaphragms for on-chip valving of MEMS-compatible microfluidic systems
Atik, Ali Can; Ozkan, Metin Dundar; Ozgur, Ebru; Külah, Haluk; Yıldırım, Ender (IOP Publishing, 2020-11-01)
This paper presents an analytical model to estimate the actuation potential of an electrostatic parylene-C diaphragm, processed on a glass wafer using standard microelectromechanical systems (MEMS) process technology, and integrable to polydimethylsiloxane (PDMS) based lab-on-a-chip systems to construct a normally-closed microvalve for flow manipulation. The accurate estimation of the pull-in voltage of the diaphragm is critical to preserve the feasibility of integration. Thus, we introduced an analytical m...
Analysis of slot coupled microstrip patch antennas
Ballıkaya, Elif; Aydın Çivi, Hatice Özlem; Department of Electrical and Electronics Engineering (2007)
Method of Moments (MoM)/Green’s function formulation is developed for the analysis of electromagnetic radiation from planar rectangular microstrip antennas with different feeding techniques. Investigated structures are microstrip line fed patch antenna, proximity coupled patch antenna and slot coupled patch antenna. For all these structures equivalent problems are defined. Then, integral equations where currents are the unknowns are obtained from boundary conditions and by using spectral domain representati...
Analysis and design of conformal frequency selective surfaces /
Dalkılıç, Akın; Alatan, Lale; Department of Electrical and Electronics Engineering (2014)
An efficient analysis and design approach for conformal frequency selective surface (FSS) structures is developed. The design methodology involves the analysis of both the planar and curved FSS structures. First, planar unit cell analysis of conformal FSS models are accomplished for normal and oblique incidence cases. To prove conformal applicability of planar designs, a semi-finite analysis method is utilized. This method is based on solution of a singly periodic curved FSS structure of semi-cylinder shape...
Design of a tubular switched reluctance linear generator for wave energy conversion based on ocean wave parameters
Mendes, R. P. G.; Calado, M. R. A.; Mariano, S. J. P. S.; Cabrita, C. M. P. (2011-09-10)
This work presents a procedure for the design and analysis of a linear tubular switched reluctance generator for wave energy conversion. The generator is meant to be applied to a direct drive wave energy converter, namely a point absorber. The device is modeled according to wave climate conditions at Esposende site in the Portuguese coast. The procedure starts with statistical analysis of the local random ocean behavior in order to determine most likely values of occurrence for the wave parameters in questi...
Citation Formats
E. Yıldırım, “Development of multi-layered circuit analog radar absorbing structures,” M.S. - Master of Science, Middle East Technical University, 2012.