Analysis and design of conformal frequency selective surfaces /

Download

index.pdf

Date

2014

Author

Dalkılıç, Akın

Metadata

Show full item record

Item Usage Stats

384
views

180
downloads

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 possessing periodicity, curved element arrangement and finite model conditions together. The model is finite in curved direction and infinite along the axis of the cylinder. Semi-finite model analysis is a powerful solution tool to determine both transmission and reflection responses of conformal FSS structures. With the introduced design methodology for conformal FSS implementations, a narrow band FSS radome operating in Ku-band and a wide band FSS model serving as a band-pass spatial filter for X-band (8.2-12.4 GHz) signals are designed. FSS performances are verified with both planar single element unit cell solutions and semi-finite analyses of curved and planar structures. Planar prototypes of narrowband FSS model are fabricated and measured. Reasons for discrepancies between simulated and measured filtering characteristics are investigated and explained.

Subject Keywords

Frequency selective surfaces., Radar cross sections., Radar

URI

http://etd.lib.metu.edu.tr/upload/12617344/index.pdf
https://hdl.handle.net/11511/23612

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Radar cross section analysis by shooting and bouncing rays method Çakır, Mustafa Kağan; Tokdemir, Turgut; Department of Engineering Sciences (2015) In this study, a MATLAB code incorporating `Shooting and Bouncing Rays (SBR) Method` is developed for calculating Radar Cross Section (RCS) of complex shapes. The code can calculate ray paths, magnetic current sheets, incident and scattered electric fields and RCS in horizontal, vertical and cross polarizations. While reflection effects are calculated by SBR algorithm, diffraction effects due to edges and corners are handled by `Equivalent Edge Currents (EEC’s)`. Wave frequency, aspect angle and number of r...
Radar propagation modelling using the split step parabolic equation method Türkboyları, Alpaslan; Koç, Seyit Sencer; Department of Electrical and Electronics Engineering (2004) This document describes radar propagation modelling using split step parabolic wave equation (PWE) method. A computer program using Fourier split-step (FSS) marching technique is developed for predicting the electromagnetic wave propagation in troposphere. The program allows specification of frequency, polarization, antenna radiation pattern, antenna altitude, elevation angle and terrain profile. Both staircase terrain modelling and conformal mapping are used to model the irregular terrain. Mixed Fourier tr...
Comparative evaluation of SAR image formation algorithms Şahin, Halil İbrahim; Dural Ünver, Mevlüde Gülbin; Koç, Seyit Sencer; Department of Electrical and Electronics Engineering (2010) In the scope of this thesis, simulation-based analyses and comparative evaluation of Synthetic Aperture Radar (SAR) image formation techniques, namely Time Domain Correlation, Range Stacking, Range Doppler and Chirp Scaling algorithms, are presented. For this purpose, first, the fundamental concepts of SAR such as SAR geometry, resolution and signal properties are explained. A broadside SAR simulator that provides artificial raw data as an input to the algorithms is designed and implemented. Then, the mathe...
Prospects of FMCW-based frequency diverse array radar Cetiner, Ramazan; Cetintepe, Cagri; Demir, Şimşek; Hizal, Altunkan (2019-11-01) The linear frequency modulated (LFM) frequency modulated continuous wave (FMCW)-based frequency diverse array (FDA) radar concept is investigated in detail. The radar operates as a linear pulsed FMCW/FDA in the transmission (TX) mode while it operates as a pulsed FMCW/phased array (PA) in the receiving mode. The issues such as low signal-to-noise ratio (SNR) of FDA, the time-angle scanning and time-range ambiguities are studied. It is shown that the local instantaneous frequency bandwidth is much smaller th...
Monte Carlo analysis of the effects of the material and shape uncertainties on radar cross section by the finite difference time domain method Kazar, Ali Kemal; Kuzuoğlu, Mustafa; Özgün, Özlem; Department of Electrical and Electronics Engineering (2013) The aim of this research is to analyze the variations in Radar Cross Section (RCS) values of dielectric and conducting objects due to material and shape uncertainties by employing the Finite Difference Time Domain Method and the Monte Carlo approach in electromagnetic scattering problems. MATLAB codes are developed and validated to solve the electromagnetic scattering problem involving two and three dimensional arbitrarily-shaped objects. Basic principles of FDTD and its implementation in MATLAB are describ...

Citation Formats

A. Dalkılıç, “Analysis and design of conformal frequency selective surfaces /,” M.S. - Master of Science, Middle East Technical University, 2014.