WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7150
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Conference Object An Electromagnetic Target Classification Method for the Target Sets With Alien Target: Application To Small-Scale Aircraft Targets(Electromagnetics Academy, 2010) Seçmen, Mustafa; Turhan-Sayan, Gönül; 01. Izmir Institute of TechnologyThe electromagnetic target classification is a challenging problem since the scattered field from a target is highly dependent on operating frequency, polarization and aspect angle. In order to minimize adverse effects of these dependencies an intelligent classifier containing some distinguishable target features is needed. In addition, in order to be suitable for real target applications, the properties of operating with moderate frequency bandwidth and discriminating an alien target from a target set containing friend targets are important. In this study, an electromagnetic target classification method for isolated targets using noisy data in the classifier design to obtain high accuracy performance in a wider SNR range and having the ability of discrimination of an alien target without any priori information is introduced. The proposed method is mainly based on a late-time resonance region target classification technique, which was reported recently to use the multiple signal classification (MUSIC) algorithm and natural-resonance mechanism modeled by singularity expansion method (SEM) for target feature extraction, and modified for target sets containing alien target(s). The proposed classifier design method is demonstrated and tested for a target set of five friend and one alien small-scale aircraft targets. According to the test result, the proposed method gives high accuracy rates for this target set.Article Citation - WoS: 7Citation - Scopus: 8Compact Wideband Tapered-Fed Printed Bow-Tie Antenna With Rectangular Edge Extension(John Wiley and Sons Inc., 2019) Bozdağ, Göksenin; Seçmen, Mustafa; 01. Izmir Institute of TechnologyIn this article, a wideband printed bow-tie antenna is designed entire band of GPS (L5), PCS, IMT-2000, Bluetooth, Wi-Fi, WiMAX bands, and the most of frequency range of UWB. Apart from the traditional designs, the proposed antenna includes tapered printed line with a feeding point patch and triangular bows with rectangular edge extensions, which makes the antenna more compact. The antenna realized at the frequency band of 1.49-9.5 GHz (more than 6.3:1 ratio bandwidth) has the dimensions of 122mmx56mm (0.61(0)x0.28(0)). According to measurement results, the realized gain varies between almost 1 and 6.5 dBi with 4.44dBi average, which are in good agreement with simulation results. Radiation patterns at the lower frequencies of operating band show dipole like radiation pattern with higher cross-pol discrimination levels while they degrade at the higher frequencies due to increase in gain.Conference Object Citation - WoS: 1Citation - Scopus: 2Size-Reduced Printed Log Periodic Dipole Antenna With Single First Order Semi-Circle Iteration and Feed Point Patches(Institute of Electrical and Electronics Engineers Inc., 2018) Özgönül, Mehmet Can; Seçmen, Mustafa; 01. Izmir Institute of TechnologyThis paper presents the miniaturization and improvement of a printed log periodic dipole antenna (LPDA) by using patches at the feeding point and single first order semicircles. After the design of a conventional printed LPDA on FR4 substrate to cover L-band is performed, patches having 12 mm × 5 mm dimensions are placed to the feed point of the antenna. Although this modification gives same antenna size, it brings considerable increase in the return-loss bandwidth up to 2.25 GHz and higher gain values up to 2 GHz at the expense of decrease in gain at about 2.4 GHz. Afterwards, in order to reduce the total size of the antenna, single semicircles are substituted into the dipole arms, which results in 14% lateral size reduction. Besides, the bandwidth is further improved between 0.9 GHz and 2.4 GHz with better return loss performance, higher gain at 2.4 GHz and lower gain variation.Conference Object Citation - Scopus: 2Compact Printed Log Periodic Dipole Antenna With Second Order Semi-Circle Iteration(Institute of Electrical and Electronics Engineers Inc., 2018) Özgönül, Mehmet Can; Seçmen, Mustafa; Okuyucu, Serdar; 01. Izmir Institute of TechnologyIn this study, a size-reduced Log Periodic Dipole Antenna (LPDA) with second order semi-circle iteration is presented. Second order semi-circles are added to the dipole arms, which results in lateral size reduction of 23% and 8% with respect to standard LPDA and LPDA with first order semi-circle iteration, respectively. Measurement and simulation results demonstrate that the antenna has a wide range of operating frequency from 0.87 GHz to 2.55 GHz, and shows better gain variation than reference LPDAs.