Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
Browse
3 results
Search Results
Conference Object Citation - Scopus: 2Compact Proton Accelerator in Uhf Band at Kahvelab(JACoW Publishing, 2022) Esen, S.; Adıgüzel, A.; Koçer, O.; Çağlar, A.; Çelebi, E.; Öz, S.; Özcan, V.E.; Karatay, Anıl; Yaman, Fatih; Yılmaz, Hasan ÖnderProton Test Beam at KAHVELab (Kandilli Detector, Accelerator and Instrumentation Laboratory) project aims to design and produce a radio frequency quadrupole (RFQ) operating at 800 MHz in Istanbul, Turkey using the local resources. The beamline consists of a proton source, a low energy beam transport (LEBT) line including the beam diagnostic section and the RFQ cavity itself. This RFQ is 4-vane, 1-meter-long cavity to accelerate the 20 keV beam extracted from plasma ion source to 2 MeV. Its engineering prototype is already produced and subjected to mechanical, low power RF and vacuum tests. In this study, the results of the first test production, especially the bead-pull test setup will be discussed. © 2022 Proceedings - Linear Accelerator Conference, LINAC. All rights reserved.Article Citation - WoS: 3Citation - Scopus: 3Reconstructions of Effective Parameters for a Metamaterial Antenna Via 3d-Printed Components(Taylor & Francis, 2022) Yılmaz, Hasan Önder; Yaman, FatihThis study presents the reconstruction of effective medium parameters for a double negative metamaterial slab from the knowledge of the measured/simulated S-matrix. The structure initially has been designed to embed into a patch antenna for a radar application. To observe the medium characteristics, we locate the slab in a rectangular waveguide for various orientations. The waveguide-based retrieval method is applied to find parameters regarding the biaxial anisotropic medium. Fundamental mode is used for the excitation. Additive printing technology is employed to manufacture a rectangular waveguide and its adapters for the experiments. The metallization is achieved by coating the printed structures with conductive thin layers. Experimental setups for each orientation are simulated as well. We illustrate good agreements between simulation and measurements under the fabrication tolerances. The feasibility and applicability of the additive printing technology for the investigations of the metamaterial anisotropic/bianisotropic nature is reported.Article Citation - WoS: 34Citation - Scopus: 37Metamaterial antenna designs for a 5.8-GHz Doppler radar(IEEE, 2020) Yılmaz, Hasan Önder; Yaman, FatihThe aim of this paper is to investigate applicability and the effectiveness of the metamaterial-based antennas for a 5.8-GHz Doppler radar. Thus, a double negative index metamaterial structure is designed as a transmitter antenna and a near-zero index medium is integrated with a patch antenna for the receiver. Significant improvements in bandwidth for the transmitter, slight improvements in gain and in directivity for the receiver, and typically size reduction for both antennas are obtained. It is shown that return loss, radiation pattern, and gain measurement results of the newly designed antennas agree well with the simulations for a desired frequency band. The last part of the study is devoted to express the adaptation of the antennas for a low-power radar system whose aim is to reconstruct the velocity of the human, indoor as well as behind the wall, from the shift in the received frequency. The accuracy of the velocity measurements and field test results of the radar with the metamaterial antennas are reported.