Elektrik Elektronik Mühendisliği Bölümü

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Citation Count: Baykal, Yahya; Gokce, Muhsin C.; Ata, Yalcin, "Anisotropy effect on performance of subcarrier intensity modulated binary phase shift keying optical wireless communication links in weakly turbulent underwater channel", Journal of Modern Optics, (2019).
Anisotropy effect on performance of subcarrier intensity modulated binary phase shift keying optical wireless communication links in weakly turbulent underwater channel
(Taylor&Francis LTD, 2019) Baykal, Yahya; Gökçe, Muhsin Caner; Ata, Yalçın; 7812
The effect of the anisotropy on the bit-error-rate (BER) performance of subcarrier intensity modulated (SIM) binary phase shift keying (BPSK) optical wireless communication (OWC) links operating in weakly turbulent underwater channels is examined. BER variations versus the anisotropic factor are examined when the bandwidth, photodetector responsivity, load resistor and the underwater turbulence parameters are varied. As anisotropy in the underwater channel becomes larger, SIM BPSK OWC links have better BER performance at any link and turbulence parameter.
Citation Count: Demirkutlu, Eyyup; İskender, İres (2021). "Grid Connected Three-Phase Boost-Inverter for Solar PV Systems", International Journal of Renewable Energy Research, Vol. 11, No. 2, pp. 776-784.
Grid Connected Three-Phase Boost-Inverter for Solar PV Systems
(2021) Demirkutlu, Eyyup; İskender, İres; 133746
This paper presents a transformerless grid-connected three-phase boost-type inverter derived from the Swiss Rectifier (SR) and can be used in solar systems. The proposed boost-inverter retains the great advantages of the Swiss rectifier. Since the number of switches that are instantly switched with high frequency is only two, the switching losses are very low, therefore the proposed boost-inverter is very advantageous in terms of efficiency. Without having large transformer and electrolytic bus capacitors, the boost-inverter has an advantage in terms of size and weight. The switching states of the topology are given in detail. The operation principle of the boost-inverter is described with the help of equivalent circuits. A cascaded control method including current and voltage loops is designed. Simulation results are presented to validate the operation of the boost-inverter and show quality performance of the designed control approach. © 2021, International Journal of Renewable Energy Research. All Rights Reserved.
Citation Count: Gokce, Muhsin C...et.al., "Performance analysis of mimo fso systems with radial arraybeams and finite sized detectors" Laser Communication And Propagation Through The Atmosphere And Oceans III, Vol.9224, (2014).
Performance analysis of mimo fso systems with radial arraybeams and finite sized detectors
(Spie-Int Soc Optical Engineering, 2014) Gökçe, Muhsin Caner; Kamacıoğlu, Canan; Uysal, Murat; Baykal, Yahya
Multiple-input multiple-output (MIMO) systems are employed in free space optical (FSO) links to mitigate the degrading effects of atmospheric turbulence. In this paper, we consider a MIMO FSO system with practical transmitter and receiver configurations that consists of a radial laser array with Gaussian beams and finite sized detectors. We formulate the average received intensity and the power scinitillation as a function of the receiver coordinates in the presence of weak atmospheric turbulence by using the extended Huygens-Fresnel principle. Then, integrations over the finite sized multiple detectors are performed and the effect of the receiver aperture averaging is quantified. We further derive an outage probability expression of this MIMO system in the presence of turbulence-induced fading channels. Using the derived expressions, we demonstrate the effect of several practical system parameters such as the ring radius, the number of array beamlets, the source size, the link length, structure constant and the receiver aperture radius on the system performance.
Citation Count: Eyyuboğlu, Halil Tanyer; Hardalaç, Fırat, "Propagation of modified Bessel-Gaussian beams in turbulence" Optics and Laser Technology, Vol.42, No.2, pp.343-351, (2008).
Propagation of modified Bessel-Gaussian beams in turbulence
(Elsevier Science LTD, 2008) Eyyuboğlu, Halil T.; Hardalaç, Fırat; 7688
We investigate the propagation characteristics of modified Bessel-Gaussian beams traveling in a turbulent atmosphere. The source beam formulation comprises a Gaussian exponential and the summation of modified Bessel functions. Based on an extended Huygens-Fresnel principle, the receiver plane intensity is formulated and solved down to a double integral stage. Source beam illustrations show that modified Bessel-Gaussian beams, except the lowest order case, will have well-like shapes. Modified Bessel-Gaussian beams with summations will experience lobe slicing and will display more or less the same profile regardless of order content. After propagating in turbulent atmosphere, it is observed that a modified Bessel-Gaussian beam will transform into a Bessel-Gaussian beam. Furthermore it is seen that modified Bessel-Gaussian beams with different Bessel function combinations, but possessing nearly the same profile, will differentiate during propagation. Increasing turbulence strength is found to accelerate the beam transformation toward the eventual Gaussian shape.

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Browsing Elektrik Elektronik Mühendisliği Bölümü by Department "Çankaya Üniversitesi, Mühendislik Fakültesi, Elektronik ve Haberleşme Mühendisliği Bölümü"