Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/11
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Conference Object Citation - WoS: 1Distance Measurement by Means of a Groove Guide Oscillator(Electromagnetics Academy, 2009) Bechteler, Thomas F.; Aydınlık Bechteler, Ayşe SevinçIn this work, a system for measuring the distance between two metallic plates is presented. A groove guide resonator operating in the X-band with an incorporated Gunn element serves as the distance sensor. According to the distance between the two metallic plates, the resonant frequencies of the groove guide oscillator change. In a first step, the fundamental resonant frequency of the groove guide oscillator at various distances is computed by means of the FDTD (Finite Difference Time Domain) method. In a second step, the resonant frequencies of the realized groove guide oscillator were measured. Although the signal's wavelength is about 30 mm, the resolution of the measurement is in the sub-millimeter level, i.e., about 25 mu m. Furthermore, in case of distance variations, even within a short time, the system is able to track distance variations nearly instantaneously. The resonant frequency information is processed using a heterodyne system.Article Citation - WoS: 2Citation - Scopus: 2The Groove-Guide Oscillator(Institute of Electrical and Electronics Engineers Inc., 2011) Bechteler, Thomas F.; Aydınlık Bechteler, Ayşe SevinçThe groove guide, a low-loss waveguide consists of two separate parallel plates whose separation distance can be adjusted, thereby affecting the frequency of operation of the guide itself. The standing waves in a groove guide along the direction of propagation are commonly obtained by either total reflection at both ends or by forming a closed loop. A negative resistance has to be implemented to induce oscillations of the groove guide resonator. It is desirable to induce oscillations directly inside the groove region therefore the negative resistance must be placed inside the groove. A Gunn element was selected to provide this negative resistance. A standard heterodyne system may be realized in order to use the groove-guide oscillator for distance or permittivity measurements. The groove-guide oscillator works as an active sensor in the X-band. The accuracy with which the resonant frequency is determined depends on the bias stability of the Gunn element, the phase noise of the local oscillator, and the error of the frequency counter.Article Citation - WoS: 2Citation - Scopus: 1Design of Coupling Structures for Groove Guide Resonators(John Wiley and Sons Inc., 2008) Bechteler, Thomas F.; Kuştepeli, Alp; Aydınlık Bechteler, Ayşe SevinçThree different coupling structures for a groove guide resonator operating at 10 GHz are investigated. First, propagatable modes are determined analytically. Then, the efficiency of the coupling structures is investigated by means of the method of moments and measurements. Finally, a groove guide resonator is designed and the resonance spectrum for each coupling structure is computed numerically, applying the finite-difference time-domain method. Numerical results are compared with experimental measurements. There is good agreement between the measured and simulated data.Article Citation - WoS: 3Citation - Scopus: 3Switchless Bidirectional Amplifier for Wireless Communication Systems(John Wiley and Sons Inc., 2007) Aydınlık Bechteler, Ayşe Sevinç; Bechteler, Thomas F.A bidirectional amplifier working at 2.4 GHz is presented in this article. The presented amplifier is able to amplify two signals simultaneously. This, since commonly used radio frequency switches are replaced by circulators. The amplifier is designed on a single small-sized printed circuit board. First, the new amplifier circuit is proposed and characterized. Then, its advantages and design problems are analyzed. Finally, design instructions are setup in order to obtain a good performance of the switchless amplifier within the frequency band of interest.Article Citation - WoS: 3Citation - Scopus: 2Analysis of Excitations for a Groove Guide Resonator at 10 Ghz by Means of the Fdtd Method(Springer Verlag, 2005) Bechteler, Thomas F.Various excitations of a new groove guide resonator working in the X-band (8 GHz - 12 GHz) are investigated by means of numerical simulations. For the numerical simulations the Finite-Difference Time-Domain method is used. The groove guide resonator, modelled both with and without excitation structures, is discretised in space. The results in the time domain are then transformed into the frequency domain in order to obtain the resonance frequency spectrum. Comparison between simulations with and without excitations shows the effect of the excitations on the resonance frequency spectrum. The results are compared with those of previous analytical methods.