Frequency selective surfaces with rectangular patches.

Öztürk, İlhan


Frequency invariant beamforming and its application to wideband direction of arrival estimation
Babataş, Eren; Candan, Çağatay; Department of Electrical and Electronics Engineering (2008)
In this thesis the direction of arrival estimation of wideband signals using frequency invariant beamforming method is examined. The difficulty with the direction of arrival estimation of wideband signals is that it is not possible to obtain a single covariance matrix valid for the whole frequency spectrum of the signal. There are various methods proposed in the literature to overcome this difficulty. The common aim of all the methods is to obtain a composite covariance matrix for the overall band of the si...
Frequency response function measurement and parametric SISO system modelling of a gyro-stabilized infrared electro optic gimbal system
Ozdogan, Gokhan; Leblebicioğlu, Mehmet Kemal (2016-05-01)
In this research study, a single axis (inner azimuth gimbal) of a four-axis gyro-stabilized electro optic gimbal system is modelled through experimental investigation in the frequency domain, and the results of this investigation are presented. The dynamic behaviour of the mechanical system is obtained from input and output signals, strictly speaking, nonparametric measurements. Detecting and measuring the nonlinear distortions allows a better understanding and gives an intuitive insight into the error sour...
Frequency domain non-linear modelling and analysis of liquid filled column dampers
Kızılay, Hazım Sefa; Ciğeroğlu, Ender (Springer, Cham; 2019-02-20)
Tuned liquid column dampers (TLCDs) have an extensive usage as an effective vibration absorber to enhance the structure response under the effect of seismic or wind loads. In this study, parameter optimization of nonlinear model of a TLCD in frequency domain under harmonic excitation is proposed in order to improve performance of TLCDs. The non-linearity in the model is due to the head-loss caused by the orifice resulting in velocity squared damping. A 6-story building with a TLCD is considered as a case st...
Frequency Selective Characteristics of a Plasma Layer with Sinusoidally Varying Electron Density Profile
GÜREL, ÇİĞDEM SEÇKİN; Oencue, Emrah (Springer Science and Business Media LLC, 2009-06-01)
In this study reflection, absorbtion and transmission characteristics of a plasma layer having sinusoidally varying electron number density are analysed. In the analysis, plasma layer is divided into thin subslabs with constant electron number densities. The general frequency selective behavior of the plasma is investigated by varying the plasma parameters, external magnetic field excitation and sinusoidal electron distribution in order to be used in recent plasma applications.
Frequency modulated pulsed stimulation in optically stimulated luminescence
Bulur, Enver; Murray, A.S. (2001-01-01)
A new pulsed-OSL stimulation unit capable of producing stimulation pulses down to 4 us wide has been developed. A matrix of 49 light emitting diodes (LEDs) are pulsed using a voltage-to-frequency converter, which produces fixed width pulses of adjustable duty cycle in the frequency range 0-10 kHz. Since the average light power falling on a sample is proportional to the repetition rate of the pulses, we have used voltage control of the frequency to undertake linearly modulated optically stimulated luminescen...
Citation Formats
İ. Öztürk, “Frequency selective surfaces with rectangular patches.,” Middle East Technical University, 1993.