Sener Uysal

Eastern Mediterranean University · Department of Electrical and Electronic Engineering

SAR generates high-resolution images irrespective of any weather condition and solar illumination. Feature-level fusion increases the dimensionally of feature space as well as feature redundancy brought by correlation among the features. In this paper, we propose a technique to select the most discriminative feature extraction techniques based on F...

In this paper, a new approach for improving the classification of different kinds of ground vehicles from moving stationary target acquisition and recognition images is proposed. Pseudo Zernike moments are used for feature extraction due to its capability of being scale, rotation, and translation invariant. To benefit from the diversities of region...

In this paper, a novel approach for selection of relevant features in SAR-ATR is proposed. The main concern of all studies in this filed is the accuracy. For this reason, many researchers have worked on feature extraction phase. Just a few studies focus on feature selection stage. The goal of working on feature selection is twofold. Firstly, the di...

In this paper, a novel approach for selection of relevant features in SAR-ATR is proposed. The main concern of all studies in this filed is the accuracy. For this reason, many researchers have worked on feature extraction phase. Just a few studies focus on feature selection stage. The goal of working on feature selection is twofold. Firstly, the di...

Entropy score is defined to be a metric indicating the class separation, which is then used in feature selection process to improve the moment-based classification performance of synthetic aperture radar (SAR) images. Feature extraction is performed over each SAR image by employing different moment methods to enrich the feature space before feature...

Clouds, being complex components of the atmosphere, have significant effects on power generation by photovoltaic (PV) systems. For example, shadows caused by the cloud coverage over a geographically distributed PV power plant may cause significant fluctuations in power generation by leaving a number of PV panels unable to generate power and contrib...

This paper proposes a simple and dynamic reconfiguration algorithm for photovoltaic (PV) arrays in order to mitigate negative effects of non-uniform spatial irradiance profiles on PV power production. Spatially dispersed irradiance profiles incident on inclined PV module surfaces at each application site are generated based on real sky images. Mode...

Network on Chip (NoC) has been suggested as an appropriate solution for the communication demands in Systems on Chip (SoCs). Due to the limitation of the resources in NoC, suitable load distribution over limited resources which is known as mapping problem is a challenging issue. This paper proposes a linearized model of quadratic assignment problem...

The development of a system for output power estimation and fault detection in photovoltaic (PV) modules using an artificial neural network (ANN) is presented. Over 30,000 healthy and faulty data sets containing per-minute measurements of PV module output power (W) and irradiance (W/m2) along with real-Time calculations of the Sun's position in the...

In this paper four feature extraction techniques are utilized to extract features from Synthetic Aperture Radar images namely as Radial Harmonic Fourier Moment, Local Binary Pattern, Haar Wavelet and Radon Transform. Holdout, 2-fold and 10-fold cross validation techniques are used for classification of images by using Support Vector Machine classif...

In this study, a new algorithm for classification of ground vehicles from standard synthetic aperture radar (SAR) images is proposed. Radial Chebyshev moment (RCM) is a discrete orthogonal moment that has distinctive advantages over other moments for feature extraction. Unlike invariant moments, its orthogonal basis leads to having minimum informat...

In this paper, four continuous moment-based feature extraction techniques for Synthetic Aperture Radar (SAR) images are examined. Geometric Moments (GMs), Legendre Moments (LMs), Zernike Moments (ZMs) and Pseudo Zernike Moments (PZMs) are introduced as a feature extraction for three types of ground vehicles from SAR images. GMs are simplest moment...

Objectives: To discover the impact of network parameters on power consumption in Networks on Chip (NoCs). Methods: Network on Chip (NoC) has been introduced as a solution for System on Chip (SoC) communication demands. Power consumption becomes a significant component in the NoCs due to the advanced VLSI technology. Findings: In this paper we compa...

This paper presents a comparative analysis of Levenberg-Marquardt (LM) and Bayesian Regularization (BR) backpropagation algorithms in development of different Artificial Neural Networks (ANNs) to estimate the output power of a Photovoltaic (PV) module. The proposed ANNs undergo training, validation and testing phases on 10000+ combinations of data...

Network on Chip (NoC) has been suggested as an appropriate and scalable solution for System on Chip (SoC) architectures having high communication demands. In this study, we propose heuristic fuzzy based mapping approaches to decrease the power consumption and improve the performance in the NoCs. The proposed method has two steps: core to task mappi...

Network on chip (NoC) has been proposed as an appropriate solution for today’s on-chip communication challenges. Power dissipation has become a key factor in the NoCs because of their shrinking sizes. In this paper, we propose a new encoding approach aimed at power reduction by decreasing the number of switching activities on the buses. This approa...

Network on Chip (NoC) is an appropriate and scalable solution for today’s System on Chips (SoCs) with the high communication demands. Application specific NoCs is preferable since they can be customized to optimize all requirements of the specific applications. This paper presents an OPtimization technique for Application specifIC NoCs (OPAIC), whi...

Structural Health Monitoring (SHM) plays an extremely substantial role in various structures in terms of collecting observation of environmental conditions as well as detecting failures. The present study demonstrates the algorithm for the process of SHM by applying integration of Radio Frequency Identification (RFID) system with sensor-tags in ord...

This paper mainly analyzes the performance of different photovoltaic array configurations under various shading patterns. A Matlab/Simulink based simulation model of a PV module is utilized as the smallest building block of the mentioned topologies. The model is validated using the datasheet parameters of the ‘SOLAREX MSX-60’ PV module. The perform...

This paper mainly focuses on the performance evaluation of "Perturb&Observe" and "Incremental Conductance" algorithms as the most commonly utilized two Maximum Power Point Tracking (MPPT) techniques for photovoltaic systems. Matlab/SIMULINK platform is used to model and simulate the entire system. The simulation model of a PV module is constructed...

This paper proposes a simple and practical simulation model for solar modules using MATLAB/Simulink. The model is based on a single-diode mathematical model of a solar cell and is capable of accurate modeling of I-V and P-V characteristics of a solar module. Model parameters are obtained from manufacturer's datasheets and series and shunt resistanc...

This paper mainly focuses on experimental performance analysis of solar modules under different irradiance values. Also effects of interconnection types and bypass diode application on module output characteristics under variable shading patterns are analyzed. The mentioned analyses are based on and supported by real-time measurement data and the r...

This paper proposes a simulation model for calculation of the sun`s position in the sky and the incidence angle of sunlight beams on the surface of solar modules with any tilt angle, located at any geographical location on the Earth`s surface. The electrical power generated by a solar panel directly depends on the amount of the received solar irrad...

This paper mainly focuses on methods of calculations of sun`s position in the sky and analyses of its effects on solar panel output characteristics collected during a case study. Methods for calculations of sun`s position in the sky and measurement of solar panel output characteristics are reviewed and then followed by a case study on an experiment...

This paper mainly focuses on the effects of variations of solar irradiance on PV panel power outputs and considers the importance of choosing the right orientation for system installations. The analyses are based on real-time measured data collected during a 6-Month period (October/2012-March/2013) in Northern Cyprus. The mentioned data presents th...

It is basically approved that the output power of a solar cell/module directly depends on the amount of solar irradiance which it receives from the sun. Also it is known that the irradiance values are not constant at any specific time interval. The changes in the position of the sun with respect to earth are one of the main reasons causing the vari...

The main purpose of this paper is on developing an intelligent system which provides real time monitoring and fault detection for solar panels. Utilizing artificial neural network technology, the solar panel fault detection system is capable of perceiving sun’s position in the sky and estimating the corresponding output power of a solar panel based...

The usage and deployment of Wireless Sensor Networks (WSN) is rapidly increasing in many different monitoring and control applications. In the majority of these applications, energy is a key factor in sensor networks since the sensor nodes are battery powered and hence have limited resources of energy. In this context, choosing a proper energy-effi...

Radio Frequency Identification (RFID) system is used for detecting and identifying the tagged objects by electromagnetic signals. Wireless Sensor Networks (WSN), which consists of a huge numbers of nodes, can monitor the condition of the environment including pressure, humidity, and temperature. Data is transferred via nodes to a certain location....

This paper has been withdrawn by the authors. In this paper, we propose a new low power coding technique by decreasing the number of switching activities on the buses which use transition signaling to transmit data. This approach dedicates the symbols with less ones to high probability data. MFLP unlike the most low power encoding does not rely on...

Based on the fact that energy can be transmitted using photons, light sources such as lasers can be used to transport power. Solar radiation is thus a promising means of satisfying future energy demands. Space Power Satellites (SPSs) were demonstrated forty years ago, but only recently has this approach become feasible. A fully optical SPS eliminat...

This paper presents a broadband bandpass amplifier in CMOS technology based on the cascaded single-stage distributed amplifier (CSSDA) technique. In this design, the conventional lowpass LC filter structure of the CMOS CSSDA is replaced by a bandpass LC filter structure lines. The CSSDA has a nearly constant gain, linear phase response, and accepta...

We propose a novel module as the main building block of a wireless surveillance system for homeland security applications. The proposed module houses processors (DC, IF and Microwave), cameras and batteries rechargeable by solar energy. Conformal solar panel and antenna are mounted on at least two of its surfaces. At least one inclined surface for...

A novel circular feed network is designed and utilized to feed an array of six equilateral triangular patches. The circular array can radiate in eight different directions depending on which of the four input ports are excited. The proposed feed network is considerably smaller compared to other networks with similar functions. Additionally it can s...

A novel method of designing a stepped impedance lowpass filter which involves the use of suspended substrate microstrip technology, to improve filter performance as well as multilayering for reduction in size, is reported. This filter has the sharpest cutoff when compared with microstrip and conventional suspended substrate microstrip filters. The...

A three-section loop directional filter on duroid-alumina substrates is successfully designed for a 3.5% bandwidth at 6 GHz with less than 4 dB insertion loss. It is seen that compact filters with steep roll-off and low insertion loss can be obtained with the multilayer approach.

An improved 3 dB broadband double-sided slot-coupled directional coupler has been designed and implemented. The slot is modified by trimming the sharp rectangular edges and the coupled microstrip lines in the coupling region. The performance of the coupler shows good agreement with the simulated frequency response. The main improvement is in the si...

The design methodology of a lowpass filter using transverse slit and parallel-coupled gap coplanar stripline (CPS) discontinuities is presented. A 5th order Chebyshev lowpass filter with a passband ripple of 0.5 dB is designed with a cut-off frequency of 5 GHz. Very good agreement has been observed between the experimental results and simulated dat...

In this work, a C-band passive microstrip four-element antenna-array beam-forming network (BFN) using high-directivity directional couplers is described. In the transmit mode, an input signal is split into four equiphase equiamplitude parts so as to correctly feed the elements of a linear/2-D array. The amplitude difference among the four feeds is...

The nonlinear response of a high-temperature superconductor hairpin-comb filter in a perpendicular dc magnetic field was examined through measurement of its insertion loss and center frequency. The effect of the applied field on the insertion loss at low field regime is small, and increases gradually with respect to the field. A hysteretic effect a...

This paper presents a set of newly developed computer-aided-design-oriented formulas for the evaluation of the quasi-static even- and odd-mode characteristics of conductor-backed coplanar-waveguide (CBCPW) coupled lines. This set of expressions is evaluated using a conformal mapping method based on the assumption of pure transverse-electromagnetic...

A Ku-band double-sided suspended substrate microstrip (DSSSM) coupled-line bandpass filter with less than 2 dB insertion loss is presented. The design utilises five sections and is specified to be centred at 15 GHz with a moderate 10% bandwidth which is fabricated on an alumina substrate (/spl epsi//sub r/ 9.9, h=0.381 mm and airgap=0.381 mm). The...

SUMMARY The conductor-backed asymmetrical coplanar waveguide or micro-coplanar strip (MCS)line has been analyzed. The conformal mapping method is used to calculate the quasi- static effective permittivity εef f and characteristic impedance Z0. The computed results of the present work are found to be in good agreement when compared with the results...

Several bowtie patch-antenna configurations are studied for their suitability for use in broad-band indoor wireless communications. A microstrip bowtie antenna (MBA), based on the design of equilateral triangular patches, is first designed and tested. The same design is used to realize a coplanar-waveguide bowtie antenna (CPWBA) with finite ground...

A compact monopulse comparator has been designed to operate from 8 GHz to 12 GHz. This new design is based on the direct connection of two Lange couplers, which eliminates the need for any transmission line for connection between the Lange couplers. This reduces any reflections due to mismatches and dispersion of the transmission lines and makes th...

In this work, a C-band passive microstrip 4-element antenna array beam forming network (BFN) using high-directivity directional couplers is employed (in the transmit mode) to split a signal into four equiphase equiamplitude parts so as to correctly feed the elements of a linear/2-D array. Amplitude difference between the four feeds is within 0.5 dB...

Wide-band frequency domain measurement and modeling of indoor radio channels at 5 GHz, for future HIPERLAN system are presented. Vector network analyzer is used to measure the frequency response of the channel. Impulse response profiles are obtained by using inverse Fourier transform. Empirical values of the RMS delay spread and number of multipath...

Several bowtie patch-antenna configurations are studied for their suitability for use in broad-band indoor wireless communications. A microstrip bowtie antenna (MBA), based on the design of equilateral triangular patches, is first designed and tested. The same design is used to realize a coplanarwaveguide bowtie antenna (CPWBA) with finite ground p...

A novel methodology is presented for the design of a wideband microstrip bowtie patch antenna (MBA) of finite length placed on a dielectric substrate. Here, a microstrip line feed network was used in HP Microwave Design System (MDS^TM) to match the MBA, since this type of feed network facilitates the construction of an array. Experimental...

The conventional end-coupled filter design approach, which requires a very small capacitive gap length, is modified by using edge-coupled sections to replace narrow gaps in order to reduce the sensitivity of the filter. A 5% bandwidth edge-end-coupled bandpass filter is designed at 4.9 GHz. The filter prototype is simulated using an electromagnetic...

A novel methodology is presented for the design of a wideband microstrip bowtie patch antenna of finite length placed on a dielectric substrate. The method presented is fast, computationally undemanding and reasonably accurate. This methodology is motivated by the observed array effect of the two trapezoidal halves on a single bowtie antenna. A sin...

Several DC blocks are built and tested to determine open-end length extension in coupled line circuits. For practical DC blocks, the line length extensions are found to vary between 5 and 20% of the design length. The results for length extension vs the gap length ranging from 0.1 mm to 0.7 mm for CPW DC blocks with finite ground planes are given i...

The ground plane of coplanar waveguide (CPW) does affect analysis if the dimensions are comparable to the elements. A simple relationship between the peak S11 response and ground width was found using a curve fitting process. A conservative limit in setting the ground width for “infinite” ground analysis was also verified. CPW lines in cascade was...

The design of a CPW loop bandpass filter is presented in this paper. The measured results have a high dependence on the bond wires used to connect the ground plane patches. Passband insertion loss is observed to increase significantly with no bond wires. Near maximally flat response is measured with a minimum number of bond wires, but with less att...

Inductively and capacitively end-coupled quarter-wavelength-resonator bandpass CPW filters are introduced. For a given bandwidth and passband shape, the new filters have a smaller size, wider upper stop band and looser coupling between resonators than end-coupled half-wavelength-resonator CPW filters. The design of two filters with 5% and 50% bandw...

The design and measured results for a microstrip loop directional filter formed by cascading two identical 4-resonator loop filters are presented. The second filter acts as a corrector whose output is added to the output of the first filter thereby minimising passband distortions and resulting in greatly improved performance

Finite ground plane coplanar waveguide edge-coupled bandpass filters which have no parasitic passband and low insertion loss are demonstrated. Two 5-section filters centred at 10 GHz with a 15% bandwidth with identical design parameters but different ground plane widths; are fabricated on alumina substrate; the measured passband insertion loss is <...

Coplanar-Waveguide (CPW) structures are becoming popular in microwave-integrated-circuit (MIC) and monolithic-MIC (MMIC) applications due to their uniplanar physical characteristics. For instance, the CPWs coplanar conductor and ground planes facilitate the grounding of shunt components. One circuit that takes advantage of this CPW property is the...

A novel microwave active bandpass filter has been designed in a coplanar waveguide. The approach uses a GaAs FET to link two end-coupled resonators. The realised active filter not only compensates for the losses as compared to a passive filter but also provides an overall gain of 17.54 dB. Flexibility in tuning the filter response through the bias...

The design of a bandpass type microstrip filter using phase velocity compensated wiggly edge-coupled sections is presented. Narrow bandwidth is achieved by employing identical coupled sections for the centremost and outermost sections of the filter thereby eliminating the need for extremely loose coupler.

A new design approach for thin-film codirectional quadrature couplers and their applications is described. An in-depth analysis and semi-empirical design curves are presented for these couplers. Forward-wave coupling is achieved by making use of the difference between even- and odd-mode phase velocities. Modified nonuniform codirectional couplers w...

Dummy channels are introduced into the coupled region to achieve physical realizability and significantly increase rejection in nonuniform type coupled-line filters. Theory is verified by a filter circuit designed on alumina substrate to demonstrate 4 different band-pass filters using two cascaded coupler-filters with 50% bandwidth at X-band. Rejec...

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A new design approach for microstrip sum-difference (Σ-Δ) Magic-T circuits is described. The technique employs entirely planar 0-dB and -3-dB codirectional quadrature couplers. A 17% bandwidth was demonstrated at the X -band from a Magic-T circuit built on a 1-in² alumina substrate. Multioctave 0-dB coupling is also illustrated by a comp...

Two possible ways of realizing wideband beamforming networks (BFNs) are presented. Initial physical values for backward-wave couplers can be maintained at fixed values irrespective of the coupling level. This significantly reduces alignment errors in the mask layout of a relatively large array. With codirectional couplers only a single 0 dB design...

Integrated 180° coupler circuits are described for use in monopulse direction finding systems. Σ-Δ Magic-T performance is obtained by using an almost 0 dB coupler and a -3 dB coupler

Wideband, entirely planar microstrip forward wave couplers are described. The technique uses a wiggly coupler structure in which the difference between odd- and even-mode phase velocities is controlled at any desired value by the amount of wiggle depth introduced between the conductors. In this way, forward coupling levels up to almost 0 dB can be...

Entirely planar microstrip bandpass filters are described for MIC (microwave integrated circuit) antenna applications. The technique uses almost 0-dB bandpass-type couplers. These filters have matched characteristics in the entire frequency range (i.e., both attenuation and passband). Passband flatness and sharpness are directly controlled by the f...

The design of a particular class of microstrip couplers and filters is presented. The synthesis functions obtained from the solution of first-order nonlinear differential equation of nonuniform lines with a loose coupling assumption are modified and validated for higher coupling values. The design employs a nonuniform coupled line configuration alo...

A new technique is presented for the realisation of 0 dB couplers in microstrip. This new technique involves the minimization of out-of-band coupling in nonuniform directional couplers by modifying the reflection coefficient distribution function. The selection of 0 dB coupling simplifies the theoretical formulation of coupling response of the nonu...

A novel class of microstrip bandpass/bandstop and periodic couplers and filters is described. Multifunction performance can be obtained from these components due to their directional properties. The design aspects and the predicted results of these circuits are presented. The theory is verified by an experimental bandpass coupler designed on an alu...

An experimental investigation of broadband microstrip antennas on a PTFE substrate with permittivity ε_r=2.1 and thickness h =1.6 mm is presented. A 17% bandwidth improvement is achieved by modifying the feed on the substrate with coaxial-fed disk antennas. Experiments carried out on circularly shaped modified patches showed a further ban...

The design of novel microstrip low-pass/high-pass couplers/filters is presented. The design is based on the equivalence principle of nonuniform transmission line directional couplers and the design procedure basically involves the determination of a realizable coupling coefficient function in the design bandwidth. The coupling coefficient distribut...

A periodic branching microstrip filter using -3 dB directional couplers and short lengths of microstriplines with improved frequency characteristics is described in this paper. The designed filter separates the 2-18 GHz input signal into four 4 GHz contiguous channels. The design of the periodic branching filter and experimental results are present...

A computer-aided synthesis design procedure is given for nonuniform quadrature directional couplers in inhomogeneous media. A wiggly geometry is used which effectively slows the odd-mode phase velocity to match the even-mode phase velocity. The wiggly geometry results in improved isolation and increased effective dielectric constant. This technique...

The design principles of microstrip channelling filters using -3 dB directional couplers are given. The measured results of an experimental multiplexer built on alumina substrate are also presented

A 2-20 GHz, -3 dB 90-degree directional coupler is designed and built on an alumina substrate. The overall area occupied by the coupled is reduced by selecting a nonzero value for the initial coupling coefficient. A considerable improvement in the coupler performance is also achieved due to the reduced slopes of the wiggly coupled lines. Coupler de...

A computer-aided-design (CAD) synthesis procedure using cubic splines for wideband symmetrical nonuniform directional couplers in inhomogeneous media is presented. Solutions for the potential problems inherent to these couplers are given. Results are presented for a 2-18-GHz, five-section, -3-dB nonuniform tandem directional coupler designed and bu...