WSEAS CONFERENCES. WSEAS, Unifying the Science

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Volume 9, 2010
ISSN: 1109-2734
E-ISSN: 2224-266X








Issue 1, Volume 9, January 2010

Title of the Paper:  Quantum-Well Tridiagonal: A Qualitative Comprehension of Optoelectronics Nanotechnology


Authors: E. A. Anagnostakis

Abstract: A simple effective algorithm (“QUANTUM-WELL TRIDIAGONAL”) for studying the essential features, causalities, and applicabilities of an optoelectronics nanoheterointerfacial generic quantum well (QW) is outlined in terms of transforming the pertinent initial Schroedinger equation into a normalised Sturm – Liouville one and, ultimately, into an eigensystem concerning a specific tridiagonal matrix. A qualitative comprehension of optoelectronics nanotechnology basics is, thus, envisaged to be offered.

Keywords: Quantum-well tridiagonal, optoelectronics, nanoheterointerfacial, quantum well, schroedinger equation, sturm – liouville equation, nanotechnology

Title of the Paper:  Performances of CMOS Thermal-Compensation Total-Current References


Authors: Radu D. Mihaescu, Mircea A. Ciugudean

Abstract: "Total"-current reference sources, composed of two classic cross-connected current mirrors, have been launched by the authors in some earlier published works. Theirs major advantages are: simple serially interconnection with the charge and the minimum supply current (this is just the reference current). This work is a comparative analysis of the performances of two total-current reference-source variants with first and second-order thermal compensation, using different integrated resistor types, having positive, zero or negative temperature coefficient. The possibility of obtaining a set of good performances by using NTC resistors is signalled but also, the inefficiency of second-order thermal-compensation for many cases of resistor- temperature-coefficient combinations. A total temperature variation of the reference current, for a particular source variant, is reported, which represents a record: 0.017% for a temperature range of 0-100oC.

Keywords: Analogue Integrated Circuits, CMOS Current Reference, Thermal Compensation, Total-Current Reference

Title of the Paper:  Simulation the Functionality of a Laser Pulse Image Acquisition System


Authors: Toadere Florin, Nikos E. Mastorakis

Abstract: The goal of this paper is to generate a laser pulse and to capture it by an image acquisition system. We use a confocal resonator to generate a laser pulse; then the generate light is focused in to an optical fiber using a lens; the light propagates through the fiber and at the fiber output light is projected on a CMOS sensor. We compute the PSF (point spread function) and MTF (modulation transfer function) in order to characterize the functionality of the lens and the optical part of a CMOS sensor. We analyze the CMOS electrical part considering the photon shot noise and the FPN (fixed pattern noise). Finally, we use a Lapacian filter, an amplitude filter and a bilateral filter in order to reconstruct the noisy blurred image. We consider the image capture system to be linear shift invariant, axial and the light is orthogonal to the system.

Keywords: Hermite Gaussian polynomial, lens design, PSF, MTF, fixed pattern noise, photon shot noise, amplitude filter, Laplacian filter, bilateral filter

Title of the Paper:  An Overview about Monitors Colors Rendering


Authors: Toadere Florin, Nikos E. Mastorakis

Abstract: The goal of this paper is to study how different TV technologies work, and to compare them. We analyze three different situations: a CRT monitor, a LCD monitor and a LEDs monitor. Using the different monitors’ spectral power distributions, we propose a six steps spectral image processing algorithm which converts the spectral image in to XYZ standard and then in to the RGB standard. Finally we colour balance the RGB image in order to eliminate the monitors unwanted render colours hues. On the monitors displays we expect to see the same colours text image. Also we present the monitor’s colours properties like: colours saturation, brightness, contrast and sharp.

Keywords: Spectral image, CRT, LCD, LED monitors, monitors spectral power distribution, render image colors properties

Title of the Paper:  A Novel Design for Evaluating Simultaneous Switching Noise within an Enhanced IBIS Model


Authors: Wen-Tzeng Huang, Sun-Yen Tan, Yuan-Jen Chang, Chiu-Ching Tuan

Abstract: Simultaneous switching noise (SSN) is a major cause of power integrity (PI) degradation that causes circuits to become unstable and experience errors. As modern ICs operate at higher speeds with higher density and lower voltages, SSN has become a serious issue that must be addressed to ensure system stability during the short rise- and fall-times of the logic transient states. Most traditional designs have generally used decoupling capacitors to reduce SSN. As these capacitors become equivalent series inductances when the system operates at high frequencies, such a technique works against reducing SSN. Therefore, we propose a methodology called the enhanced IBIS model that effectively alleviates the problem of SSN using an evaluation based on the enhanced I/O buffer information specification (IBIS) model with decoupling capacitors and a high-frequency low-impendence circuit. In this study, we showed that SSN from 452 mV, 290 mV, 163 mV, and 301 mV, of IBIS, traditional decoupling capacitors, IBIS with a high-frequency low-impendence circuit, and HP Simulation Program with Integrated Circuit Emphasis (HSPICE) methodologies, respectively, was effectively reduced by 121 mV of our enhanced IBIS mode as measured by the peak-to-peak value. That is, our new method reduces noise by more than 73.2%, 58.3%, 25.7%, and 59.8% compared to other four methodologies, respectively.

Keywords: Simultaneous Switching Noise (SSN), Power Integrity (PI), I/O Buffer Information Specification (IBIS), HSPICE, High-frequency low-impedance (HFLI) circuit

Title of the Paper:  Design and Implementation of a Negative Feedback Oscillator Circuit Based on a Cellular Neural Network with an Opposite Sign Template


Authors: Baran Tander, Atilla Ozmen, Yasin Ozcelep

Abstract: In this paper, explicit amplitude and frequency expressions for a Cellular Neural Network with an Opposite-Sign Template (CNN-OST) under oscillation condition are derived and a novel inductorless oscillator circuit with negative feedbacks, based on this simple structure is designed and implemented. The system is capable of generating quasi-sine signals with tuneable amplitude and frequency which can’t be provided at the same time in the classical oscillator circuits.

Keywords: Oscillator Circuits, Cellular Neural Networks, Quasi-Sine Signals, Curve and Surface Fitting, Operational Amplifiers, Circuit Design

Issue 2, Volume 9, February 2010

Title of the Paper:  Automated Traffic Light System for Road User's Safety in Two Lane Road Construction Sites


Authors: Siva Kumar Subramaniam, Vigneswara Rao Ganapathy, Sivarao Subramonian, Abdul Hamid Hamidon

Abstract: The road construction safety traffic light system is designed to replace a manual traffic control on a road construction sites. This device can replace one or both flaggers during the two lane closures on the event of a road construction. The road construction safety traffic light system is considered one of the best devices in work zone traffic flow control systems. The device is a portable traffic light unit which can be best utilized in controlling traffic flow in a road construction site for long term or short term lane closures and to control two-way traffic in a single lane. By implementating new technologies in automating traffic flow in road construction site could possibly eliminate the usage of a conventional flagman at all times. The road construction safety traffic light system is a practical solution to solve problems which contribute towards hazards at road construction site and to be inline with the road safety regulation which is taken into granted by the contractors. The automated portable traffic light system can reduce direct costs in man power utilization and increase safety for the road users and construction workers by eliminating the need for a human flagmen. This system is applicable for public and privately funded road construction projects that require overnight or 24-hour traffic control as well as in different weather conditions.

Keywords: Intelligent traffic light system, programmable logic controller, smart control application, flagman, traffic light

Title of the Paper:  State-Space Averaging (SSA) Revisited: On the Accuracy of SSA-Based Line-To-Output Frequency Responses of Switched DC-DC Converters


Authors: Viera Biolkova, Zdenek Kolka, Dalibor Biolek

Abstract: The line-to-output (LTO) frequency response of switched DC-DC converter describes how the smallsignal harmonic perturbation of the converted input DC voltage penetrates into the converter output, depending on the frequency of this perturbation. In the paper, the LTO frequency response conceived in this sense is faced with the LTO response, obtained by applying the well-known State-Space-Averaging (SSA) technique to switched converters, with the aim of determining the fundamental limitations of the SSA-approach. The general analysis is then applied to Buck-, Boost-, Buck-Boost-, and Cuk- type converters. It is shown that the accuracy of SSA outputs is related to the character of the state matrices of the converters.

Keywords: Switched DC-DC converter, averaging, SSA, spectrum, LTO frequency response

Title of the Paper:  Comparative Study of Noise Reduction in Ultrasonic Inspection System


Authors: Jaejoon Kim

Abstract: The effective noise reduction schemes in ultrasonic inspection have shown significant role for detection of flaws in materials. This paper presents the comparative result of noise reducing schemes based on Hilbert-Huang transform and Wavelet transform. The basic principle of HHT scheme includes two parts which are empirical mode decomposition (EMD) algorithm and a sum of intrinsic mode functions (IMF). By doing EMD process, the valuable information out of individual IMF can be maintained with reduced noise level for feature vectors. In the Wavelet transform, the signals are decomposed into low and high information and the feature vectors can be selected by Wavelet coefficients. In order to compare the performance of the two distinct schemes, this paper utilizes the soft and hard thresholding criterion on WT and HHT.

Keywords: Ultrasonic inspection, Automatic signal processing, Hilbert-Huang Transform, Wavelet Transform, Denoising scheme, Nondestructive evaluation

Title of the Paper:  Evaluating Multicast Resilience in Carrier Ethernet


Authors: Sarah Ruepp, Henrik Wessing, Jiang Zhang, Anna V. Manolova, Anders Rasmussen, Lars Dittmann, Michael Berger

Abstract: This paper gives an overview of the Carrier Ethernet technology with specific focus on resilience. In particular, we show how multicast traffic, which is essential for IPTV can be protected. We detail the background for resilience mechanisms and their control and we present Carrier Ethernet resilience methods for linear and ring networks. By simulation we show that the availability of a multicast connection can be significantly increased by applying protection methods.

Keywords: Carrier Ethernet, Resilience, IPTV, Simulation, Protection, OAM

Title of the Paper:  Evaluation of Dynamic Bandwidth Allocation Algorithms in GPON Networks


Authors: Joanna Ozimkiewicz, Sarah Ruepp, Lars Dittmann, Henrik Wessing, Sylvia Smolorz

Abstract: In this paper, two approaches for Dynamic Bandwidth Allocation in GPON networks are proposed, and validated through simulations in the OPNET modeler. One approach address a Status Reporting scheme, where the bandwidth allocation originates from the client request. The second use a centralized Non Status Reporting scheme. Furthermore, parameters to cope with variances in the traffic pattern is quantified. The results on performance, scalability and efficiency show that Status Reporting is utilizing the bandwidth more efficient while the Non Status Reporting provides better QoS for real time services.

Keywords: GPON, dynamic bandwidth allocation (DBA), simulation, status reporting, OPNET

Title of the Paper:  Testing of High Breaking Capacity Fuses Using Modular Current Sources


Authors: Adrian Plesca, Emilian Furnica

Abstract: There are many types of switching and protection electrical apparatus used in different power systems with the goal to supply at adequate parameters industrial or domestic consumers. The time-current characteristics of the protection electrical apparatus from datasheets have accuracy up to ± 30%. Hence, in order to achieve a safe protection at overcurrents it is necessary to test the electrical apparatus using proper devices. Therefore, the aim of this paper is to present new types of modular current sources and some possibilities to adjust their parameters. Then, a method to obtain the time-current characteristics of low voltage high breaking capacity fuses without fusing is presented.

Keywords: Modular current source, testing, method, high breaking capacity fuse

Issue 3, Volume 9, March 2010

Title of the Paper:  Nanometric Layers of Cadmium Sulphide by CBD and a Potential Application


Authors: M. C. Acosta-Enriquez, A. Apolinar-Iribe, M. E. Alvarez-Ramos, M. A. Quevedo-Lopez, R. Ramirez-Bon, A. F. Jalbout, A. De Leon, A. Duartemoller, R. P. Duarte-Zamorano, L. E. Regalado, M. R. Manzo-Valencia, S. J. Castillo

Abstract: We presented an application of nanometric layers of Cadmium Sulphide developed using Chemical Bath Deposition (CBD) technique for the growth of the CdS thin films. The thin films of CdS were synthesized employing two different complexing agent, acetilacetone and glycine. In this paper we compare the results of the thin films characterization with both complexing agent and the CdS thin film growth with glycine was selected in order to develop a Thin Film Transistor (TFT). The energy bandgaps in these cases were Eg = 2.53 eV using glycine as complexig agent, and Eg= 2.37eV using acetylacetone as complexing agent. An hexagonal polycrystalline structure concerning to the X-ray analysis results for both processes, from those studies were calculated their grain sizes by the model of Debye-Scherrer, resulting 3 nm for the acetylacetone process and 30 nm for the glycine process. Also we started with the computational analysis and preliminary results are presented.

Keywords: Cadmium Sulfide, Semiconductors, Thin Films, Acetylacetone, Glycine and Transistors

Title of the Paper:  Formation of ZnO in or on Glasses by Using the Sol-Gel and Chemical Bath Deposition Techniques


Authors: S. J. Castillo, M. C. Acosta-Enriquez, Ma. E. Zayas, H. Arizpe, T. Mendivil-Reynoso, A. Garcia-Juarez, M. E. Alvarez-Ramos, E. Larios-Rodriguez

Abstract: In the first part of this work was produced Zinc Oxide (ZnO) into a glass matrix by using the Sol-Gel Technique at room temperature, these materials were prepared using tetraethyl orthosilicate (TEOS) as precursor, the Zn ions were added before the jellification step trough an aqueous solution of zinc acetate. These glasses were characterized by X-ray diffraction, optic absorption, FT-IR and Raman spectroscopy. The X-ray patterns showed amorphousness. The optical absorption shows a shoulder in the UV range corresponding whit ZnO confined to the vitreous matrix. The spectra by FT-IR show characteristic vibrations of Si-O-Si with interaction Zn+2. Raman scattering let us to identify and precise the formation of the ZnO. In the second part of this work was immersed glass substrates into an aqueous chemical bath with external controlled temperature, the chemical solutions contained in the bath were a Zn Ions source (ZnSO4) 0.1 M, a pH 10 Buffer solution (NH4Cl/NH4OH), Ethanolamine to complex the Zn ions, and pure water, resulting ZnO films hexagonally structured with energy band gap of 3.3 eV, growing 1000 nm during 25 minutes followed of 60 minutes to 75°C and 85°C in the same chemical reaction.

Keywords: Glasses, Zn Ions, Zinc Oxide, Sol-Gel Process, Thin Films, Chemical Bath Deposition and semiconductors

Title of the Paper:  Efficient Interconnect Design with Novel Repeater Insertion for Low Power Applications


Authors: Tripti Sharma, K. G. Sharma, B. P. Singh, Neha Arora

Abstract: Length of interconnect and number of repeaters are increasing with the advancement in VLSI Technology. Requirement of repeaters is increasing as the length of interconnect is increasing. The power delay product and frequency of operation plays significant role in designing of repeater. Performance of earlier conventional repeater with the proposed sub-threshold grounded body (STGB) bias repeater for various lengths of interconnects is analyzed. The simulation results shown in the paper indicates that the STGB bias repeater circuit operates in medium frequency range with better power-delay product as compared with the previous repeater. The temperature sustainability and performance with the variation of aspect ratio is also better for STGB bias repeater. Reduction of overall delay, power dissipation as well as operation of the repeater at higher frequencies can lead to the better performance of the VLSI chip in sub-threshold region.

Keywords: VLSI, Interconnect, Sub-threshold, Repeater, Buffer, novel approach, conventional buffer, portable applications

Title of the Paper:  Investigation of the Heat Meters Calculator Applying a Measurement Devices Software Reliability Method


Authors: V. Knyva, M. Knyva

Abstract: Nowadays, parameters, characteristics and functionality of measurement devices basically depend on microprocessors software. Software used in measurement devices overtakes functions from a hardware part of the device. For example, data processing algorithms, control functions are implemented using software. Basically during verification of the device, just a hardware part of the device is verified. But software controls all the functions of the measurement device. Therefore, a method for metrological estimation of reliability of measurement devices software will be presented.

Keywords: Software validation, metrology, measurement devices, verification and testing of software

Title of the Paper:  Adiabatic and Standard CMOS Interfaces at 90 nm Technology


Authors: Neha Arora, B. P.Singh, Tripti Sharma, K. G. Sharma

Abstract: Adiabatic circuits and standard CMOS logic are widely employed in Low power VLSI chips to achieve high system performance. The power saving of adiabatic circuit can reach more than 90% compared to conventional static CMOS logic. The clocking schemes and signal waveforms of adiabatic are different from those of standard CMOS circuits. This paper investigates the design approaches of low power interface circuits in terms of energy dissipation. Several low power interface circuits that convert signals between adiabatic logic and standard CMOS circuits are presented. With BSIM3v3 90nm CMOS technology, the energy consumption of proposed interface circuits has relatively large power saving over the wide range of frequencies. This paper also investigates the different power delay product over the wide range of supply voltages. Power dissipation has been calculated for different values of temperature. The proposed circuits are showing the best results on various ranges of temperature. Simulation has been done on tanner EDA tool at BSIM3v3 90nm technology.

Keywords: Standard CMOS logic, adiabatic circuit, Interfaces, Low power, Power delay Product, Energy dissipation, Power Dissipation

Title of the Paper:  Application of Genetic Algorithms for Optimal Reactive Power Planning of Doubly Fed Induction Generators


Authors: P. Sangsarawut, A. Oonsivilai, T. Kulworawanichpong

Abstract: This paper describes optimal reactive power control of a doubly fed induction generator (DFIG), which is widely used in a distributed generating plant. Although its structure is similar to that of induction motors, its reactive power control is more complicated. In this paper, steady-state power transfer equations are derived and developed for a doubly fed structure of the induction generators. When a distributed power plant equipped with DFIGs is connected to a regional power grid, reactive power injection from the plant results in distribution system performances, e.g. voltage drop, power losses, etc. By using genetic algorithms, optimal reactive power injection can be achieved in order to minimize total power loss in power distribution systems. The 37-node IEEE standard test feeder is used to evaluate its performances. As a result, optimal reactive power control of DFIGs can reduce total power losses and also improve voltage profiles in power distribution systems.

Keywords: Optimal reactive power planning, doubly fed induction generator, optimization, genetic algorithms

Issue 4, Volume 9, April 2010

Title of the Paper:  Development and Calibration of an Impulse Magnetic Field Measurement System for Lightning Electromagnetic Pulse Investigation


Authors: Xiao-Ming Ren, Zheng-Cai Fu, Wei Sun

Abstract: In order to evaluate the impulse magnetic field distribution inside buildings truck by lightning or by nearby stokes, a set of measuring system composed of self-made magnetic detection coil and fiber transmission system was developed. The sensitivity coefficient of the optical fiber transmission system was calibrated by sine wave generator. Connecting the output of a portable 8/20μs current generator with a circular coil whose diameter is 0.3 m to compose the magnetic field generator, the detection coil was fixed in the center of the circular coil for calibration. The B/V calibrated coefficient error of the system is less than 3%. A demonstrating application of the developed measurement system is in the investigation of the electromagnetic environment in buildings under direct and nearby lightning strokes. Experimental verification of such application has been carried out on metal frame structure models of building in laboratory. Two scaled metal frame structure models are set up in the laboratory. The measured transient magnetic field distributions inside the building frame structures are verified by comparison of the testing results with the calculated results using the circuit method simulation. In the circuit method, the lightning channel and the building’s metal cage are modeled by a multi-conductor system. Every branch conductor is divided into several suitable segments. The length of each segment is less than one tenth of the wavelength corresponding to the maximum frequency in the equivalent spectrum of the lightning transient current. Each segment is modeled by a coupled -type lumped circuit. The test results of the developed measurement system coincide with the calculated results well. Under the situation of nearby lightning strokes, the developed measurement system is also used for the investigation of the shielding effectiveness of the building frame structure. The test results of the shielding effectiveness on the metal frame structure model shows that the effectiveness coefficient increases with the decrease of grid width of the frame. While the width of the grid changes from 0.5m to 0.25m, there is an increase of shielding effectiveness of approximately 10.2%. While the width of grid changes from 0.25 m to 0.125 m, the shielding effectiveness increases about 5%. To simulate the situation when metal plate wall exists in the building, 0.5 mm steel plate was attached on the frame structure model. Under such situation, the shielding effectiveness increases to 4.9. The application experiments of the developed measurement system show that it can fulfill the requirements of lightning impulse magnetic field measurement.

Keywords: Impulse magnetic field, calibration, magnetic field generator, magnetic field measurement, lightning protection, fiber transmission system

Title of the Paper:  Analysis and Control of Two Switches AC Chopper Voltage Regulator


Authors: Jin Nan, Tang Hou-Jun, Bai Liang-Yu, Geng Xin, Yang Xiao-Liang

Abstract: In this paper, an improved topology of Buck type AC chopper voltage regulator and its control strategy are proposed. This converter only using two power switches is low cost, easy implemented and the phase synchronized circuit is not needed. The current path is provided in dead-time period by using simple snubber circuit. The over-voltage protection varistor is also applied to absorb the voltage spikes which may destroy the power switches. The voltage spikes in dead-time mode commutation are greatly reduced and the power switches are protected. Furthermore, the feedforward and feedback control strategy is proposed to suppress fluctuations and eliminate the harmonic components caused by power quality problems of the input voltage. The proposed converter could realize wide range voltage regulation with high power transfer efficiency and low total harmonic distortion. The steady-state equivalent circuit and the input power factor are derived through theoretical analysis. The output filter design method is also presented. Based on the theoretical analysis and calculation, an experimental prototype is setup. The simulation and experiment results verify the validity of the proposed design.

Keywords: AC chopper, Voltage Regulator, Pulse Width Modulation, Feedforward and Feedback Control, Power Factor, Voltage Fluctuations

Title of the Paper:  Fault Tolerance Design by Accurate SER Estimation for Nano-Scale Circuits


Authors: Yu Changhong

Abstract: As the transistor sizes continue to shrink, quantum effects will significantly affect the circuit behavior. The inherent unreliability of nano-electronics will have significantly impact on the way of circuits design, so defects and faults of nano-scale circuit technologies have to be taken into account early in the design of digital systems. Fault-tolerant architectures may become a necessity to ensure that the underlying circuit could function properly. In CAD software, a same logic can be made out with different circuits but different design methodology can reach different soft error tolerance ability, so we must find a way to estimate the error rate of the circuit efficiently to make the design more fault tolerant. In this paper, a new way to fault tolerance design in nano-scale circuit by accurate soft error rate (SER) estimation is proposed. Transform matrix is used for SER computation and a design criteria is then proposed. Simulation results show that the proposed transform matrix model is effective for nano-scale circuits and the criteria delivered is suitable CAD tools development in nano-system design.

Keywords: Nano-system, SER estimation, Transform matrix, Matrix analysis, Condition number, Fault tolerant design

Title of the Paper:  Nonlinear Adaptive Controller Design of SSSC for Damping Inter-Area Oscillation


Authors: Lihong Gu, Xiaoxin Zhou, Min Liu, Haobo Shi

Abstract: This paper presents a novel nonlinear adaptive control scheme of static synchronous series compensator (SSSC) to enhance the transmission power and damping of inter-area oscillation mode for multi-machine power system.. The SSSC device was treated as a first order voltage resource and the multi-machine system was simplified into a two-machine model. Based on the exact feedback linearization theory, Lyapunov stability theory, and adaptive control law, the nonlinear adaptive controller of SSSC is derived. Unknown system parameters are considered for improving robustness. The simulation results validate the efficacy of the proposed controller.

Keywords: Power system, SSSC, inter-area oscillation, nonlinear adaptive control, Lyapnuov stability

Title of the Paper:  Infrared Thermal Detectors Parameters: Semiconductor Bolometers Versus Pyroelectrics


Authors: Genc Hyseni, Nebi Caka, Kujtim Hyseni

Abstract: Semiconductor bolometric detectors parameters have been analyzed within the wavelength of 100μm up to 3mm and cryogenic temperatures. From analyses and results obtained, it is shown that the values of NEP have been found to be 16.4?10-15W/Hz-1/2 and 38.466?10-15W/Hz-1/2 for cryogenic temperatures 0.5K and 5K, respectively. For the wavelength 200 μm, the maximum value of the voltage responsivity RV of the bolometer is 0.106?10-11 V/W, while for the wavelengths 1 mm, 2 mm and 3 mm, corresponding values of voltage responsivity RV of the bolometer are 0.53?10-11 V/W, 0.58?10-11 V/W and 0.637?10-11 V/W, respectively. This paper also outlines analyzes of the temperature dependency of infrared pyroelectric detectors parameters at medium wavelength (MWIR). Certain pyroelectric materials such as TGS, LiTaO3, LiNbO3, Li2SO4xH2O, BaTiO3, NaNO2, PVF2, SBN and SbSi have been analyzed within the temperature range of 273K up to 343K. Analytically it is proven that thermal time constant decreases with increasing temperature and decreasing the thickness of the detector. Analyses have shown that the smallest response time for detector which operates at room temperature 300K was achieved for the material Li2SO4?H2O with value of several milliseconds, but anyway much greater then that of photon detectors. It is also shown that NEP depends directly on circuit noises voltages. In the paper are analyzed three types of noises: thermal noise, dielectric noise, and amplifier noise. The maximum possible value of detectivity to be achieved for a MWIR infrared pyroelectric detector operates at room temperature 300K was 2.12?108 for NaNO2.

Keywords: Infrared, bolometers, pyroelectricity, pyroelectric detectors, responsivity, thermal time constant, NEP, detectivity

Title of the Paper:  Preservation of Synchronization in Dynamical Systems via Lyapunov Methods


Authors: G. Fernandez Anaya, C. Rodriguez Lucatero, J. J. Flores-Godoy, C. Miranda-Reyes

Abstract: In this paper, we use, extend and apply some classic results of the theory of dynamical systems to study the preservation of synchronization in chaotical dynamical systems via Lyapunov method. The obtained results show that synchronization can be preserved after a particular class of changes are made to the linear part of the dynamical system. For illustrative purposes we apply a compound control law to achieve synchronization in a master-slave system. We also show that it is possible to preserve partial synchronization when an additive perturbation is included in the control law. We present numerical simulations to show the effectiveness of our method.

Keywords: Chaotic Systems, control theory, convergence, stability

Title of the Paper:  An Implementation of Parallel Power Flow Calculation based on Graph Partitioning Algorithm


Authors: Wenkai Zhao, Xinyan Fang, Xu Dong, Yuan Bi, Ying Wu

Abstract: In coarse-grained parallelism, it is effective to partition the network into Bordered Block Diagonal Form (BBDF) before subsequent parallel computation. An implementation of parallel power flow calculation based on a novel graph partitioning algorithm, which transforms the admittance matrix into nested BBDF (NBBDF),is presented in this paper. In order to avoid excessive fill-ins during Gaussian elimination, a vertex ordering scheme is discussed. Distributed file storage combined with task scheduling is proposed for improving parallel efficiency. Testing results for grids with up to 5317 buses indicate that this proposed method is able to bring superlinearity into parallel power flow calculation for large-scale power systems.

Keywords: Parallel power flow calculation, power systems, graph partitioning algorithm

Title of the Paper:  A Ring Oscillator of Remarkable Power Supply Independent Characteristic


Authors: Mohammad Hassan Montaseri

Abstract: A highly power supply independent Ring Oscillator architecture is proposed in this paper. The proposed architecture is achieved using the advantages of best previous techniques. Making use of opposite characteristics of the delay cells along with power supply isolation and self-biasing have resulted in a nearly 1% sensitivity; a record better than all previous architectures. To accomplish such robustness, different delay stages with different characteristics have been used in the proposed architecture. Simulations based on 0.5μm CMOS technology confirm robustness of the proposal.

Keywords: Ring Oscillator, Voltage Controlled Ring Oscillator, Power Supply Variation, Frequency Stability

Issue 5, Volume 9, May 2010

Title of the Paper:  A Ring Oscillator with High Temperature Independency


Authors: Mohammad Hassan Montaseri

Abstract: A novel temperature independent Ring Oscillator is proposed in this paper. In order to accomplish temperature independency, different characteristics of several delay stages are gathered together in one circuit scheme. Using the temperature property of one kind of delay stage to cancel the other’s, has made the proposed architecture show drastically low temperature sensitivity. The proposed architecture was simulated in 0.35μm CMOS technology where the temperature varied from 0 to 50 degrees Celsius, resulting in only 1% frequency deviations.

Keywords: Ring Oscillator, Voltage Controlled Oscillators, Ring Oscillators, Temperature Variations, Frequency Stability

Title of the Paper:  Transport Supervision of Perishable Goods by Embedded Context Aware Objects


Authors: A. Wessels, R. Jedermann, W. Lang

Abstract: Intelligent freight objects can be introduced in order to simplify the solution of complex logistical planning tasks. This enables splitting logistical problems to local executable subtasks. The concept of Ubiquitous Computing (UbiComp) presents a model to realize such intelligent objects. A local task can be handled autonomously by a group of objects. The realization of UbiComp needs a platform that first provides the computational resources for the implementation of decision algorithms and then, secondly, the position information in order to enable context-aware features. This article presents a concept for the autonomous supervision of perishable goods and introduces the required soft- and hardware. Freight objects are represented by individual software components, which are realized with the JAVA framework OSGi. The whole software is designed to run on wireless sensor nodes to create embedded objects. Because temperature values can differ inside a reefer container, the signal strength of an RFID reader is used to provide position information by a cell based localization. A new approach is presented, where four RFID antennas are used to locate goods inside a container.

Keywords: Ubiquitous Computing, embedded Systems, JAVA, OSGi, localization, RFID, RSSI

Title of the Paper:  Design of a Simple OTA-Based Mixed-Signal Controller for Adaptive Control System of Shunt Active Power Filter


Authors: Sombat Vanichprapa, Cherdchai Prapanavarat, Boonruk Chipipop

Abstract: This paper presents a simple mixed-signal controller using OTA (Operational Transconductance Amplifier) – based circuit for the adaptive control system of shunt active power filter (APF). The DC bus voltage detection method is proposed for the control scheme. The simple OTA multiplier circuit, OTA-C Canonical second-order filter circuit and OTA-C plus OTA summator circuit is designed for the reference-sine-wave signal generator including Low Pass Filter and PI controller. The LM13700 is represented for the OTA simulated model which is developed for using with the 50 Hz three-phase three-wire system utility. The advantage of using OTAbased circuits is its adaptive control and real-time processing which is suitable for high frequency power switches of the active power filter without using A/D converter. The simulation results show that OTA-based circuit can be used as the adaptive controller of APF which is simpler design compared to DSP, moreover, it can be fabricated in one single chip by using CMOS technology.

Keywords: Active power filter, adaptive, circuits, controller, mixed-signal, OTA, simple

Title of the Paper:  A VHDL-Based Design Methodology for Asynchronous Circuits


Authors: Sun-Yen Tan, Wen-Tzeng Huang

Abstract: The asynchronous circuit style is based on micropipelines, a style used to develop asynchronous microprocessors at Manchester University. This paper has presented some engineering work on developing a micropipeline blocksorter. The work presented in this paper demonstrates that VHDL can be used to describe the behaviour of micropipelined systems. It also shows a comparison of 2-phase and 4-phase implementations in transistor count, speed, and energy. Though the nature of the work is mainly engineering, there are some significant new insights gained in the course of the work. In summary, a design environment for asynchronous circuits has been established based upon the micropipeline style and VHDL, a standard hardware description language.

Keywords: Asynchronous design, Micropipelines, Blocksorter, VHDL, Synthesis

Title of the Paper:  Piezoresistive Microcantilever Biosensor Potentiometric Signal Transduction for Human Stress Measurement


Authors: Nina Korlina Madzhi, Anuar Ahmad, Lee Yoot Khuan, Mohd Firdaus Abdullah

Abstract: This paper deals with the development of Piezoresistive Microcantilever biosensor and the signal transduction to detect human stress by using salivary alpha amylase activity. A Piezoresistive Microcantilever biosensor can be used to detect saliva-amylase activity by deflecting upon interaction with a specific receptor. By measuring the amount of bending the microcantilever beam experiences in response to interactions with the molecules, and the amount of analyte in the solution can be quantified. When the Microcantilever beam deflects it caused the stress change within the microcantilever beam and applied strain to the piezoresistor material thereby causing the resistance change which can be measured with the Wheatstone Bridge circuit. The Piezoresistive Microcantilever sensor integrated with transducer components converts the biochemical signal into measurable signal when it react with salivary amylase enzyme. The enzyme concentration signal is converted to a voltage signal by the transducer. The device was designed specifically that it enables the small resistivity change due to the enzymatic reaction to be measured.

Keywords: Biosensor, Piezoresistive, Microcantilever, Signal Transduction, Resistance change, Saliva, Alpha Amylase

Title of the Paper:  A Novel Linear Array for Discrete Cosine Transform


Authors: Yaw-Shih Shieh, Tze-Yun Sung, Hsi-Chin Hsin

Abstract: Discrete cosine transform (DCT) and inverse DCT (IDCT) have been widely used in many image processing systems. In this paper, a novel linear-array of DCT and IDCT is derived from the data flow of subband decompositions representing the factorized coefficient matrices in the matrix formulation of the recursive algorithm. For increasing the throughput as well as decreasing the hardware cost, the input and output data are reordered. The proposed 8-point DCT/IDCT processor with four multipliers, simple adders, and less registers and ROM storing the immediate results and coefficients, respectively, has been implemented on FPGA. The linear-array DCT/IDCT processor with the computation complexity O(5N / 8) and hardware complexity O(N / 2) is fully pipelined and scalable for variable length DCT/IDCT computations.

Keywords: DCT/IDCT, subband decomposition, linear-array, pipelined, scalable

Title of the Paper:  Reconfigurable Architecture for VLSI 9/7-5/3 Wavelet Filter


Authors: Tze-Yun Sung, Hsi-Chin Hsin

Abstract: In this paper, the high-efficient and reconfigurable lined-based architectures for the 9/7-5/3 discrete wavelet transform (DWT) based on lifting scheme are proposed. The proposed parallel and pipelined architectures consist of a horizontal filter (HF) and a vertical filter (VF). The critical paths of the proposed architectures are reduced. Filter coefficients of the biorthogonal 9/7-5/3 wavelet low-pass filter are quantized before implementation in the high-speed computation hardware In the proposed architectures, all multiplications are performed using less shifts and additions. The proposed reconfigurable architecture is 100% hardware utilization and ultra low-power. The proposed reconfigurable architectures have regular structure, simple control flow, high throughput and high scalability. Thus, they are very suitable for new-generation image compression systems, such as JPEG-2000.

Keywords: Reconfigurable architecture, 9/7-5/3 discrete wavelet transform (DWT), horizontal filter (HF), vertical filter (VF), lifting scheme

Title of the Paper:  Multiplierless, Reconfigurable Folded Architecture for VLSI Wavelet Filter


Authors: Tze-Yun Sung, Hsi-Chin Hsin, Sheng-Dong Chang

Abstract: In this paper, the high-efficient and reconfigurable architectures for the 9/7-5/3 discrete wavelet transform (DWT) based on convolution scheme are proposed. The proposed parallel and pipelined architectures consist of a high-pass filter (HF) and a low-pass filter (LF). The critical paths of the proposed architectures are reduced. Filter coefficients of the biorthogonal 9/7-5/3 wavelet low-pass filter are quantized before implementation in the high-speed computation hardware. In the proposed architectures, all multiplications are performed using less shifts and additions. The proposed reconfigurable architecture is 100% hardware utilization and ultra low-power. The proposed reconfigurable architectures have regular structure, simple control flow, high throughput and high scalability. Thus, they are very suitable for new-generation image compression systems, such as JPEG-2000.

Keywords: Folded reconfigurable architecture, 9/7-5/3 discrete wavelet transform (DWT), high-pass filter (HF), low-pass filter (LF), convolution scheme

Issue 6, Volume 9, June 2010

Title of the Paper:  Adder Designs using Reversible Logic Gates


Authors: P. K. Lala, J. P. Parkerson, P. Chakraborty

Abstract: A new reversible logic gate was proposed in Ref. [1]. This gate can be used to implement any classical Boolean logic function. This paper shows the application of the reversible gate in implementing ripple carry, carry skip and carry look-ahead adders. These adders are more efficient than adders implemented using Fredkin Gates

Keywords: Reversible logic, Fredkin gate, garbage output, adder design

Title of the Paper:  Development of Piezoelectric Braille Cell Control System Using Microcontroller Unit (MCU)


Authors: S. Mad Saad, F. Razaly, M. Z. Md Zain, M. Hussein, M. S. Yaacob, A. R. Musa, M. Y. Abdullah

Abstract: This paper describes about designing and developing a system for controlling piezoelectric Braille cell by using Programmable Interface Controller (PIC) microcontroller. For this purpose, PIC microcontroller is used as a controller to the system for controlling the piezoelectric Braille cell. Piezoelectric Braille cells are used in many refreshable Braille display applications. The Braille displays using piezoelectric Braille cell are able to refresh the Braille character that are read by the visually impaired by touching the dots at Braille cell. Each piezoelectric Braille cell consisting of six or eight movable pins or dots in rectangular array. The height of pins or dots in Braille cell is controlled by a piezoelectric bimorph. This will cause the pins or dots at piezoelectric Braille cell to rise or fall and therefore, create the Braille character or alphabet. Throughout the paper, the pin or dots at piezoelectric Braille cell which represent a certain Braille character is also presented. The architecture and operation of the system is discussed in detail, considering both the hardware and software elements involved. The software for programming the PIC microcontroller was written with CCS C program language. The system is developed and tested successfully. This system can be applied in the Braille Display which uses the piezoelectric Braille cell to display some of Braille characters.

Keywords: Piezoelectric Braille cell; PIC Microcontroller; CCS C program language

Title of the Paper:  Discussion on the Algorithms of a New Siphon Rain Gauge


Authors: Hong-Yang Li, Qing Li, Xiong Li, Jia-Long Song

Abstract: As the persistent rain within a short time may trigger off mud-flows and landslides which cause great losses to lives and properties, the real-time monitoring work of rainfall is very meaningful to the disaster early warning. In order to get the accurate rainfall data timely in the unattended wilderness environment, this paper presents a novel siphon rain gauge design based on a strain-type pressure sensor after an integrated consideration of the principles, operation methods, merits and faults of various types of rain gauges. This rain gauge not only keeps the advantages of the traditional siphon rain gauge such as low power and not subject to the restrictions of rainfall’s intensity, but also ensures the measurement accuracy by a pressure sensor, besides, the rainfall in the process of siphon can be compensated by the compensation algorithm. Finally, the algorithm optimized data can be transmitted over long-distance through the GSM module on the data collector, thus its scope of application will be greatly increased.

Keywords: Rain gauge, siphon, low power, long-distance transmission, curve fit

Title of the Paper:  High Precision Time and Frequency Counter for Mobile Applications


Authors: R. Szplet, Z. Jachna, K. Rozyc, J. Kalisz

Abstract: This paper presents the design, architecture, operation, and test results of a high precision time interval and frequency counter made as a small, portable instrument with USB interface. Thanks to the use of advanced time interpolators integrated in a CMOS chip, the precision (standard deviation) below 35 ps was obtained at measured time interval from 0 to 200 ms. The frequency can be measured up to 3.5 GHz. Due to the very short dead time of the counter the maximum measurement rate of 5 million measurements per second is achieved. The dedicated control software creates a user-friendly and versatile graphic interface in Windows environment. Reprogrammable CMOS technology used in the counter allows easy customizing of the instrument to match many specific applications.

Keywords: Time interval counter, time digitizer, time-to-digital converter, time interpolation, two-stage interpolation

Title of the Paper:  Eddy Current Testing in Height Measurement of Copper Cylinder and its 2D Electromagnetic Field Simulation


Authors: Yanjie Wang, Qing Li, Xiong Li

Abstract: In this article, this measurement result was found that the fluctuation amplitude of the coil’s inherent inductance L gradually reduces with increasing of frequancecy while the fluctuation amplitude of the coil’s inherent resistance R gradually increases with the increasing of frequancecy. According to the basic principle of eddy current testing, some experiments in this paper proved that the equivalent resistance R and the equivalent impedance Z of the eddy current testing equivalent circuit is unstable in repeated measurements, but the equivalent inductance L has a good stability and can be used to measure the height of copper cylinder at an appropriate frequancecy after doing a calibration between the equivalent inductance L and the height of copper cylinder. Besides, the abnormal measurement result of the equivalent inductance L was illustrated by the finite element electromagnetic field simulation when the copper cylinder is too high.

Keywords: Eddy current testing; Height measurement of copper cylinder; The finite element

Title of the Paper:  Micro-Robots used in Control of Automatic Drilling Operations


Authors: Paul Ciprian Patic, Mihaita Ardeleanu, Florin Popa

Abstract: A micro-assembly station based on a micro-robot, under an optical microscope, is one of the typical styles to practical application of the task of assembling simple micro parts, even if they are still almost at the start phase. The performance of the micro-robotic system has the potential to have an important role in such applications with reference to the transportation, handling and storage of micro objects. For that, has developed an automated system consisting of multiple drilling micro-robots. In this paper is presented a concept of control for automated micro-drilling, “cluster” type, in which several miniature robots, piezoelectric trained, are used to transport the piece of work to hold and to permit the micro-borer introduction. This type may provide some advantages having in view the accuracy and flexibility of micro fabrication.

Keywords: Micro-robot, Actuator, Micro-controller, Drill, CCD Camera, DC motor, Dynamic Modeling

Title of the Paper:  Study of the Operating States of Intrinsic Safety Barriers of the Electric Equipment Intended for Use in Atmospheres with Explosion Hazard


Authors: Niculescu Titu, Pasculescu Dragos, Pana Leon

Abstract: Electrical equipments destined to operate in potentially hazardous environments are externally connected through intrinsic safety barriers. Their gauging should observe th e safety standards in the field and it is made on grounds of a theoretical analysis, on which this paper focuses. The analysis of the safety barrier involves the consideration for three important regimes: the aperiodic regime, the aperiodic critical regim and the oscillatory regime. To this purpose, a theoretical analysis of the barrier was made, in which the uniformly distributed parameters were considered to be concentrated. For each of the situations mentioned above, the analytical expressions of the output voltage and of the current through the barrier were inferred. The analysis of the safety barrier is made in MATLAB environment, through numerical simulation in SIMULINK.

Keywords: Equipment, Explosion hazard, MATLAB, Diagram, Safety barrier

Issue 7, Volume 9, July 2010

Title of the Paper:  Bio-Inspired Visual Information Processing – The Neuromorphic Approach


Authors: W. J. Han, S. D. Kim, I. S. Han

Abstract: This paper describes the bio-inspired visual inforamtion processing by neuromorphic system, mimicking the primitive behaviour of visual cortex. The neuromorphic components are investigated for implementation of the visual signal selectivity of cortex, based on the CMOS conductance-based synaptic connections and neurons of Hodgkin-Huxley formalism. The proposed neuromorphic system exhibits the biologically plausible function mimicking the cat’s visual cortex experimentation of Hubel and Wiesel. The detection of vehicle object or human head figure demonstrates the feasibilty of vision applications.

Keywords: Neural networks, CMOS, vision, neuromorphic, visual cortex, simple cell, Hodgkin-Huxley formalism

Title of the Paper:  Design of Accurate Power Factor Measurement Approach Using FPGA-based Chip


Authors: Shu-Chen Wang, Chi-Jui Wu

Abstract: In recent years, power electronic components introduce harmonic pollution on electric power systems. It makes the traditional electromechanical power meter can not act accurately when it feeds unbalanced and harmonic loads. Power quality analysis now tends to use digital signal technology. But it is hard to avoid measurement errors in estimating power quality by digital signal technology. In this paper, it is to improve the computation errors by using FPGA. The simulation circuits were created and measured by Matlab. Then it will discuss the case of single-phase full-wave bridge rectifier loads. And then in the three-phase circuit the effective power factor, arithmetic power factor, and fundamental power factor will be compared in several simulation cases. The computation errors have been greatly reduced. In the study, the Fast Fourier Transform (FFT) is used to analyze the formula of power factor. The simulation system was modeled in Hardware Description Language (VHDL) and some novel IP (intellectual property) cores, such as CORDIC core and FFT core by the way of Bottom-Up. Design of SOC (System on a Chip) is a trend to achieve the strong and small volume in the future.

Keywords: Power Quality, Harmonic, Unbalance, FPGA, FFT

Title of the Paper:  Study on Ultrasonic Detecting Technology of Profiled Component


Authors: Yanhua Zhang, Lu Yang, Haijun Cao

Abstract: The profiled component has some structural features, such as thin wall, small diameter and corner angle on inner wall. The features make it very difficult to detect the profiled component with non-destructive examination method. According to the principle of ultrasonic creeping wave, a grouped ultrasonic detecting method is put forward to detect the standard defects in inner and outer of profiled component. Based on comparing defect echo with inner edge wave, feature extraction method of two characteristics of amplitude and time is put forward to extract defects and to eliminate the interference of inner edge wave. In order to overcome the one-sidedness disadvantage of single probe data, data fusion technology of synthesis local decisions of three probes is used to determine defects, which improves the accuracy of defect judgement. Three characteristic values of period, duration time and amplitude of echo signal are used to comprehensively evaluate the defect type. The testing results indicate that the detection method and signal processing method can meet the application requirements of accuracy and reliability, and it would have good application foreground for on-line detection.

Keywords: Profiled component, creeping wave, inner edge wave, time characteristic, amplitude characteristic, data Fusion

Title of the Paper:  Odd/Even Scroll Generation with Inductorless Chua's and Wien Bridge Oscillator Circuits


Authors: Watcharin Jantanate, Peter A. Chaiyasena, Sarawut Sujitjorn

Abstract: An inductorless Chua’s circuit, and a scroll generator are presented in this paper. The scheme employs only RCs and op-amps, and provides a very reliable generation of multiple odd and even chaotic scrolls. The design formulas and examples including simulation and practical results are illustrated. The principle has been applied successfully to generate some odd/even scrolls with the Wien bridge oscillator as illustrated by the simulation and the practical results.

Keywords: Chaos, Chua’s circuit, inductorless, Wien bride oscillator, scroll generation

Title of the Paper:  Isolated Zeta Converter: Principle of Operation and Design in Continuous Conduction Mode


Authors: Pijit Kochcha, Sarawut Sujitjorn

Abstract: The principle of operation of the zeta converter is explained in the article. Small-signal and steady-state models of the converter are presented. The design formulas for the continuous conduction mode (CCM) are given together with some design examples and simulation results. The power factor and harmonic issues are also addressed.

Keywords: Zeta converter, continuous conduction mode (CCM), harmonic, power factor

Title of the Paper:  Symbolic Equation for Linear Analog Electrical Circuits using Matlab


Authors: Zoltan Erdei, Luiza Alexandra Dicso, Liviu Neamt, Oliver Chiver

Abstract: In this paper is presented a program which generates the modified nodal equation for electric analog circuits in a symbolic, partial symbolic and numerical mode. The program is an application, made in the environment of the program MATLAB version 7.1, which has a powerful symbolic math toolbox. MATLAB is a high-performance software package dedicated for numerical analysis and graphic representations in engineering applications. In this paper we try to explore the capabilities of this program in symbolic domain.

Keywords: Analog circuits, circuit functions, symbolic equations, Matlab, netlist, modified nodal analysis

Title of the Paper:  Aircrafts' Altitude Measurement Using Pressure Information: Barometric Altitude and Density Altitude


Authors: Teodor Lucian Grigorie, Liviu Dinca, Jenica-Ileana Corcau, Otilia Grigorie

Abstract: The paper is a review of the pressure method used in the aircrafts’ altitude measurement. In a short introduction the basic methods used in aviation for altitude determination are nominated, and the importance of the barometric altitude is pointed. Further, the atmosphere stratification is presented and the general differential equation, which gives the dependence of the static pressure by the altitude, is deduced. The barometric and the hypsometric formulas for the first four atmospheric layers are developed both in the analytical and numerical forms. Also, the paper presents a method to determinate the density altitude with an electronic flight instrument system. A brief review of the flight altitudes is performed, and the calculus relations of the density altitude are developed. The first two atmospheric layers (0?11 Km and 11?20 Km) are considered. For different indicated barometric altitudes an evaluation of the density altitude, as a function of non-standards temperature variations and of dew point value, is realized.

Keywords: Standard atmosphere, atmospheric layers, barometric formula, density-altitude, evaluation

Issue 8, Volume 9, August 2010

Title of the Paper:  Second Harmonic Signal Detection on Poly[μ2-L-alanine-μ3-nitratosodium (I)] Crystals


Authors: E. Gallegos-Loya, E. Alvarez Ramos, E. Regalado, A. Duarte-Moller

Abstract: Crystals of poly (L-alanine sodium nitrate) have been grown by the slow evaporation at room temperature method. Crystal sizes of 500mm and 10 mm were obtained. UV-vis spectrum shows a wide transparent window where lake of absorption around the 532 nm. By other hand the FTIR analysis displays its functional groups corresponding to the alanine. The Single Crystal Diffraction experiment was carried out in order to determine the atomic structure and its lattice parameter. Finally as a first time the second harmonic generation was measure by using a variant of the Kurtz Perry method. The efficiency was plotted and discussed.

Keywords: L- alanine, SHG, NLO, semiorganic, alanine

Title of the Paper:  The Effect of the Output Capacitor on the Power Spectrum of the EMI Radiation, the Output Voltage Ripple and the Efficiency of a SEPIC Converter


Authors: Florian Ion, Marcel Ionel, Gabriel Predusca

Abstract: This paper presents the effect of the output capacitor on the EMI spectrum of radiation, the output voltage ripple and the efficiency of a SEPIC Converter. Two SEPIC converters were designed with LT1871 (Linear Technology) and LM2577 (National Semiconductor), for an input voltage of 4 to 16V, the output voltage of 5V, output current of 0.5A, and the switching frequency of 52kHz. The functionality of the converter was simulated in LTspice IV and OrCAD, and it was compared with the experimental results. It was measured the level of EMI spectrum, the output voltage ripple and the efficiency of the converter with different types of capacitors. An acceptable output voltage ripple, which respects the standards FCC Class A and Class B, was obtained with solid and tantalum capacitors in parallel with small MLCC capacitors. The minimum of ripple and frequency spectrum was obtained by adding a LC Filter to the output of the converter. With this filter the converter respects the standard SAE J1113.

Keywords: SMPS, SEPIC converter, output voltage ripple, converter’s efficiency, frequency spectrum

Title of the Paper:  Application of the Elliptical Trigonometry in Industrial Electronic Systems with Analyzing, Modeling and Simulating Two Functions Elliptic Mar and Elliptic Jes-x


Authors: Claude Bayeh

Abstract: In industrial electronic systems, specific electronic circuits are used to produce specific signals. In general, one circuit can?t produce more than two or three different signals; this is not the case of the Elliptical Trigonometry, in which one simple circuit can produce more than 12 different signals. In this paper, the author proposes an original control circuit for each function in order to replace the different existing circuits. The proposed circuit is the representation of an elliptical trigonometric function as “Elliptic Mar” and “Elliptic Jes-x” that are particular cases of the elliptical trigonometry. Thus, with one function, by varying the values of its parameters, the output waveform will change and can describe more than 12 different waveforms. Finally, for each function, a block diagram, a model of the circuit and a programming part are treated using Matlab/Simulink. The results of the studied circuit are presented and discussed.

Keywords: Power electronics, power converters, mathematics, trigonometry, multi form signal

Title of the Paper:  Negative Consequence of Motor Voltage Asymmetry and its Influence to the Unefficient Energy Usage


Authors: Miloje Kostic, Aleksandar Nikolic

Abstract: Analysis of the effect of unbalanced voltages on the three-phase induction motor is presented in the paper. Since the unbalanced voltage of 2%, 3.5% and 5% increase in losses could reach, in the same order, the amount of 8%, 25% and 50% of nominal power losses in the motor, it is reasonable requirement to permit voltage asymmetry ? 2%, so this is the upper limit in most national and international standards. The truth is that with a smaller load, the motor could safely work also at higher values of unbalanced voltage. The literature states that the information given previosly is determined from measurements and that they are higher than calculated values. However, it is explained here by the fact that the rotor inverse resistance is higher by 1.4 times compared to the rotor resistance in short circuit mode, since current frequency of the negative sequence in the rotor winding is two times higher (fr,NS ? 2f1=2fr,SC), i.e. it is higher for 1.41 times than corresponding values given in the literature Thus it is increasingly convinced that the requirements which are given in most appropriate standards are justified. Performed analysis show that there are some considerations that could be included in current standards. Motor operation is not generally allowed when the values of the coefficient of unbalanced voltage are U1 NS/Un ? 5%, because in the (rare) case when the direct and inverse component of the stator currents in (a) phase matching, increase of the current in that phase would be ? 1.38 times, and the increase of the losses in the windings of that phase would be ? 90%.

Keywords: Negative sequence voltage, asymetry, power losses, induction motor, energy efficiency, standard

Title of the Paper:  Role of Driver and Load Transistor (MOSFET) Parameters on Pseudo-NMOS Logic Design


Authors: Nebi Caka, Milaim Zabeli, Myzafere Limani, Qamil Kabashi

Abstract: The pseudo-NMOS logic can be used in special applications to perform special logic function. The pseudo- NMOS logic is based on designing pseudo-NMOS inverter which functions as a digital switch. During the design phase of pseudo-NMOS inverters and logic gates based on MOS technologies, it is necessary to take into consideration many parameters which characterise MOS transistors, which impact static and dynamic performances of the different logic gates. The aim of this paper is to research impact the NMOS (driver) and PMOS (active load) transistors parameters during the design phase of pseudo-NMOS inverters and in design phase pseudo-NMOS logic gates for different work cases. The results obtained emphasize the impact of each single parameter of MOSFET transistor at the low output level state, at the level values of static current at output, on the shape of the voltage transfer characteristic in the pseudo-NMOS inverter, on propagation delays during transition logic state, and impact in pseudo-NMOS logic gates. By adjusting the parameters values of NMOS and PMOS transistor it’s possible to design pseudo-NMOS inverters and pseudo-NMOS logic gate which will have acceptable performance depending on designers’ requests.

Keywords: Threshold Voltage, Driver Transistor, Active Load, Device Transconductance Parameter, Voltage Level, Low Output Level, VTC- Characteristic, Static Current, Propagation Delays, Fan-In

Issue 9, Volume 9, September 2010

Title of the Paper:  ECO-Aware Obstacle-Avoiding Routing Tree Algorithm


Authors: Jui-Hung Hung, Yao-Kai Yeh, Yu-Cheng Lin, Hsin-Hsiung Huang, Tsai-Ming Hsieh

Abstract: This study formulates a novel routing problem of engineering change order- (ECO for short) aware Steiner minimal tree with obstacles and solves it by a multiple-stage approach, including partitioning, analysis distribution of spare cells, virtual node insertion and diagonal-based routing tree construction. The objective of this paper is to construct an ECO-aware routing tree in the sense of ECO resources. The number of available spare cells near the routing tree significantly increases while minimizing the additional length compared to the original tree algorithm. To efficiently analyze, an entire chip is divided into a set of fixed-size grids and the number of spare cells in each grid is calculated. To reduce the additional length, we insert the number of user-defined virtual nodes, which represent the grids with more spare cells. Furthermore, a graph-based routing algorithm is used to construct an X-architecture tree. To further reduce total wire length, each segment in the spanning tree is transferred into the corresponding combination of vertical, horizontal and diagonal segments. Experimental results show that the number of available spare cells is increases by 66.5%, while leading to only 2.8% additional total wire length.

Keywords: Engineering change order, Obstacle-avoiding, Spare cell, Routing algorithm, X-architecture

Title of the Paper:  A High-Accuracy Electronic Pressure Transducer with a Wide Temperature Range and Single Iteration Temperature Calibration


Authors: M. J. Burke

Abstract: This article reports the development of a solid state pressure transducer for use in the measurement of blood pressure. It is intended to act as a replacement gauge for the mercury and aneroid manometers used in conventional sphygmomanometers. It measures pressure in the range 0-300mmHg (0-40kPa) with a resolution of 1mmHg (0.13kPa) and an accuracy of +1mmHg (+0.13kPa) which is displayed on a liquid crystal display. It operates from a 9V PP3 battery over a temperature range of -20 to +60oC. It is fully temperature compensated and can be calibrated in a single temperature cycle.

Keywords: Pressure Transducer, Electronic Manometer, Blood Pressure Measurement, Sphygmomanometers, Temperature Compensation

Title of the Paper:  DC Motor Behavior Analysis on Blocking the Wheels on a Railway Traction Vehicle


Authors: Ioan Baciu, Dragos Pasculescu, Corina Daniela Cuntan, Anca Iordan

Abstract: In this work are determined the current’s and voltage’s values absorbed by the d.c. motor from the componency of a 5MVA locomotive in short-circuit regime. The measures are determined by means of an analyzer of electric power’s quality on a locomotive from the periodic testing station. Are determined also the values of the harmonic distorsion factor and of the current’s and voltage’s harmonics. The acquired data recorded in the analyzer’s memory are passed afterwards into a computing system that allows their further analysis.

Keywords: Electric power’s quality, harmonic distorsion factor, voltage harmonics, current harmonics, d.c. motor, short-circuit regime

Title of the Paper:  A Simple, Efficient, and EMI-Optimized Solar Array Inverter


Authors: K. H. Edelmoser, F. A. Himmelstoss

Abstract: In the field of electrical solar power conversion efficiency is the most important topic. In common single-phase inverter applications the current of the solar array shows a remarkable ripple. This entails two significant disadvantages: Reduced over all efficiency due to dynamic maximum power point mismatch and reduced lifetime of the panels due to additional component stress. Furthermore in environments with several solar strings operating in parallel to reach the goal of a very close MPP operation, a distributed current source arrangement has to be chosen. The proposed topology discussed in this paper uses a separated active filter to fulfill the given requirements: Minimized input current ripple of the cells, string-optimized maximum power point tracking and optimal power quality of the supplying grid. The topology presented in this paper shows a remarkable improvement of the over-all efficiency as well as a significantly enhanced EMC. Consequently, it is well suited for solar power inverter applications.

Keywords: Current-Ripple-Reduction, PWM-Inverter, Solar Energy, Filter, Ripple Cancellation

Issue 10, Volume 9, October 2010

Title of the Paper:  Modeling and Performance Evaluation of UTB SGOI Devices Scalable to 22 nm Technology Node


Authors: Kiran Bailey, K. S. Gurumurthy

Abstract: There is a limit for classical CMOS devices’ scaling. So to keep the Moore’s law in force,attempts are being made to explore the possibility of designing newer devices. These attempts are in the direction of optimizing the design for high performance and low power applications. Silicon- Germanium on Insulator (SGOI) MOSFET is one such device which has got a bright future. An Attempt has been made in this paper to design 2D SGOI MOSFET using a commercial Technology CAD (TCAD) tool. Development of SGOI based Ultra thin Body (UTB) MOSFETs are proposed in this work. Device Simulations were performed for various Gate lengths, Body thicknesses, Anti punch doping and Si cap layer doping. It was found that, for a given body thickness and gate length, increasing the Silicon cap doping and anti-punch doping, the transconductance remains unchanged while Ioff, Drain Induced Barrier lowering (DIBL), Subthreshold slope and threshold voltages show improvement. Also, the devices with gate lengths 45nm, 32nm and 22nm demonstrate very good performance such as low leakage currents and good on current that are comparable to ITRS and hence can be implemented for sub-30 nm gate length devices. Device doping profiles have been optimized for the 22nm gate length CMOS devices to obtain minimum leakage and minimum static power dissipation. The performance of these devices has been evaluated by incorporating them in a Ring Oscillator and analyzing the circuit for static power dissipation and delay. The Ring oscillator consists of 3 inverter stages and with each inverter stage having a lumped capacitance of 6 MOSFETs.

Keywords: UTB MOSFETs, SGOI, Leakage currents, DIBL, Subthreshold Slope, Ring Oscillator (RO), TCAD

Title of the Paper:  Adaptive Nonuniform Sampling Delta Modulation - Practical Design Studies


Authors: Ryszard Golanski, Jacek Kolodziej

Abstract: The method of design the values of the adapted parameters for 1-bit delta modulators is the subject of the paper. The method involves systems with adapting both parameters: the quantization step sizes or/and sampling intervals. The necessary values of the sampling intervals and the step sizes should be calculated before the modulation procedure starts. All of the data of the step sizes or/and time intervals are written into the Lookup Tables. Block diagram of the ANS-DM delta modulator based on the Lookup Tables is explained. Main parts of the article are devoted to the analytical relationships on the basis of which step sizes and sampling intervals can be calculated. These formulas have been used in the program SYMMOD to computation particular values of the step sizes and sampling intervals. Two parameters adaptation in the delta modulation makes the modulator and it’s algorithm more complicated but decreases considerably the required number of sampling intervals and step sizes thus improving the quality of conversion (SNR) in relation to the solutions with only one parameter adaptation.

Keywords: Adaptive delta modulation, non-uniform sampling, Lookup Table, Jayant’s algorithm, dynamic range Lambert’s function

Title of the Paper:  Switching Power Supply Unit for an Autonomous Monitoring System


Authors: Pospisilik Martin, Adamek Milan

Abstract: There is a project of Autonomous monitoring system being solved at Tomas Bata University in Zlin. Within the framework of this project a small airship driven by ultrasonic detectors is being developed. This airship shall be capable of independent operation in an enclosed hall, bearing a camera or another monitoring system. There are several voltages needed to power the circuits of the airship. To ensure their feeding from a Li-Pol battery, a small and lightweight power supply has been designed. In this article, aspects of designing such power supply unit are analysed. Some attention is also devoted to the wider aspects of using the airships, mainly their advantages of low power consumption, and to the circumstances of employing the developed circuits.

Keywords: Airship, power supply, SMD, accumulator, propeller, monitoring

Title of the Paper:  Meteorological Parameters Effects on Solar Energy Power Generation


Authors: Safak Saglam

Abstract: As Turkey lies near the sunny belt between 36 and 42?N latitudes, most of the locations in Turkey receive abundant solar energy. The yearly average solar radiation is 3.6 kWh/m2 day, and the total yearly radiation period is approximately 2610 h. Meteorological data such as solar radiation, ambient temperature, relative humidity, wind speed, air pressure and sunshine duration are accepted as dependable and widely variable renewable energy resources. These data play a very important role in photovoltaic systems. In this study, permanent resistive load directly fed from photovoltaic panel which produce DC electrical energy. Experiments were done during 23 month period from 2008 to 2010. Permanent resistive load currents and voltages measured with power analyzer continuously during the day. At the same time meteorological parameters like outdoor temperature, air pressure, humidity, wind speed and solar radiation etc. measured and recorded with digital weather station. These measurement results compared with the graphics at the same time bases. Photovoltaic panel output power calculated with current and voltage measurements. A mathematical equation found with curve fitting method from power graphics to examine dependencies for meteorological parameters. Thus correlation between photovoltaic performance and meteorological conditions is examined for Istanbul-Goztepe.

Keywords: Meteorological Parameters, Electrical Energy, Photovoltaic System, D.C. Loads, Energy Consumption

Title of the Paper:  High Frequency Stability Semiconductor Laser Sources at 760 nm Wavelength


Authors: Bretislav Mikel, Zdenek Buchta, Josef Lazar, Ondrej Cip

Abstract: Measurement with nanometer resolution is required for the next advance in nanotechnology. Especially the non contacting methods of measurement are very .promising. We present the set-up of the laser interferometer with nanometer resolution. We developed three types of laser sources especially for using in laser interferometry and absolute laser interferometry. The standard He-Ne laser source for conventional laser interferometry techniques can be replaced by one of these tree types of laser sources. We used Vertical Surface Emitting Laser (VCSEL) and Distributed Feed-Back (DFB) laser diodes to design these laser sources. For these laser diodes we developed several methods to improvement their wavelength stability and tunability by fiber Bragg gratings (FBGs). We developed simulation method to calculation of arbitrary fiber grating (apodized, chirp etc.) with high precision by combination of methods based on layered dielectric media (LDM) and transfer matrix. On the basis of our simulations and measurements of the commercially available fiber gratings we designed a special 100 mm long fiber Bragg grating with apodization. We expect the application of the FBG to improvement of the linewidth and mode-hop free tuning range of semiconductor lasers at the wavelength 760 nm to increase resolution of fiber laser interferometer based on these diodes. We built the absolute fiber laser interferometer with Vertical Cavity Surface Emitting Laser (VCSEL) to easy employ FBG to stabilize wavelength and control the tuning range. First set up is presented.

Keywords: Laser interferometry, Absolute measurement, Tunable laser diodes, DFB laser diode, VCSEL laser diode

Title of the Paper:  Laser Interferometric Measuring System for Positioning in Nanometrology


Authors: Josef Lazar, Ondrej Cip, Martin Cizek, Jan Hrabina, Mojmir Sery, Petr Klapetek

Abstract: In this contribution we present a development of a system for dimensional nanometrology based on scanning probe microscopy techniques (primarily atomic force microscopy, AFM) for detection of sample profile combined with interferometer controlled positioning. The key goal for introduction of interferometer measurement is not only improvement of resolution but the direct traceability to the primary etalon of length. Interferometry compared to a host of other optical length measuring techniques [1,2,3...] represents the most precise measuring technique available. The system is being developed to operate at and in cooperation with the Czech metrology institute for calibration purposes and nanometrology.

Keywords: Nanometrology, Interferometry, Traceability, Local probe microscopy, Nanopositioning

Issue 11, Volume 9, November 2010

Title of the Paper:  On the Margin Effects of Commercial Bank Expansion into Securities and Insurance Activities under the Same Roof: A Mathematical Swap Approach


Authors: Jyh-Jiuan Lin,Pai-Chou Huang, Wei-Ming Hung

Abstract: The Gramm-Leach-Bliley Act (GLBA) of 1999 allows commercial bank expansion into investment banking of securities and insurance activities without limit in subsidiaries separate from commercial banks. This paper demonstrates how securities hedging, insurance underwriting, and capital regulation through the total return swap approach jointly determine the optimal bank interest margin under the same roof. We find that the bank’s interest margin and noninterest income are positively related to the bank’s securities hedging demand, and to the insurance underwriting provision, but negatively related to the bank capital requirement. We also find that the results of the bank’s noninterest income follow a similar argument as in the case of a change in interest margin. The results show that the combined production of commercial banking expansion into investment banking enhances the bank’s synergistic gains. In addition, if regulators reduce capital charges, a commercial bank will have a strong incentive to expand its investment banking activities. This suggests obvious diversification benefits from the return to investment banking under the same roof.

Keywords: Gramm-Leach-Bliley Act, Commercial Banking, Investment Banking, Total Return Swap

Title of the Paper:  Modeling Bank Interest Margin and Loan Quality under the Troubled Asset Relief Program: An Option-Pricing Approach


Authors: Jyh-Horng Lin, Jyh-Jiuan Lin, Pai-Chou Huang

Abstract: The troubled assets on U.S. banks’ books could grow to as much as $5 trillion, one Goldman Sachs analyst estimates [10]. Will setting up the Troubled Asset Relief Program (TARP) be good move for bank loan quality? The answer is yes. In an option-pricing model where the bank’s book value of loans is above its market price, an increase in loan amount sold, exactly what the TARP is meant to target, increases the bank’s interest margin. The gap where carrying value is above market price is shrinking by decreasing the risky loans held by the bank and thus the bank’s loan portfolio quality is improved.

Keywords: Troubled Asset Relief Program, Bank Interest Margin, Loan Quality

Title of the Paper:  Improving Ion-Sensitive Field-Effect Transistor Selectivity with Backpropagation Neural Network


Authors: Wan Fazlida Hanim Abdullah,, Masuri Othman, Mohd Alaudin Mohd Ali, Md Shabiul Islam

Abstract: The ion-sensitive field-effect transistor (ISFET) that is designed to detect a specific ionic activity is susceptible to interfering ions in mixed-ion environments causing the sensor to produce deceptive signals. The objective of this work is to improve the interpretation of ISFET signals in mixed-ion environments. The focus of the research is relating sensor signal to the targeted ion concentration by applying supervised neural network as post-processing stage as a method to overcome low selectivity issues. In this paper, we acquire ISFET voltage response data in potassium and ammonium mixed-ion solutions for the training of a multilayer perceptron with backpropagation algorithm. A constant-voltage constant-current readout interface circuit is applied to maintain constant bias of the sensor throughout the data collection process. Primary data from measured observations was fed to a feed-forward multilayer perceptron trained to classify levels of ionic concentrations in various levels of mixed-ion solutions. Accuracy of sensor response interpretation of ionic activity estimation is compared between with and without neural network post-processing stage. Neural network performance was also compared for voltage values with and without pre-processing voltage signals by referencing sensor response in deionized water. Further improvement of the network was approached by using an ensemble of similar structures of networks trained with backpropagation constructed using the bagging algorithm. Results show that neural network fed with dc voltage response from 4-sensor array is able to improve concentration estimation by 15% improvement compared to direct estimation based on a look-up table. Pre-processing the sensor response significantly improves the sensor signal repeatability correlation factor by 15.5% and reduces mean-square error by 98.3%, with a typical 20% improvement in output-target regression factor network performance. Averaging from ensemble system is shown to give a further 5% improvement on the output-target regression factor with consistently stable ion concentration estimations.

Keywords: Microsensors, electrochemical devices, MOSFET, sensor array, supervised learning, selectivity

Title of the Paper:  Dynamic Stability Evaluation for an Electromagnetic Contactor


Authors: Chieh-Tsung Chi, Chih-Yu Hung

Abstract: This paper aims at researching the relationship between the dynamic stability of an electromagnetic contactor (abbreviated as contactor below) and the magnetic energy stored in the contactor. Explored contactors are served as an equivalent nonlinear and time-varying inductor. Some basic and important characteristics of the contactor are theoretically researched and discussed. Several critical results are found during closing phase and voltage sag events occurred simply by using the basic definitions of passivity conditions theorem. By means of magnetic circuit analyzing method, a mathematic model and its numerical computer program of a contactor are first established in our laboratory. Therefore, some typical and important experiments such as the dynamic stability of contactor during the closing process and voltage-sag events are carried out by using this model. Later, these simulation results are compared with the experimental results for validating the correctness of this contactor model too. The final comparing results are in agreement with well. For purpose of further to know the voltage sensitivity of the experimental contactor, the CBEMA curves of contactor are used and obtained as well. Finally, the dynamic stability of the contactor during closing process and voltage sags is examined in terms of the energy stored through the simulation process of the contactor. Lots of simulation and experimental results make sure that the contactor model is correct and proposed dynamic stability evaluation method is effective.

Keywords: CBEMA curve, passivity energy, contactor, voltage sag, dynamic stability

Issue 12, Volume 9, December 2010

Title of the Paper:  Study on the Operation of a Low-Voltage AC Microgrid with Multiple Distributed Generations


Authors: Wei-Tzer Huang

Abstract: This paper aims to study the operation of a low-voltage AC microgrid with multiple distributed generations (DGs). First of all, a 400 V low-voltage AC microgrid integrated with a 30 kW microturbine generator, a 13 kW photovoltaic generation system, a 10 kW fuel cell generation system, and a 10 kVA wind turbine generator was employed as the sample system. Next, a sequential three-phase power-flow program that developed by the implicit ZBUS Gauss method was derived in this paper. Finally, the daily transformer loadings, voltage/line flow profiles, and system losses of the proposed microgrid were analyzed and discussed by the developed sequential three-phase power-flow program. The outcomes of this paper are helpful for researchers to realize the operation characteristics of AC low-voltage microgrids.

Keywords: Microgrids, Distributed Generators, Steady-State Analysis, Three-Phase Power-Flow, Distribution Systems, Line Flow

Title of the Paper:  A Standard Cell Based Synchronous Dual-Bit Adder with Embedded Carry Look-Ahead


Authors: Padmanabhan Balasubramanian, Krishnamachar Prasad, Nikos E. Mastorakis

Abstract: A novel synchronous dual-bit adder design, realized using the elements of commercial standard cell libraries is presented in this article. The adder embeds two-bit carry look-ahead generator functionality and is realized using simple and compound gates of the standard cell library. The performance of the proposed dualbit adder design is evaluated and compared vis-a-vis the conventional full adder (implemented using two half adder blocks) and the library’s full adder element, when performing 32-bit addition on the basis of the fundamental carry propagate adder topology. Based on experimentations targeting the best case process corner of the high-speed 130nm UMC CMOS cell library and the highest speed corner of the inherently power optimized 65nm STMicroelectronics CMOS standard cell library, it has been found that the proposed adder module is effective in achieving significant performance gains even in comparison with the commercial library based adder whilst facilitating reduced energy-delay product.

Keywords: Adder, High-speed, Low power, PDP, EDP, Standard cells, Semi-custom design style

Title of the Paper:  A Software Solution for Mechanical Change Measurement through Virtual Instrumentation


Authors: Nicolae Patrascoiu, Aron Poanta, Adrian Tomus, Bogdan Sochirca

Abstract: This paper presents a software solution for implementing a method to measure a displacement and angular speed for a mobile that is moving in a linear or circular direction. In order to achieve this, we determine a function for sensing the direction of movement and also we propose the algorithm through which is made the measurement. In order to implement this we use a instrument built in LabVIEW. By this algorithm is possible to use a data acquisition boards for general use, such as PCI-6024E, which has no inputs for quadrature signals with a quadrature encoder, such as E6A2-CW5C (Omron) or HEDS – 5500 (Avago Technologies) that generates this type of signals.

Keywords: Quadrature encoder, data acquisition board, algorithm, virtual instrument, measurement

Title of the Paper:  Pulse Generator Monocycle Gaussian for UWB Applications


Authors: Mohamed Dhieb, Mongi Lahiani, Hamadi Ghariani

Abstract: This paper focuses on the study and design of a simple MOS generator circuit which provides the first derivative of the Gaussian pulse from input rectangular signal. To generate wavelets required in an ultra-wideband (UWB) impulse radio, the first derivative of the Gaussian function is approximated by combining four hyperbolic tangent functions (tanh). Afterwards, four differential pairs are used. The output generator circuit is ultra short monocycle pulses about 244 ps width alternately in phase and in opposition of phase. The generated width pulse can be adjusted by changing the rise and fall time of the input signal. Simulations show that a good approximation of this waveform is possible while using integrated coefficients. A MOS transistor circuit implementation is presented and its simulation results are shown. Comparisons between theoretical and simulation tests are detailed in order to validate the design and the good functioning of the complete structure. . Furthermore, the 2.5 V voltages supply, relative to the chosen MOS 0.35µm technologies (AMS foundry), allows the reduction of the system power consumption.

Keywords: Transfer function, Hyperbolic tangent, MOS transistors differential pair, Monocycle pulses, Ring oscillator

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