Indonesian Journal of Electrical Engineering and Informatics (IJEEI)
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Design of FIR digital filters using Semi-ellipse window
Get PDFA fixed window function which is similar in shape to a semi-ellipse is proposed. The semi–ellipse which has its major axis to be equal to the window length and the minor axis at unity produced about 4.2 dB lower ripple ratio than the rectangular window. The proposed window function is derived from the equation of an ellipse in the explicit and parametric forms. First of all, the spectral characteristic of the proposed window is studied in terms of spectral parameters and compared with other fixed windows like Rectangular, Bartlett, Hann, Hamming and Blackman windows. The window simulation results reveal that the proposed window produced comparable spectral characteristic with existing standard fixed windows. Secondly, the paper presents the application of the proposed window in a digital filter design. The filter analysis comparison results with other fixed windows namely Bartlett, Von Hann, Hamming, and Kaiser window, an adjustable window, confirm that filter design with the proposed window exhibits good spectral characteristic, and can be used to design better filter than the Bartlett window using less than half the Bartlett’s filter length for a fixed transition width. The similicity of its coefficients formulation and design algorithm makes it a good choice for digital filter design applications
Impact of Device Parameter Variation on the Electrical Characteristic of N-type Junctionless Nanowire Transistor with High-k Dielectrics
Get PDFMetallurgical junction and thermal budget are serious constraints in scaling and performance of conventional metal-oxide-semiconductor field-effect transistor (MOSFET). To overcome this problem, junctionless nanowire field-effect transistor (JLNWFET) was introduced. In this paper, we investigate the impact of device parameter variation on the performance of n-type JLNWFET with high-k dielectrics. The electrical characteristic of JLNWFET and the inversion-mode transistor of different gate length (LG) and nanowire diameter (dNW) was compared and analyzed. Different high-k dielectrics were used to get an optimum device structure of JLNWFET. The device was simulated using SDE Tool of Sentaurus TCAD and the I-V characteristics were simulated using Sdevice Tools. Lombardi mobility model and Philips unified mobility model were applied to define its electric field and doping dependent mobility degradation. A thin-film heavily doped silicon nanowire with a gate electrode that controls the flow of current between the source and drain was used. The proposed JLNWFET exhibits high ON-state current (ION) due to the high doping concentration (ND) of 1 x 1019 cm-3 which leads to the improved ON-state to OFF-state current ratio (ION/IOFF) of about 10% than the inversion-mode device for a LG of 7 nm and the silicon dNW of 6 nm. Electrical characteristics such are drain induced barrier lowering (DIBL) and subthreshold slope (SS) were extracted which leads to low leakage current as well as a high ION/IOFF ratio. The performance was improved by introducing silicon dioxide (SiO2) with high-k dielectric materials, hafnium oxide (HfO2) and silicon nitrate (Si3N4). It was found that JLNWFET with HfO2 exhibits better electrical characteristics and performance
Multilayer Structure Technique for Improving Determination of Electromagnetic Properties of Radar Absorbers Based on Two-Layer Method and Flanged Rectangular Waveguide Probe
Get PDFThis paper presents further development of utilization of two-layer method to perform nondestructive electromagnetic properties determination of planar radar absorbers using flanged open-ended rectangular waveguide probe. A multilayer structure of three layers was proposed to improve the measured results of these parameters obtained using two-layer method. These layers were arranged such that the test material is sandwiched between two known low loss materials to provide the needed two independent reflection coefficients necessary to extract them at different conditions of testing. The proposed structure was aimed to decrease the effect of direct backing of test material by metal plate, which influences measurement accuracy if two-layer method is used. The structure permits a suitable electric field interrogation in test material and decreases the influences of both radial and surface waves. FDTD method was adapted for modeling the problem geometry to calculate the reflection coefficients since a probe with finite flange size is used. Measurements were carried out using the proposed technique to determine complex permittivity and complex permeability of several radar absorbers over X-band applications of microwaves. In comparison with both single-layer and two-layer methods results, the measured results of these parameters agreed well with the published data. by companies and literatures
Control Strategies of a Gas Turbine Generator: A Comparative Study
Get PDFGas turbine generators are commonly used in oil and gas industries due to their robustness and association with other operating systems in the combined cycles. The electrical generators may become unstable under severe load fluctuations. For these raisons, maintaining the stability is paramount to ensure continuous functioninality.This paper deals with the modeling and simulation of a single shaft gas turbine generator using the model developed by Rowen and incorporating different types of controllers, viz a Zeigler- Nichols PID controller, a Fuzzy Logic Controller (FLC), FLC-PID and finally a hybridPID/FLC/FLC-PIDcontroller. The study was undertaken under Matlab / Simulink environment with data related to an in service power plant owned by Sonatrach, Algiers, Algeria. The results show that FLC-PID and hybrid tuned controllers provide the best time domain performances
PV/Wind Hybrid Energy System, Modeling and Simulation at variable weather conditions
Get PDFThis paper presents a modeling and simulation of a grid-connected wind / PV hybrid power system under variable weather conditions. This system includes a wind turbine system, a PV system that shares a DC bus, and no battery. The paper contains an overview of the hybrid system and some previous studies; it presents a brief overview of each component used for this system. Signal distortion remains the great obstacle when connecting to the grid, so the system architecture and its proposed control are also introduced to reduce the distortion of electrical signals to an acceptable value. A simulation of the system’s operation with specific weather conditions in three different modes was performed using the MATLAB Simulink to describe the effect of these weather conditions on the production of electrical energy. Simulation results show how these weather conditions affect the operation of this hybrid system. An acceptable distortion value of the produced current signals has also been reached. These results present an evaluation of the dynamic performance of this system under the proposed working conditions. It also shows the energy exchange with the grid
PAPR reduction in OFDM system using combined MCS and DHMT precoding
Get PDFOrthogonal Frequency Division Multiplexing (OFDM) has become a preferable scheme for most high data rate wireless communication standards. However, the non-linear power amplifier effect experienced in the OFDM system has increases the peak-to-average power ratio (PAPR). This paper proposed a Median Codeword Shift (MCS) as a new solution to alleviate the effect of high PAPR. MCS takes advantage of the codeword structure and bit position changes through the manipulation of the codeword structure and permutation process to achieve a low PAPR value. Additionally, the enhanced version of MCS is also being proposed by merging MCS with the Discrete Hartley matrix transform (DHMT) precoding method to boost the PAPR reduction. Simulation results show that MCS is capable of minimizing PAPR of conventional OFDM with 24% improvement and at the same time outperform Selective Codeword Shift (SCS) with a 0.5 dB gap. A remarkable result was also achieved by MCS-DHMT with a 15.1% improvement without facing any bit error rate (BER) degradation
NARMA-L2 Controller for Five-Area Load Frequency Control
No full textThis paper investigates the load-frequency control (LFC) based on neural network for improving power system dynamic performance. In this paper an Artificial Neural Network (ANN)based controller is presented for the Load Frequency Control (LFC) of a five area interconnected power system. The controller is adaptive and is based on a nonlinear auto regressive moving average (NARMA-L2) algorithm. The working of the conventional controller and ANN based NARMA L2 controllers is simulated using MATLAB/SIMULINK package.. The Simulink link results of both the controllers are compared
Miniaturized Ring Resonator Wideband Bandpass Filter with Wide Stop Band
Get PDFIn this paper miniaturized quarter wavelength rectangular shaped multimode ring resonator bandpass filter with extended diagonal corners and internally located high impedance perturbation stubs, is proposed. Input/output open stubs are tightly coupled to the extended diagonal corners running parallel to the two sides of the ring resonator, implemented to generate wide passband and wide stop-band. Cut-off frequencies can be shifted to the higher side by increasing the length of the sides of resonator. By inserting the perturbation stubs, rectangular ring resonator produces three degenerate modes out of which first two form a wide passband. Small square patch is attached to the opposite interior corners of the ring resonator and T-shaped stub attached to the opposite longer side of the resonator are tightly coupled with feeder line to improve the return loss, insertion loss and skirt-characteristics. Shorter sides of the rectangular ring resonator are bent in U-shaped to increase the effective length of the resonator eventually the bandwidth is widened. Filter is designed and simulated for the center frequency of 3.2 GHz, bandwidth from 2.0 GHz to 4.0 GHz, on dielectric constant 3.38 and thickness 0.508 mm. Electromagnetic simulator Ansoft HFSS is used to optimize the filter dimensions
Multi-Sensor System for Land and Forest Fire Detection Application in Peatland Area
Get PDFForest fire has a dangerous impact on environments and humans because of haze and carbon emitted from it. A common technology to detect fire hotspots is to use satellite images and then process them to determine the number of hotspots and their location. However, satellite systems cannot penetrate in bad weather or cloudy condition. This research proposes a ground sensor system, which uses several sensors related to the indicators of fire, especially fire in peatland area with unique characteristics. Common parameters of fire, such as temperature, smoke, haze, and carbon dioxide, are applied in this system. Indicators are measured using special sensors. Results of every sensor are analyzed by implementing intelligent computer programming, and an algorithm to determine fire hotspots and locations is applied. The fire hotspot location and intensity determined by integrated multiple sensors are more accurate than those determined by a single sensor. Data collected from every sensor are kept in a database, and a graph is generated for reporting and recording. In case of sensor readings with parameters, potential of fire and hotspots detected can be forwarded to the representative department for corresponding actions
Performance Analysis of Montgomery Multiplier using 32nm CNTFET Technology
Get PDFIn VLSI design vacillating the parameters results in variation of critical factors like area, power and delay. The dominant sources of power dissipation in digital systems are the digital multipliers. A digital multiplier plays a major role in a mixture of arithmetic operations in digital signal processing applications hinge on add and shift algorithms. In order to accomplish high execution speed, parallel array multipliers are comprehensively put into application. The crucial drawback of these multipliers is that it exhausts more power than any other multiplier architectures. Montgomery Multiplication is the popularly used algorithm as it is the most efficient technique to perform arithmetic based calculations. A high-speed multiplier is greatly coveted for its extraordinary leverage. The primary blocks of a multiplier are basically comprised of adders. Thus, in order to attain a significant reduction in power consumption at the chip level the power utilization in adders can be decreased. To obtain desired results in performance parameters of the multiplier an efficient and dynamic adder is proposed and incorporated in the Montgomery multiplier. The Carbon Nanotube field effect transistor (CNTFET) is a promising new device that may supersede some of the fundamental limitations of a silicon based MOSFET. The architecture has been designed in 130nm and 32nm CMOS and CNTFET technology in Synopsys HSpice. The analysed parameters that are considered in determining the performance are power delay product, power and delay and comparison is made with both the technologies.The simulation results of this paper affirmed the CNTFET based Montgomery multiplier improved power consumption by 76.47% ,speed by 72.67% and overall energy by 67.76% as compared to MOSFET-based Montgomery multiplier