The current issue of the IETE Journal of Research (Vol.62, No.4, July–August 2016) contains 12 articles. These articles present on-going research and developments taking place in the broad areas of Computer Science and Engineering, Microelectronics, Power Systems and Electromagnetics.
The paper on ‘A RAM-based MAC table with two-tier security at layer 2’ presents a RAM-based media access control (MAC) table to store port numbers, instead of conventional content addressable memory based MAC table that stores both MAC addresses and associated port numbers. The given architecture provides a two-tier security at the data-link layer. It is compared using simulation studies with CAM based techniques in terms of transistor count and the consequent effect on heat dissipation and power consumption.
The paper on ‘A study of super junction trench gate IGBT with fully self-aligned fabrication technology’, presents a super junction trench gate insulated gate bipolar transistor (SJ-TGIGBT) that has reduced on-resistance and increased breakdown voltage. It is based on optimization of the fabrication technology parameters. In particular, it requires accurate control of impurity concentration of its n drift region in the trench sidewall, and tilted angle ion implantation for fine control of doped impurity. The performance is compared with non-SJ-IGBT in terms of on-resistance.
The paper titled ‘Extending parallel computing with constraint of fixed structure by adjusting graph’, considers the task of improving the performance of parallel computing for fixed system architecture. Classically, the scaling in parallel computing systems is achieved by increasing the number of computing nodes. In the given method, the weighted graph is used for this purpose. The experimental results bring out the efficiency improvement.
In the paper on ‘Hybridized gravitational search algorithm for short-term hydrothermal scheduling’, the authors present a method for solving short-term hydrothermal scheduling using a gravitational search algorithm. The given method is evaluated statistically on two test systems.
The paper on ‘Implementation aspects of logic functions using single electron threshold logic gates and hybrid SET-MOS circuits’, is concerned with the design and analysis of logic functions using single electron threshold logic gate and hybrid SET-MOS circuits. The effect of thermal fluctuations on the stability of the threshold logic circuit is reported. Also, the performances are given in terms of circuit elements, voltage levels, power consumption and delay.
In the paper ‘Improved T-shaped Gate double heterojunction AlGaN/GaN/InGaN/GaN HEMT-based wideband flat LNA’, the authors present the design of AlGaN/GaN/InGaN/GaN high electron mobility transistor (HEMT). The performance of a cascade topology of low noise amplifier (LNA) with shunt feedback technique for wideband gain using the HEMT is also given. The DC and RF advantages of the HEMT and the cascade LNA are also presented.
The following paper on ‘Multilevel codes with hierarchical set partitioning’, presents two multilevel coding schemes for improved error performance under various communication conditions. In one scheme, set partitioning of inner multilevel code is used, while in the other scheme, a partition chain is constructed with multilevel code and interblock memory.
The paper titled ‘New developments in fault analysis based on dynamical perspective’, is about the use of nonlinear dynamical system analysis for complex power systems. Two nonlinear circuits based on Lienard equation model and Chua's circuit are discussed and solved for the super stable periodic parameters of period doubling bifurcations. The solutions of the given states are relevant for understanding the behavior of complex power system analysis.
The paper on ‘Novel full-bridge PWM resonant converter: analysis and implementation’, presents a full-bridge converter for conversion of renewable energy. The design is used to reduce switching losses of switches and rectifier diodes. A fixed frequency pulse-width modulation scheme is used to generate the switching signals and regulate output voltage. The results of experiments are used to verify the theoretical analysis of performance of the given circuit.
In the paper ‘Power control in grid-connected wind energy system using diode-clamped multilevel inverter’, the authors present a method for dynamic modeling and control of real and reactive power in grid-connected variable speed wind energy conversion system for the purpose of diode-clamped multilevel inverter. The given control method is tested under different wind speed conditions, sudden load changes, and single-phase and three-phase faults. Simulation studies are given to analyze the performance of the control method.
The paper ‘Tin oxide film deposition and characterization for a chemo-resistive gas sensor’, discusses the synthesis, structural and sensitivity of tin oxide films deposited by sputtering for a gas sensor. The analysis of a doped tin oxide film is given, and gas sensitivity of the deposited layer is analyzed as function of the deposition parameters.
The paper on ‘Two-sided impedance matching for maximum wireless power transmission’, deals with the problem of maximum power transfer capability for maximizing transmission efficiency in resonant coupled wireless power transmission systems. An adaptive two-side impedance matching technique using self-tuned L-matching circuits at both transmitting and receiving sides is given for the purpose. The paper presents the theoretical and simulation-based performance evaluation.