The current issue of the IETE Journal of Research (Vol. 64, No. 3, May–June 2018) contains 15 articles. These articles present on-going research and developments taking place in the broad areas of Microwave Engineering, Microelectronics, Computer Science, Biomedical Engineering and Power Systems.
The paper “A 2.45 GHz harmonic suppression rectangular patch antenna with circular polarization for wireless power transfer application,” presents the design of a miniaturized proximity coupled rectangular patch antenna with circular polarization for the purpose of wireless power transfers. The design basis for getting higher harmonic suppressions is discussed. The results of simulation studies and experimental measurements of return loss characteristics for a 2.45 GHz resonating antenna are presented in the paper.
In the paper “A compact electrical modelling for top-gated doped graphene field-effect transistor,” an analytical model for top-gated doped graphene FETs for the accurate calculation of electrical parameters used in digital circuit design is presented. The quantum capacitance and threshold voltage as obtained from the available band gap and impurity concentration respectively are discussed. The model expressions for the figures of merit such as the intrinsic voltage gain, transconductance efficiency, transit frequency are presented. The comparisons of the model derived parameters and experiments are compared and inferences are drawn.
The next paper on “A compact ultra-wideband planar printed bow-tie quasi-yagi antenna with rhombus director and tapered CPS connection structure,” presents the design comprising of three wideband configurations, and the experimental study of compact ultra-wideband planar printed bow-tie quasi-yagi antenna. The relevance of a rhombus director in removing the bandwidth limitation of a microstrip quasi-Yagi antenna and design aspects to improve impedance matching are discussed. The measurements of a prototype fabricated antenna are presented and inferences are drawn from the results and their comparisons with previously reported antenna structures.
The paper titled “Accurate formula to determine resonant frequency of double sided printed dipole antenna,” gives the design of a dipole antenna with two arms printed on the opposite faces of dielectric material. The antenna configuration is discussed in terms of the high impedance bandwidth and low cross polarization specifications. The paper also gives an empirical method to predict the resonant frequency. The measured resonant frequency of a fabricated prototype is compared with the proposed empirical method.
The next paper “Binarily gapped binary insertion sorting technique,” describes the technique based on a binarily gapped binary insertion sorting processor. This is a fundamental operation in many engineering systems. It presents the method for real-time sorting of data elements for storage in RAM. The effect of light loading and increased loading of RAM on the insertion collisions and chain movements of the data elements is discussed.
The next paper on “Broadband rectenna for radio frequency energy harvesting application,” presents the design of a microstrip fed, double-sided printed monopole antenna for RF energy harvesting applications. The features include downshifting of lower cut-off with attendant bandwidth enhancement, reduction of total antenna size, and gain enhancement. The rectenna system comprising of an antenna and a rectifier consists of a resonator between the antenna and the rectifier provides impedance matching and boosting the RF signal. The paper discusses a rectenna system that is designed and tested to provide good RF-to-DC conversion efficiency across the band.
The next paper titled “Elimination of chaotic Ferro-resonant oscillations originated from TCSC in the capacitor voltage transformer,” is concerned with the study of thyristor controlled series capacitors (TCSC) for Ferro-resonance in capacitor voltage transformers. TCSC is useful in quickly changing the impedance of a transmission line. The nonlinear dynamics of chaotic Ferro-resonant oscillations are analyzed using bifurcation theory in the paper. A method to limit these chaotic oscillations is given for the purpose of reducing thermal and insulation related problems.
In “Four element planar MIMO antenna design for long-term evolution operation,” the design of a 2 × 2 LTE MIMO antenna for wireless applications is given that combines the effect of pattern and space diversity techniques. The design caters to compact size and return loss and isolation performance that are optimized using particle swarm method. An antenna is fabricated and its properties are measured. The diversity performance is also given in terms of peak gain, envelope correlation coefficient, mean effective gain and directivity.
The next paper on “Low noise amplifier synthesis using multidimensional MLP neural network,” gives an automated method to determine the parameters of a low noise amplifier for RF applications for given design specifications. The method is based on simulations using neural networks that produces a set of design parameters for which HSPICE is used to derive the corresponding design specifications such as input and output return loss, power gain, reverse isolation, noise figure, center frequency and others. The neural network is optimized using the differences between the derived specifications and desired ones.
In “Non-identical rectangular microstrip antenna arrays for amplitude tapering,” the authors give the design method of an antenna array with amplitude shaping to reduce the first side lobe level in a rectangular microstrip antenna. The given method removes the requirement of feed network with unequal power division. Different arrays are analyzed with the given design method, and a symmetric corporate-fed 8-element array is designed and fabricated for which the simulation results and measurements are compared and inferences are drawn.
The paper titled “Optimization approaches for core mapping on networks on chip,” presents a method to map tasks to cores to minimize power consumption and optimize the network on chip (NoC) performance. A NoC is used to address the interconnection communication issues on a system on chip. This is done by a linearized model of quadratic assignment problem, and through the use of two meta-heuristic algorithms to derive the mapping. The performance of the linearized method is compared with other meta-heuristic approaches in terms of power dissipation and performance of the NoC and inferences are drawn.
The next paper on “P300 detection with brain-computer interface application using PCA and ensemble of weighted SVMs,” is concerned with the development of a brain-computer interface for disabled persons who are unable to communicate due to severe motor disabilities or neuro-muscular impairments. The P300 signal of the brain from EEG measurement is used to detect the character using a SVM classifier. The feature vector are subjected to PCA analysis before classification. The performance results obtained are also compared with other reported results.
The paper on “Peak-to-average-power-ratio (PAPR) reduction methods with wavelet transform in MIMO-OFDM,” addresses the problem of large PAPR in MIMO-OFDM systems. The methods of stochastic selective mapping and partial transmit sequence are investigated. A wavelet transform based analysis is studied in the paper and is proposed as an alternative to the Fourier analysis.
The paper on “Performance evaluation of digital comparator using different logic styles,” presents the design of a two-bit digital comparator using different logic techniques such as transmission gate login, half address logic, X-E logic and the proposed transmission gate logic techniques. The power consumption, propagation delay and transistor count in the respective designs are compared based on simulation of the designs on EDA tanner tool for 45-nanometer technology and at 0.7V supply voltage.
The paper on “Validating analytical model for steady-state can losses in a canned permanent magnet motor,” is concerned with the design of canned permanent magnet motor instead of conventional motor pump for handling toxic, dangerous and corrosive liquids. It gives the EM simulation analysis in terms of magnetic flux distribution in both sealing can and air gap, for predicting the can losses of the motors and its steady-state performance validation is described.
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Notes on contributors
Shiban K Koul
Shiban K Koul is Dr. R. P. Shenoy Astra Microwave Chair Professor at the Indian Institute of Technology, Delhi. He served as Deputy Director (Strategy and Planning) at IIT Delhi from 2012--2016. Currently, he is the Mentor Deputy Director (Strategy & Planning, International affairs and R&D) at IIT Jammu. He is also the Chairman of Astra Microwave Products Limited, Hyderabad. His research interests include: RF MEMS, High Frequency Wireless Communication, Microwave Engineering, Microwave Passive and Active Circuits, Device modeling, Millimeter wave IC design and Reconfigurable microwave circuits including antennas. Completed 34 major sponsored projects, 52 consultancy projects and 56 Technology Development Projects. Authored 361 Papers, 8 state-of-the art books and 3 book Chapters. He holds 10 patents and 6 copyrights. He is a Fellow of IEEE, INAE and IETE. He is the Chief Editor of IETE Journal of Research, Associate Editor of the International Journal of Microwave and Wireless Technologies, Cambridge University Press. He served as a Distinguished Microwave Lecturer of IEEE MTT-S for the period 2012--2014. Recipient of numerous awards including IEEE MTT Society Distinguished Educator Award (2014); Teaching Excellence Award (2012) from IIT Delhi; Award for contributions made to the growth of smart material technology (2012) by the ISSS, Bangalore, Vasvik Award (2012) for the contributions made to the area of Information, Communication Technology (ICT) and M N Saha Memorial Award (2013) from IETE. E-mail: [email protected]