Electronics

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Single-event transients (SETs) due to heavy-ion (HI) strikes adversely affect the electronic circuits in sub-100 nm regime in radiation environment. Time-to-digital converter (TDC) is an important electronic component in many fields such as space applications and is used for measuring time precisely as a digital value. In this study, the effect of SET due to radiation strike on 45 nm vernier-type TDC with a resolution of 7 ps is analysed using cadence spectre circuit simulator. When HI strikes the delay line of TDC close to the START/STOP pulse transition, it either widens or narrows the time interval to be measured, depending on whether it strikes the top/bottom voltage-controlled delay line (VCDL). Results show that the TDC is sensitive if the SET occurs during the transition of START/STOP pulse. Moreover, the change in the time interval occurs in a regular staircase pattern, if the VCDL is struck at all instants near the pulse transition. These errors lead to erroneous digital output and cause abrupt deviations in the staircase transfer characteristics of TDC. SETs in other constituent components of TDC such as D-flip-flop and priority encoder produces glitches which can be mitigated using existing guard gate technique. © The Institution of Engineering and Technology.

VIT Unitversity

School of Electronics Engineering

Chennai Campus

IET Circuits, Devices & Systems

Widening and narrowing of time interval due to single-event transients in 45 nm vernier-type TDC

Department of Mathematics

School of Advanced Sciences

Vellore Campus

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Fulltext

IOP Conference Series: Materials Science and Engineering

Aligned magnetic field effect on unsteady liquid film flow of Casson fluid over a stretching surface

A series of Polyethersulfone (PES)-barium chloride (BaCl2) blend ultra filtration membrane was developed by varying the BaCl2 concentration in the dope solution. Prepared membranes were subjected to membrane characterization and their performance was studied through dye rejection tests. Morphological studies through SEM and AFM showed that the composite membranes exhibited differences in morphologies, porosities and properties due to the BaCl2 addition as compared with pristine PES membrane. Addition of the inorganic modifier enhanced the hydrophilicity and water permeability of the blend membrane system. Polymer enhanced ultrafiltration of dye solutions showed that the proposed blend system had better performance in terms of flux and rejection efficiency than the pure polymer membrane. The performance of the 2 wt% BaCl2 blend membrane was more promising for application to real time dye wastewater studies. © Published under licence by IOP Publishing Ltd.

Department of Chemical Engineering

School of Chemical Engineering

Polyethersulfone – barium chloride blend ultrafiltration membranes for dye removal studies

Usage of biodiesel fuels and their blends with diesel fuel has a potential to reduce the tailpipe emissions and reduce the dependence on crude oil imports. Further, biodiesel fuels exhibit favourable greenhouse gas emission and energy balance characteristics. While fossil fuel technology is well established, the technological implications of biofuels particularly biodiesel is not clearly laid out. Hence, the objective is to provide an on-board metering control in selecting the different proportions of diesel and bio-diesel blends. An on-board fuel metering system is being developed using PID controller, stepper motors and a capacitance sensor. The accuracy was tested with the blends of propanol-1, diesel and are found to be within 1.3% error. The developed unit was tested in a twin cylinder diesel engine with biodiesel blended diesel fuel. There was a marginal increase (5%) in nitric oxide and 14% increase in smoke emission with 10% biodiesel blended diesel at part load conditions. © 2017 Published under licence by IOP Publishing Ltd.

Department of Automotive Engineering

School of Mechanical Engineering

Department of Design and Automation

Development of on-board fuel metering and sensing system

This paper deals with the extraction of RF metrics of multi-fin Tunnel FET (TFET) with the inter fin separation (IFS) scaled up to 1 nm. The structure of multi-fin TFET is designed by varying the number of fins (N) from 1 to 5. As the number of fins increases, the drive current (ID) gets multiplied and the maximum ID of 76 µA can be achieved for N = 5. Higher ID is obtained without compromising the leakage current (IOFF) which is in the range of femto amperes. For the various values of IFS, RF metrics such as intrinsic gain (A0), unity gain cut-off frequency (ft), maximum oscillation frequency (fmax), and admittance (Y) parameters are extracted for multi-fin TFETs. The results show for lesser values of IFS, higher intrinsic gain is obtained and the value does not affect as N increases. The maximum value of ft and fmax is obtained because of the electrostatic coupling between the two adjacent fins. The Y parameters are extracted at an operating frequency of 10 GHz. It can be seen that Y parameters offer better values as the number of fins and IFS increases. This is due to the larger value of gate to drain capacitance (Cgd) which occurs because of the parasitic effect for higher values of IFS. © 2017 Elsevier Ltd

Materials Science in Semiconductor Processing

RF performance enhancement in multi-fin TFETs by scaling inter fin separation

In this paper a PEVD (Polynomial Eigen Value Decomposition) based adaptive kalman filter is proposed for Acoustic Echo Cancellation (AEC) in the presence of noise. Acoustic echo is the phenomenon when the speaker listens to his own voice after some delay while speaking to his fellow mate on a call. The presence of acoustic coupling between the loudspeakers and the near-end microphone signal produces an undesired acoustic echo, which reduces the speech quality. Existing AEC system implemented adaptive kalman filter which results in less output efficiency in the noisy environment. In the proposed method, the near end speech is separated from the acoustic echo as well as from the surrounding noise by using PEVD based adaptive kalman filter. Initially mixed microphone signal is pre-processed by Polynomial Eigen Value Decomposition which strongly de-correlates the signal and also de-correlates out the noise. The pre-processed signal is passed through adaptive kalman filter for estimation of the acoustic echo. The efficiency of the output is calculated using Echo Return Loss Enhancement (ERLE). If the ERLE lies in the range of 30-40 dB indicates the good echo cancellation. The simulations show that the proposed PEVD based adaptive kalman method provides higher cancellation of echo. The simulations are being carried out in Matlab 2016a.

Department of Communication Engineering

International Journal of Intelligent Engineering and Systems

Acoustic Echo Cancellation Using PEVD Based Adaptive Kalman Filter

Traditional Dynamic Time Warping (DTW) technique find similarities between two one-dimensional time series sequence. Initially, in earlier decades, DTW was not preferred because of its computational complexity. However, due to the evolution of computing power, this has been revisited for spoken keyword detection recently. Conventional spectral features such as Mel-Frequency Cepstral Coefficients (MFCC) and contemporary wavelet features are multi-dimensional in nature which are used in speech recognition. In this work, a new strategy of DTW is proposed to work with multi-dimensional feature vector in calculating the local distance matrix. Additionally, a faster approach is specified to find the similarity in the global distance matrix. The proposed methods are evaluated with MFCC and wavelet features on a connected TIDIGITS corpus for spoken keyword detection system. Experimental results prove that there is an improvement in reduction of computational complexity compared to traditional DTW. Also, contemporary wavelet feature based spoken keyword detection system gave better detection accuracy than MFCC based spoken keyword detection system in the noisy environment.

Electrical

School of Electrical Engineering

Modified Multivariate Euclidean Dynamic Time Warping Based Spoken Keyword Detection

This letter presents design of novel annular ring crescent shape dual band and wideband antennas using T-shape stub for worldwide interoperability for microwave access (Wi-MAX) and wireless local area network (WLAN). These antennas are designed based on annular ring antenna and CPW feed. Dual band ring antenna with truncated ground plane provides a resonance at 3.5 GHz and addition of crescent shape with tuning of T-shape stub provides a second resonance at 5.8 GHz. Ground plane shape is extremely significant for impedance matching. Wide band ring antenna with crescent shape and modified T-shape stub exhibits bandwidth of 6.35 GHz from 4.75 to 11.1 GHz, further study shows that compactness of the antenna makes it suitable for active integrated antenna (AIA) application. Both dual band and wideband compact antennas are fabricated on FR4 substrate with the compact size of 28mm×26:5 mm×1:6mm. © 2017 Wiley Periodicals, Inc.

Microwave and Optical Technology Letters

CPW feed dual band and wideband antennas using crescent shape and T-shape stub for Wi-Fi and WiMAX application

Computers & Electrical Engineering

An efficient secure communication for healthcare system using wearable devices

This paper deals with the effect of structural, doping, and work function parameter variations on the Radio-Frequency metrics, unity gain cutoff frequency (ft), non-quasi static delay, intrinsic gain, and noise figure in double-gate Fin Field Effect Transistor (FinFET), junctionless FinFETs, and conventional and junctionless gate-all-around devices using Technology Computer-Aided Design simulations. This is done quantitatively by performing a simple sensitivity study experiment and screening analysis through Plackett-Burman's design of experiment approach. The individual and overall rankings of the input parameters for the devices considered are given. Gate length affects FinFETs significantly, whereas it does not affect junctionless devices. The impact of work function on the output responses is more in junctionless devices compared with that of FinFET and gate-all-around devices. Ovality in gate-all-around devices has no impact on all the output responses. Copyright © 2016 John Wiley &amp; Sons, Ltd.