Department of Electrical Engineering

Indian Institute of Technology Hyderabad (IITH) is a premier institute of science and technology established in 2008. IITH has been consistently ranked in the&nbsp;<a href="https://iith.ac.in/reports/" rel="noopener noreferrer">top 10 institutes</a>&nbsp;in India for Engineering&nbsp;<a href="https://www.nirfindia.org/2021/EngineeringRanking.html" rel="noopener noreferrer" target="_blank">according to NIRF</a>&nbsp;making it one of the most coveted schools for science and technology in the country.

IITH offers&nbsp;<a href="https://iith.ac.in/academics/under-graduate/">undergraduate programs</a>&nbsp;in all the classical engineering disciplines, applied sciences, design, as well as several modern interdisciplinary areas. Students are given a flexibility to explore a broad set of areas, and potentially pursue a minor or double major in a discipline that is not their own. Students who wish to seek a deeper understanding of their own discipline are strongly encouraged to get involved in cutting-edge research with the help of a faculty to mentor them, and earn an Honors in their own field.

The very foundation of IIT Hyderabad is based on&nbsp;<a href="https://iith.ac.in/research/">research and innovation</a>. The vibrant research culture is evident from the number of patents and publications that IITH produces consistently every year. IITH offers&nbsp;<a href="https://iith.ac.in/academics/programmes-offered/">graduate programs</a>&nbsp;at both a masters, and a doctoral level, in several diverse areas. There are separate programs for technology, design, science, and liberal arts. The&nbsp;<a href="https://iith.ac.in/academics/post-graduate/">MTech program</a>&nbsp;is offered in various modes and durations to cater to the ever-growing need of postgraduate level professionals in the country.

IITH encourages and supports&nbsp;<a href="https://iic-iith.netlify.app/index.html" rel="noopener noreferrer" target="_blank">innovation and entrepreneurship</a>&nbsp;at every stage. The minor program in entrepreneurship is open to all students of IITH, and many of the courses are offered by industrialists who are entrepreneurs themselves. There are various&nbsp;<a href="https://iith.ac.in/research/centres-incubators/">innovation centers and incubators</a>&nbsp;that promote entrepreneurship and help mentor young innovators. IITH has been very successful in building tie-ups with leading academic institutions around the globe.

IITH enjoys a very special relationship with Japanese universities and industries that goes beyond academic and research collaborations. In fact, some of the iconic buildings in IITH campus will carry the signature of Japanese architecture.

IITH creates a unique holistic ecosystem for education that offers interactive learning, a very flexible academic structure, cutting-edge research, strong industry collaboration, and entrepreneurship. This is an environment which enables students and faculty to translate their dreams into realities.

IIT Hyderabad

This article proposes a low-power reconfigurable multimode low-noise amplifier (LNA) that can be configured for multiple narrowband as well as wideband operations while providing simultaneous input matching and output load reconfigurabilty. A component sharing technique and a component-Q-aware impedance-matching technique are introduced in the proposed LNA circuit. The proposed LNA, implemented in a United Microelectronics Corporation (UMC) 0.18- \mu \text{m} CMOS process, can operate in a narrowband mode with center frequencies around 1.8, 2.1, and 2.4 GHz as well as in a wideband mode (2-5 GHz). Measured results show that the LNA has achieved 14.1, 14.5, and 14.1 dB of voltage gain, 8.5, 8.2, and 8.7 dB of noise figure (NF) in 1.8-, 2.1-, and 2.4-GHz modes, respectively. In the wideband mode, the measured gain and the NF are 14.5 and 7.8 dB, respectively. The LNA consumes 2 and 3.8 mW of power from the 1.8-V supply in the narrowband and wideband modes, respectively. © 1993-2012 IEEE.

World University root node

IEEE Transactions on Very Large Scale Integration (VLSI) Systems

A Low-Power Reconfigurable Narrowband/Wideband LNA for Cognitive Radio-Wireless Sensor Network

Fulltext

International Journal of Antennas and Propagation

Compact Antennas for Modern Communication Systems

It is well known that multi-phase induction machine drives (IMD) are best suitable for high power application compared to the conventional 3-phase IMDs. However, with the implementation of multi-phase space vector pulse width modulation (SVPWM) presented in the literature, improvement in the linear modulation region is less significant as the number of phase increases. To overcome the abovementioned limitation, this paper proposes an octadecagonal SVPWM control technique for a nine-phase induction machine. With the implementation of octadecagonal SVPWM control technique, the linear modulation region is improved by 26.03% compared to nine-phase sinusoidal pulse width modulation and 24.2S% compared to nine-phase SVPWM. In addition, the lower order dominant time harmonics in the air-gap flux are eliminated even though the phase currents of nine-phase induction machine consist of lower-order harmonics. The absence of lower-order dominant harmonics in the air-gap flux results in reduced torque pulsations of the IMD. ANSYS Maxwell simulation and experimentation results are presented to validate the proposed control technique. © 2020 IEEE.

2020 IEEE International Conference on Power Electronics, Smart Grid and Renewable Energy, PESGRE 2020

Performance Improvement of a Nine-Phase Induction Machine using Octadecagonal SVPWM Control Technique

Inverter fed induction motors play a vital role in providing reliable operation in many industrial applications. However, the probability of failure of inverter switches is higher when compared to electro-mechanical systems. As the power electronic converter is the crucial unit in the drive, the failure of a semiconductor switch might lead to the failure of the entire drive. Therefore, it is an important concern to improve the fault-tolerance of the inverters to effectively utilize the induction motor drives (IMD). This paper proposes a reconfiguration of the nine-phase IMD to operate the system under the single-leg open-switch fault condition. ANSYS Maxwell is used for the FEM analysis of the nine-phase IMD under both normal as well as fault conditions. © 2020 IEEE.

Fault-Tolerance of the Nine-Phase Induction Machine under the Open-Switch Fault Condition

An index code for broadcast channel with receiver side information is locally decodable if each receiver can decode its demand by observing only a subset of the transmitted codeword symbols instead of the entire codeword. Local decodability in index coding is known to reduce receiver complexity, improve user privacy and decrease decoding error probability in wireless fading channels. Conventional index coding solutions assume that the receivers observe the entire codeword, and as a result, for these codes the number of codeword symbols queried by a user per decoded message symbol, which we refer to as locality, could be large. In this paper, we pose the index coding problem as that of minimizing the broadcast rate for a given value of locality (or vice versa) and designing codes that achieve the optimal trade-off between locality and rate. We identify the optimal broadcast rate corresponding to the minimum possible value of locality for all single unicast problems. We present new structural properties of index codes which allow us to characterize the optimal trade-off achieved by: vector linear codes when the side information graph is a directed cycle; and scalar linear codes when the minrank of the side information graph is one less than the order of the problem. We also identify the optimal trade-off among all codes, including non-linear codes, when the side information graph is a directed 3-cycle. Finally, we present techniques to design locally decodable index codes for arbitrary single unicast problems and arbitrary values of locality. © 1963-2012 IEEE.

IEEE Transactions on Information Theory

Locally Decodable Index Codes

Low peak-to-average-power ratio (PAPR) transmissions significantly improve the cell coverage as they enable high power transmissions. A new modulation scheme, namely \pi/2- BPSK, was introduced in the Rel-15 3GPP 5G NR specifications to support low PAPR data transmissions in the uplink. However, in the existing 5G NR specifications, the reference signals employed for coherent demodulation of data symbols have higher PAPR than the data signals. This will potentially limit the cell coverage. It is, therefore, necessary to design reference signals that have low PAPR compared to the data signals. In this paper, we first present an architecture to minimize the PAPR of a binary sequence. We then present a systematic search procedure to obtain the best set of binary sequences, which, when employed for a reference signal generation, results in the best channel estimation performance. We show via simulations that the obtained binary sequences coupled with the architecture have a PAPR 2 dB smaller than the existing reference signals without compromising on the channel estimation performance. © 2020 IEEE.

2020 International Conference on COMmunication Systems and NETworkS, COMSNETS 2020

Low PAPR DMRS sequence Design for 5G-NR Uplink

Air pollution due to haphazard industrialization has become a major concern in developing countries. Yet, enforcement of related norms remains problematic because violators cannot easily be pinpointed among closely situated industrial units. Accordingly, it has become imperative to equip regulatory authorities with an economical yet accurate tool that quickly locates emission sources and estimates emission rates. Against this backdrop, we propose RESILIENT, a method for Robust Estimation of Source Information from LImited field measuremENTs, which exhibits significant statistical robustness and accuracy even when the data are collected using a low-cost error-prone sensor. In our field experiment, where ground truth was unavailable, the sources estimated to be inactive based on the complete set of measurements were found inactive (up to three decimal places of accuracy) at least 72% of the time even when estimated using just 54% of random measurements. In that setting, rate estimates of active sources were also found to be statistically robust. For direct validation of RESILIENT, we considered a separate public dataset involving 10 tracer experiments, and obtained a significant correlation coefficient of 0.89 between estimated and recorded emission rates, and that of 0.99 between predicted and measured concentration levels at sensor locations. © 2020 Statistics; Transport process; Atmosphere modeling; Air quality; Environmental analysis; Environmental assessment; Environmental impact assessment; Environmental risk assessment; Source estimation; Pollution mapping; AERMOD; Genetic algorithm; Leave-p-out cross-validation; Limited field measurements © 2020

Department of Civil Engineering

Heliyon

RESILIENT: A robust statistical method for estimating multiple VOC sources from limited field measurements

Current differential protection is simple in principle and is immune to power swings, load encroachment and mutual coupling problems. It provides simultaneous tripping at both ends of the transmission line and multi phase auto reclosing can be easily enabled because of its accuracy in determining the faulted phase and its communication channels. Conventional differential protection has certain issues to be dealt with before using it as a best alternative to distance protection for power transmission lines. Many researchers strive to improve the sensitivity of the current differential protection. Sensitivity and safety are opposing elements and increased sensitivity may sacrifice safety. In this paper, a new differential protection algorithm is proposed using the polarity of the terminal current DC transients. Different cases are studied in order to illustrate the applicability of the proposed differential approach. The proposed algorithm is able to detect high resistance faults and is not affected by line charging current, CT saturation. It improves the sensitivity without compromising the safety of the system. Simulations are carried out on 10 Bus system using PSCAD® software and obtained results are used for illustrating the efficiency of the proposed differential protection. © 2020 Elsevier B.V.

Electric Power Systems Research

A novel algorithm for improving the differential protection of power transmission system

In general, the electrical energy is transmitted from solar panel to the grid through a boost converter along with inverter. In recent times, single state converters (like Z-source inverters and split source inverters (SSI)) are being used for grid-connected solar systems for improving the conversion efficiency and voltage gain. Among the single stage converters, SSI has addition merits like lower device count, lower switch voltage stress, which is most suitable for solar applications. However, the solar system requires a higher voltage gain converter because of its low output voltage ratings. In this regard, voltage gain of conventional SSI is enhanced using switched inductor structures and it has presented in this paper for solar energy applications. This proposed single phase high gain switched inductor split source inverter (SISSI) has a higher voltage gain compared to the other conventional topologies. And also, SISSI has a reduced passive component count, lesser inductor size, capacitor size and improved efficiency than conventional topologies. The proposed SISSI has been implemented using MATLAB/Simulink for solar applications. And, the analysis is carried out for different irradiation changes. Also, the 100W prototype of SISSI was developed by using a DSP control board, IGBT switches. And, the proposed SISSI topology compared with existing ZSI, qZSI and SSI topologies in different aspects like voltage gain, passive component size, number of components and efficiency. © 2020 IEEE.

PIICON 2020 - 9th IEEE Power India International Conference

High gain switched inductor split source inverter for solar energy applications

The intriguing physics of non-Hermitian systems satisfying parity-time (PT) symmetry has spurred a surge of both theoretical and experimental research in interleaved gain-loss systems for novel photonic devices. In this work, we investigate vertically stacked GaInP PT-symmetric nanodisk resonators arranged in two-dimensional periodic lattice using full-wave numerical simulations and scattering matrix theory. The proposed dielectric metasurface supports lasing spectral singularities with asymmetric reflection and highly anisotropic far-field scattering patterns. It offers a much broader design parameter space to control wavelength, scattering direction, and efficiency of optical emission when compared to the predominantly one-dimentional (1D) or quasi-1D structures studied so far. The proposed system with Q-factor &gt;105 serves as a powerful platform for enhanced light-matter interaction by enabling extensive control of asymmetric light scattering, amplification, and unprecedented localization of electromagnetic fields. © 2020 Optical Society of America