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

In this work, an ultra-wideband multiple-input multiple-output antenna on a low-cost frame retardant (Fr-4) substrate is proposed. A complex task in designing a MIMO antenna is accomplished by using the genetic algorithm. This paper develops an improved method of converting a novel compact two-element multi-band MIMO antenna into a UWB antenna using a genetic algorithm optimizer of HFSS. The length of a typical rectangular finger-like protrusion is optimized using a genetic optimizer to resonate with the proposed MIMO in UWB frequencies. To validate the outcomes of simulation, the proposed antenna model was developed on a flame retardant 4 substrate, a decent match between the measurement and simulation is observed. These designed antennas have advantages of low cost, ease of fabrication, low profile with compact design, and operating in UWB, which covers all major commercial bands. © 2021, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

World University root node

Department of Communication Engineering

School of Electronics Engineering

Vellore Campus

Advances in Intelligent Systems and Computing

Genetic Algorithm-Based Optimization in the Improvement of Wideband Characteristics of MIMO Antenna

This paper introduces a cost-effective digital thermometer design using simple and cheap component. It has different application in various areas such as office, hospital, and industry. Especially in hospital, to overcome deterioration of medical drug, tablets, medical instruments and so on, a cost effective digital thermometer was proposed. The designed thermometer is portable and everybody can access it easily. So medical devices such as thermometer become less and less accurate which can be overcome by using digital. © 2021, Springer Nature Singapore Pte Ltd.

Lecture Notes in Electrical Engineering

A Cost-Effective Digital Thermometer

Phytochemicals, especially botanical insecticides are currently of interest because of their successful application in plant protection as biocontrol agents. Biological activity of leaf aqueous extract of ten selected medicinal plants were evaluated against the fourth-instar larvae of gram pod borer Helicoverpa armigera (H¨ubner), (Lepidoptera: Noctuidae). Antifeedant activity of leaf aqueous extracts of Abutilon indicum L., Achyranthus aspera L., Aerva lanata L., Albiziz amara (Roxb), Andrographis paniculata Ness., Cardiospermum halicacabum L., Cassia tora L., Catharanthus roseus L (G) Don., Datura metal L. and Tribulus terrestris L. were evaluated in this study. Preliminary screening after 24 h of exposure with leaf aqueous extracts of the selected plants at a concentration of 1,000 ppm exhibited significant larval mortality rate. The percentage mortality rate ranged considerably from 10.8 to 72.8. The mortality rate was observed in the decreasing order of A. paniculata > C. roseus > D. metal > A. amara > C. halicacabum > A. indicum > C. tora > T. terrestris > A. aspera >A. lanata against the larvae of H. armigera. The results imply that leaf aqueous extract of A. paniculata, C. roseus and D. metal can potentially be used as eco-friendly pest control agents against the larva of H. armigera.

Department of Biotechnology

School of Bio Sciences and Technology

Fulltext

International Journal of Scientific Research and Management

Antifeedant Activity of Leaf Aqueous Extracts of Selected Medicinal Plants on VI Instar Larva of Helicoverpa Armigera (Hubner)

A simple metamaterial absorber with ultra-thin structure has been proposed for X-band applications with enhanced absorption bandwidth. The proposed structure comprises of circular rings embedded in L-shaped resonators. This ultra-thin structure (0.0420λ 0 thick with respect to the center frequency of the operating bandwidth) exhibits wide absorption of 2.3 GHz above 90% absorptivity from 9.4 to 11.7 GHz. The designed structure was tested for different polarization for transverse electric mode under normal and oblique angles of electromagnetic wave incidence. It is polarization sensitive because of its asymmetrical design, and has diverse impacts on absorption at various incidence angles. The electromagnetic fields and surface current distributions were analysed to understand the high absorption of the presented metamaterial absorber. The proposed structure has been fabricated and the experimental responses were matched closely with the simulated responses. This metamaterial absorber will be suitable for applications like stealth technology in X-band frequencies. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.

Wireless Personal Communications

An Ultra-Thin, Bandwidth Enhanced Metamaterial Absorber for X-Band Applications

This article reports an ultra-thin, compact metamaterial absorber with wideband absorption at microwave frequencies. The proposed structure contains circular and rectangular split rings, and has thickness of 0.049λ0 with respect to the center frequency of the bandwidth. This structure provides wideband absorption of 3.84 GHz from 12.80 GHz to 16.64 GHz with 90% absorptivity and absorption peaks are observed at 13.2 GHz and 16.5 GHz. The full width half maximum of the structure is 5.48 GHz from 12.09 GHz to 17 57 GHz. The absorption mechanism and polarization behavior of the structure have to be studied. The proposed metamaterial absorber is sensitive to polarization but wideband absorption is attained only for specific normal and oblique angles of incidence, with reduced absorptivity. The structure has been fabricated, and the measured results match well with the simulation responses. The advantage of the proposed absorber is its wideband absorption with compact (8 mm × 8 mm size), ultra-thin (1 mm thick substrate) structure compared to that of the other existing microwave metamaterial absorbers. © 2018 Editura Academiei Romane.

Radioengineering

An Ultra-thin Compact Wideband Metamaterial Absorber

Now a days the people's attraction towards Automated Teller Machine(ATM) has been increasing even in rural areas. As of now the security provided by all the bank is ATM pin number. Hackers know the way to easily identify the pin number and withdraw money if they haven stolen the ATM card. Also, the Automated Teller Machine is broken and the money is stolen. To overcome these disadvantages, we propose an approach "Automated Secure Tracking System" to secure and tracking the changes in ATM. In this approach, while creating the bank account, the bank should scan the iris known (a part or movement of our eye) and fingerprint of the customer. The scanning can be done with the position of the eye movements and fingerprints identified with the shortest measurements. When the card is swiped then ATM should request the pin, scan the iris and recognize the fingerprint and then allow the customer to withdraw money. If somebody tries to break the ATM an alert message is given to the nearby police station and the ATM shutter is automatically closed. This helps in avoiding the hackers who withdraw money by stealing the ATM card and also helps the government in identifying the criminals easily. © Published under licence by IOP Publishing Ltd.

Department of Software and Systems Engineering

School of Information Technology and Engineering

Language

School of Social Science and Languages

Chennai Campus

IOP Conference Series: Materials Science and Engineering

Enhanced way of securing automated teller machine to track the misusers using secure monitor tracking analysis

This study presents a new, ultra-thin compact microwave metamaterial absorber for wideband applications. The proposed metamaterial absorber comprises an outer ring and inner split ring patches on the upper surface and metallic ground in the bottom surface. A dielectric FR4 substrate of thickness 1.6 mm was placed between the top patch and the bottom ground. The designed structure was ultra-thin of λ0/13.9 thickness with respect to the centre frequency of the bandwidth. The simulation results showed ultra-wideband absorption of 6.31 GHz from 10.36 to 16.67 GHz above 85% absorptivity, and peaks at 11.1, 13.2, 14.4, and 16.2 GHz and full width half maximum of 9.6 GHz. The mechanism of absorption for the proposed ultra-wideband metamaterial absorber was studied. Also, the polarization behavior was tested under oblique and normal angles of incidence for transverse electric polarization. Due to its asymmetrical design, the proposed structure is polarization sensitive. The designed structure was fabricated and measured, and the practical results were in good agreement with the simulation results. © 2017 Wiley Periodicals, Inc.

Microwave and Optical Technology Letters

A compact ultra-thin ultra-wideband microwave metamaterial absorber

This paper presents a design of efficient smart jammer to jam the 4G signals, specifically band 3 and band 40 which can be predominantly used in India. The MATLAB Simulink tool was used for the analysis of the circuit design. Simulink, an advanced tool gives accurate results comparable to real time analysis. The DSP toolbox of the Simulink library has been largely used to construct and view the results of the model. The main objective of this paper is to receive the LTE signals, filter band 3 and band 40, add noise and increase the amplitude of the signal. The uniqueness of this design is the use of full wave rectifier in the circuit and the trigger enabled blocks. Full wave rectifier with added circuitry acts as a trigger to the jammer which contains the noise block and the gain block. Sine wave generators were used to replicate real time signals and additional signals were added as noise. The advantage of the design is when none of the bands are detected; the output will not be generated, thus saving power. The incorporation of the detector circuit and trigger circuit ensures that power is not wasted by the jamming circuit when there signal is not detected. These jammers can be used in examination halls, conference halls and in secure location where telecommunication signals are unwanted.

VIT Unitversity

Indian Journal of Science and Technology

Design of Automated Dual Band 4G Jammer using MATLAB Simulink

In this paper, a nearly perfect metamaterial absorber is proposed with enhanced bandwidth and polarization insensitive. The proposed unit cell structure consists of outer split ring and inner asterisk shaped resonators printed on FR4 dielectric substrate. The designed metamaterial absorber gives broad bandwidth of 2.01 GHz and peak absorptivity of 99.98 and 99.94 % at 19.4 and 19.8 GHz, respectively. The simulation results prove the polarization insensitive behavior of the structure for oblique and normal incidence of the polarized waves at angles of 25° and 85°, respectively. The effective parameter is retrieved and the field distributions are studied. This metamaterial absorber is well suited for K-band applications like radar and satellite communications for uses in weather radar, imaging radar and air traffic control. © Springer India 2016.

Lecture Notes in Electrical Engineering Microelectronics, Electromagnetics and Telecommunications

Bandwidth Enhanced Nearly Perfect Metamaterial Absorber for K-Band Applications

A new design has been proposed for a single layer polarization-insensitive dual-band metamaterial absorber at C and X bands. The proposed structure consists of a periodic arrangement of a circular resonator embedded in a square resonator. A commercially available FR4 dielectric has been used as a substrate with metallic grounded bottom and imprints on the other side. This structure resonates at 5.5GHz and 8.9 GHz with absorptivity of 99.8% and 99.97%, respectively. It exhibits polarization-insensitive behaviour for Transverse Electric and Transverse Magnetic polarization under oblique and normal angles of incidence. The field distributions have been studied for better understanding of the absorption mechanism. The fabricated structure has been tested, and the experimental results are similar to the simulated ones. This polarization-insensitive metamaterial absorber with its ease of design and nearly unity absorption can be used for radar applications. © 2016, Electromagnetics Academy. All rights reserved.

Progress In Electromagnetics Research M

Design of polarization-insensitive dual band metamaterial absorber

A new design for metamaterial absorber with triple band in X band range is proposed for Radar cross section reduction in stealth technology. The proposed metamaterial absorber has the advantage of ease design. It is a three layered structure, designed with modified ring resonators printed on a dielectric material with a metal ground. By proper tuning of the geometry parameters of the structure, a triple band metamaterial absorber is achieved and it is adjusted to match the effective impedance of metamaterial absorber to the free space. Hence, there is no wave transmission, minimized reflection and the absorption rate is maximized in all the bands. The resonant frequency bands are at 7.7 GHz, 9.2 GHz and 11.1 GHz with absorption rates of 99.7%, 98% and 94% respectively. The bandwidths measured at the triple band are 0.2757 GHz, 0.311 GHz and 0.2182 GHz. The total miniaturized metamaterial absorber unit cell size is 6 mm × 12 mm × 0.705 mm. Simulation results show that the proposed absorber with triple band and with high absorption rate is well suited for Radar cross section reduction in stealth technology. © 2015 IEEE.

2015 Fifth International Conference on Advances in Computing and Communications (ICACC)

Design of New Metamaterial Absorber with Triple Band for Radar Cross Section Reduction

This article presents the design of microstrip bandstop filter for ultra-wideband applications using split ring resonator. The emerging interest and ease of design for split ring resonator using microstrip transmission line technology has lead to this research. In this paper, a compact bandstop filter is designed with single and double ring split ring resonator and is simulated using HFSS, the full wave electromagnetic simulator. This structure gives a wide stopband response. The increase in the number of rings in the split ring resonator gives a sharp cut off improving the stopband performance. Simulation results show that for the bandstop filter using double ring split ring resonator, the sharp cut off is increased to-38.5dB compared to the single ring of-34.8dB and to-23dB from-18.5dB. The microstrip bandstop filter designed using single and double ring split ring resonator with ultra-wideband of 6GHz can be used for short range ultra-high speed communications in the frequency range of 4.3 to 10.4GHz. The compact filter size is 6×6mm excluding the feed. © 2015 IEEE.

2015 International Conference on Communications and Signal Processing (ICCSP)

Design of compact ultra-wideband microstrip bandstop filter using split ring resonator

A dual band microwave metamaterial absorber using rectangle loop resonator is proposed. This metamaterial absorber of size 4 mm × 7.2 mm is designed to operate at 7 GHz and 10.7 GHz. The full wave electromagnetic simulator Ansoft HFSS is used for the simulation. The reflection coefficient, absorption rate, electric field and surface current distribution for the designed metamaterial absorber are plotted and physical mechanism of power loss is analyzed. The simulation result concludes that there is no wave transmission due to metal ground and the minimum reflection of -17.1 dB and -19.4 dB at dual band with narrow bandwidth of 0.29 GHz and 0.34 GHz respectively. From the current distribution plot, it is seen that minimum reflection due to impedance matching by the proposed structure leads to the maximum absorption peaks. Hence, 98.1% and 99% absorption of electromagnetic waves is achieved by the proposed structure at 7 GHz and 10.7 GHz respectively. This metamaterial absorber with dual band absorption in C- and X- bands is be suitable for real time applications like electromagnetic interference suppression in military vehicles, telecommunication devices and satellite communication devices. © Research India Publications.

International Journal of Applied Engineering Research

Dual band microwave metamaterial absorber using loop resonator for electromagnetic interference suppression

Objective: To determine the antioxidant activity, total phenolic and flavonoid content of Petroleum ether extract (PE), Dichloromethane extract (DCM), Ethanol extract (ET) and aqueous extract (AQ) of henna seeds. Methods: Total antioxidant assay (phosphomolybenum method), DPPH radical scavenging assay, reducing power assay and lipid peroxidation inhibition assay were used to ascertain the potential of seeds as an antioxidant. Results: In all the assays carried out ET showed a greater potential to scavenge DPPH radical, reduce MO (VI) to MO (V) complex and Fe (III) to Fe (II) and to inhibit lipid peroxidation. The IC 50 of ET was far greater than that of the standard, ascorbic acid (AS) in the lipid peroxidation assay. The activity of AQ was lesser when compared with that of ET but greater than PE and DCM. The amount of phenolics and flavonoids were present in higher amounts in ET followed by AQ. Trace amounts of phenolics were detected in PE and DCM, but the amount of flavonoids were below the detection level. The study showed that the antioxidant activity and the concentrations of phenolics and flavonoids are proportionate to each other. Conclusions: Ethanolic extract of henna seeds are efficient antioxidants, which can be utilized for further isolation of active compounds and pharmaceutical applications. {\textcopyright} 2011 Hainan Medical College.