Electrical Engineering

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Shiv Nadar University

The large-signal behavior of traveling wave tube amplifier for a linear beam dielectric loaded anisotropically conducting tape helix slow wave structure (SWS) is realized through a swift and reliable field analysis. Using Green’s function sequence, the field components in the SWS are designated as nonlinear functionals of electron arrival time. The electron arrival time in the beam region is formulated into a nonlinear operator in the Banach space mapping form by substituting the axial electric field component into the electron ballistic equation. The nonlinear beam–wave interaction is then obtained by determining the electron arrival time through extensive successive approximations, and thus exact electric and magnetic field components in the tape helix SWS are attained. The numerical computation of the proposed model yields definitive analytical results for the electron exit velocity, induced surface current density, power gain, conversion efficiency, and optimum interaction length. © 2017 Informa UK Limited, trading as Taylor & Francis Group.

(SoE) School of Engineering

Journal of Electromagnetic Waves and Applications

Large-signal field analysis of a linear beam travelling wave tube amplifier for the anisotropically conducting tape helix slow-wave structure supported by dielectric rods

This paper presents the modelling and analysis of graphene based monopole antennas for Terahertz (THz) Band communications in micro-networks. Graphene is used as a conductor for radiating patch and ground in monopole antenna structures. Polyimide of thickness 143 μm is used as substrate with relative permittivity of 3.5. Two types of antennas were modelled; one is narrowband resonating at 0.1 THz and the other is wideband operating in 0.030-0.117 THz band. The second antenna has broader impedance bandwidth (>10\%) in the band of operation. © 2018 IEEE.

World University root node

2018 International Conference On Advances in Communication and Computing Technology, ICACCT 2018

Graphene Based Monopole Terahertz Antennas on Polyimide Substrate

Perovskite based photovoltaic (PV) devices have gained enormous importance due to their high power conversion efficiencies and ease of fabrication (solution processing). Conventionally, flexible solar cells have been reported on substrates like PET and PEN. Corning® Willow® Glass, owing to its superior processability and oxygen and moisture barrier property, is a potential replacement for these substrates. In this work, devices fabricated on Willow Glass substrates have been subjected to bending and fatigue tests to assess their worthiness as substrates for flexible solar cells. © 2018 IEEE.

2018 4th IEEE International Conference on Emerging Electronics, ICEE 2018

Flexural and bending fatigue studies of perovskite solar cells on Willow Glass substrates

Critical Read Stability (TREAD) and Critical Writeability (TWRITE) are two SRAM metrics which can characterize the dynamic behavior of read and write operations. In this paper, the impact of NBTI on TREAD and TWRITE is shown. Worst-case use conditions are identified by varying the relative degradation of the two p-FETs. Monte-Carlo simulations using foundry models (High-k Metal Gate planar MOSFET) are performed to analyze time-zero variability for different use conditions. The dynamic metrics TREAD and TWRITE are correlated with static metrics SVNM and BWTV respectively for worst-case use conditions. Degradation trend of TREAD and TWRITE is then discussed for worst and symmetric NBTI degradation cases by varying ΔVTH. © 2018 IEEE.

INDICON 2018 - 15th IEEE India Council International Conference

Analyzing Impact of NBTI and Time-Zero Variability on Dynamic SRAM Metrics

In this letter, we report on achieving significantly high (6×) sheet charge density (ns) in MgZnO/CdZnO heterostructure, as compared with that in MgZnO/ZnO, at lower Mg (≤ 0.15) compositions in barrier MgZnO layer, with both heterostructures grown by dual ion beam sputtering technique. Buffer CdZnO and barrier MgZnO layers are probed separately to investigate carrier density in defect prone sputtered layers. Capacitance-voltage measurement and temperature-dependent Hall measurement confirm the presence of quantum confined carrier density at barrier-buffer interface, suggesting that the enhancement in carrier densities in the heterostructure over individual layers is probably due to the formation of 2-D electron gas (2-DEG). © 1980-2012 IEEE.

IEEE Electron Device Letters

Enhanced Sheet Charge Density in DIBS Grown CdO Alloyed ZnO Buffer Based Heterostructure

The operation of transistorized Marx-bank circuits (MBCs) is analyzed, and physics-based modeling is used to understand the anomalous switching behavior of the first stage single trigger avalanche transistors of MBCs at high-current-injection conditions. The role of a voltage trigger pulse having variable rise time when applied to the base terminal is investigated to model the underlying physics of the anomalous switching behavior. Experimental observations related to ultrafast anomalous switching mechanisms of trigger transistor, i.e., either primary breakdown or current mode secondary breakdown, for faster and slower base drives are presented. This demonstrates the importance of the dynamic avalanche process and reverse saturation current on the switching mechanism under high-speed base-trigger ramps for different avalanche BJTs from various manufacturers and different lots. The agreement between 2-D TCAD device simulation results and the experimental observations shows the validity of the proposed theory when the base width and mobile carrier recombination rate are used as parameters in the device simulation setup. © 1973-2012 IEEE.

IEEE Transactions on Plasma Science

Fast Ionization-Front-Induced Anomalous Switching Behavior in Trigger Bipolar Transistors of Marx-Bank Circuits under Base-Drive Conditions

This paper presents a compact triple band antenna for wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) application. The proposed antenna has a rectangular patch with rectangular ring slot and a small rectangular shape slot in a partial ground plane. The dimensions of the patch, the ground and the two slots are optimized to obtain resonance at 1.6 GHz, 2.4 GHz and 5.2GHz frequencies. © 2018 Elsevier Ltd. All rights reserved.

Materials Today: Proceedings

Triple band antenna for WLAN/WiMAX applications

Storaci-Mobile phone communication has become heart of the Global economic development over past decade. As the number of users (human as well as devices) grow exponentially with each year, there is an immense need to increase capacity and throughput with minimum possible upgradation in vast existing network. The 4G-LTE cellular network capacity can be increased by massive deployment of small cells and leveraging very high frequency bands in conjunction with a Macro cell. The presence and usage of small (Phantom) cells are dynamically controlled by a Macro cell. The connection between user equipment (UE) and small cell nodes is achieved by using control and user (C/U) planes splitted at radio link. It can achieve high capacity enhancement by massive deployment of small cells. NS-3 simulations were carried out and results shows capacity enhancement and throughput. © 2017 IEEE.

IMPACT 2017 - International Conference on Multimedia, Signal Processing and Communication Technologies

Control-A nd user-plane splitting in small cell architecture of 4G LTE-A

In this work two novel copolymers of Boron dipyrromethane (BODIPY) and Fluorene are designed, synthesized and their optoelectronics properties is reported. The polymers were designed to study the effect of the substituent at the meso position of BODIPY on the optoelectronic properties of the polymer. Changing the methyl group on the phenyl group at the meso position in the BODIPY subunit to trifluoromethyl group not only lowers the LUMO energy value but also improves the electron transport in the polymer. The polymers have also been used as electron transport material to fabricate all polymer solar cell and polymer photodetectors. © 2018 IEEE.

Effect of meso substituent on Optoelectronic Properties in BODIPY based donor acceptor Copolymers

The fundamental characteristics of metal coatings that influence heat transfer are porosity and surface roughness. It is a challenge to analyze the porosity and surface roughness due to the inadequate amount of copper per coated area. In this study, a new approach to non-invasively determine the porosity of metal films utilizing a helium pycnometer and computed micro-tomography (CMT) is presented. Furthermore, a telescope-goniometer is used to measure the surface roughness. Experiments are conducted on four varieties of thin film samples coated with copper powder using wire flame and plasma thermal spray coating methods. The porosities of the thin films were determined to be between 39 and 43%. The thermal spray coating increased the hydrophobicity of the surface and the plasma coating created super-hydrophobic surfaces. The new approach establishes that the porosity of thin films can be non-invasively determined and may also be applied to a wide variety of coated surfaces. © 2018, The Author(s).