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655 articles for “s-band”
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Optimization of Indium Concentration for Obtaining Enhanced Performance of 980nm InxGa1-xAs/GaAs MQW VCSELs
Abstract: AbstractIn this work, an optimization of Indium concentration of 980 nm InxGa1-xAs/GaAs MQW VCSELs is presented with the aim of improving dynamic performance of the VCSEL. An improved modulation performance is obtained by optimizing Indium concentration of x=0.2. A high modal gain and low transparency carrier density contributes to a high optical output power for In0.2Ga0.8As/GaAs MQW VCSEL. A highest modulation bandwidth of 11.625 GHz is obtained for In0.2Ga0.8As/GaAs MQW …
Published in Trends in Opto-electro & Optical Communication · Vol. 3, Issue 2, 2013 · pp. 14–21 Read article
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Improved Performance Characteristics of a Designed 1050 nm Bottom Emitting MQW VCSEL using Al0.25Ga0.22In0.53As/InP Materials
Abstract: AbstractIn this work, the design and performance characteristics of a bottom emitting Al0.25Ga0.22In0.53As/InP Multi-Quantum Well (MQW) Vertical-Cavity Surface-Emitting Lasers (VCSEL) have been presented for operation at a wavelength of 1050 nm. The transparency carrier density and bandgap energy of the QW and barrier materials are computed. An improved performance of the designed VCSEL has been obtained by selecting a material with high gain and lower transparency carrier density in the …
Published in Trends in Opto-electro & Optical Communication · Vol. 3, Issue 3, 2013 · pp. 22–30 Read article
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Past, Present and Future of Passive Optical Network
Abstract: ABSTRACTDemand for faster and cheaper access network has been rising due to the rapid growth of Internet with new generation of services and applications. Optical fiber has been envisioned for delivering broadband services for more than 30 years and becomes almost essential recently. To address the present and future bandwidth demand, broadband fiber access technologies such as Passive Optical Networks (PONs) are a potential solution. Mostly, Time Division Multiplexing (TDM) …
Published in Trends in Opto-electro & Optical Communication · Vol. 1, Issue 1-3, 2011 · pp. 16–31 Read article
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Data Transmission Through Li-fi Technology by Using Nano Arduino
Abstract: The need for wireless technology that employs Radio Frequency (RF) is increasing dramatically in today's world. These resources will soon become overloaded because of the RF spectrum's constrained bandwidth. Using the visible light spectrum is one way to address the radio frequency spectrum issue. A research area called Light-Fidelity (Li-Fi) makes advantage of the Visible Light Communication visible light band (VLC). This article describes the VLC investigation, the design process, …
Published in Trends in Opto-electro & Optical Communication · Vol. 12, Issue 3, 2022 · pp. 1–10 Read article
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A Short Survey of Data Compression Techniques for Column Oriented Databases
Abstract: AbstractColumn oriented data-stores has all values of a single column stored as a row followed by all values of the next column. Such way of storing records helps in data compression since values of the same column are of the similar type and may repeat. This paper surveys the various data compression techniques in column oriented databases. Data compression is efficiently used to save storage space and network bandwidth. It …
Published in Current Trends in Information Technology · Vol. 3, Issue 2, 2013 · pp. 1–6 Read article
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Effect of EM Wave from Mobile Phone on Skin Depth in Human Blood, Bone and Muscle
Abstract: Cell phone technology has become an integral part of day to day life and it is used not only for voice messages but also for high resolution pictures and mainly the use of Internet. When cell phones are placed near to human body, the EM radiations emitted from the phone penetrate deep inside the body. The present paper investigations have been made to estimate skin depth of electromagnetic radiations inside …
Published in Journal of Communication Engineering & Systems · Vol. 7, Issue 3, 2017 · pp. 16–20 Read article
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Optimized Performance Characteristics of a 450 nm Semiconductor Laser by Varying Differential Gain
Abstract: AbstractIn this work, the effects on the performance characteristics of a true-blue 3QW separate confinement heterostrcture edge-emitting laser are presented by varying differential gain. At the temperature of 300 K, the threshold current of the laser is . The peak material gain for the designed laser is obtained as and further used for the analysis of the performance characteristics of the designed double-heterostructure laser for the variation of differential gain. …
Published in Journal of Communication Engineering & Systems · Vol. 3, Issue 3, 2013 · pp. 26–35 Read article
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Improvement of BER in Wavelet Transform-based OFDM System with Kalman Filter
Abstract: AbstractWe know that bandwidth is the most precious commodity in all communication systems such as 2G, 3G and 4G. Each service provider is now searching how to accommodate a large number of users within a limited allocated bandwidth, In order to increase the data rate of wireless medium with higher performance, orthogonal frequency division multiplexing (OFDM) is chosen. In this paper, the bit error rate analysis (BER) of discrete wavelet …
Published in Journal of Communication Engineering & Systems · Vol. 4, Issue 1, 2014 · pp. 21–28 Read article
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Analysis of Fractal based Nested Geometries Built on Design Configurations
Abstract: AbstractFractal antenna based on the nested geometries are proposed and designed in this letter. The paper depicts the design optimization of the nested geometries for multi-rate characteristics. The antenna is fed by waveguide port. The design is obtained at the center frequency 3.5 GHz. Moreover the effect various nested elements have been observed in the geometry. The modification in geometry is introduced using pentagonal elements of the patch. The enhancement …
Published in Journal of Communication Engineering & Systems · Vol. 4, Issue 3, 2014 · pp. 9–17 Read article
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Simulation of Differential Space Time Block Coding
Abstract: AbstractIn such a coherent system, the underlying assumption is that the channel does not change during one frame of data. Thus, it can also be interpreted as the frame length is chosen such that the path gain change during one frame is negligible. This is basically the quasi-static fading assumption that we have used so far. There is a bandwidth penalty due to the number of transmitted pilot symbols. Of …
Published in Journal of Communication Engineering & Systems · Vol. 6, Issue 1, 2016 · pp. 19–25 Read article
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Performance Analysis of DWT Based OFDM System using SRRC Filter in Mobile Wimax over Fading Environment
Abstract: AbstractWavelets amid its capability to provide simultaneous information in both time and frequency domain, along with minimization of interference and improved bandwidth efficiency, is considered broadly as an efficient approach to replace fast Fourier transform (FFT) in the conventional orthogonal frequency division multiplexing (OFDM) systems. Efficient filter pulses are employed spectrally in such systems in order to mitigate the effect of inter-symbol interference (ISI) as well as satisfy the bandwidth …
Published in Journal of Communication Engineering & Systems · Vol. 7, Issue 1, 2017 · pp. 1–10 Read article
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Deployment of Fi-Wi Networks Using Teaching Learning Based Optimization Algorithm
Abstract: AbstractThe demand of bandwidth and mobility to end users is ever increasing. For fulfilling this, fiber-wireless (Fi-Wi) networks are designed by integrating the advantages of optical and wireless networks. Optical networks offer high bandwidth and stability while wireless networks offer cost efficiency and mobility. With these advantages, Fi-Wi networks also offer some challenging issues. There are four key issues in Fi-Wi networks, that are ONU placement, routing, energy saving and …
Published in Journal of Communication Engineering & Systems · Vol. 7, Issue 2, 2017 · pp. 14–26 Read article
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Comparative Study of Machine Learning Techniques for Intelligent 6G Wireless Networks
Abstract: With exponential increase in the traffic and corresponding bandwidth demand, there is an immediate requirement to serve this traffic through the high-speed wireless communication networks. To fulfil requirements of the next-generation users, it will be mandatory to resort to use of advanced physical layer solutions, spectral bands at higher frequency, and efficient software enabled intelligent algorithms. In this regard, Machine Learning (ML) algorithms will play a key role in ensuring …
Published in Journal of Communication Engineering & Systems · Vol. 11, Issue 3, 2021 · pp. 1–10 Read article
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Two Port Ring Shaped DRA Based MIMO (Multiple Input Multiple Output) Antenna for WLAN Application
Abstract: This paper presents multiple input and multiple output (MIMO) antenna which is based on dielectric resonator with very good isolation. This antenna consists of two hybrid resonator and is fed by microstrip feedline through H-Shaped aperture is cut in ground plane just below the Ring DR. Area of this antenna is 40x50 mm². Impedance bandwidth (S11<-10dB) of this antenna is 5.15 to 6.15 GHz. The radiation efficiency and total gain …
Published in Research & Reviews: A Journal of Embedded System & Applications · Vol. 7, Issue 1, 2019 · pp. 17–24 Read article
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Reconstruction Techniques for Super Resolution Using Low Resolution Images
Abstract: The aim of Super Resolution (SR) reconstruction is to restore High Resolution (HR) image using information obtained from many degraded and aliased Low Resolution (LR) images. SR is signal processing for bandwidth expansion beyond the pass band of the imaging hardware system by using spatio-temporal information available from LR images. Over last three-decade various researchers contributed in the field of SR, but all are intuitive SR mechanisms. This paper employs …
Published in Research & Reviews: A Journal of Embedded System & Applications · Vol. 9, Issue 2, 2021 · pp. 5–13 Read article
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Enhancement of Proton Density Weighted Magnetic Resonance Images using Singular Value Decomposition in Wavelet Domain
Abstract: Image enhancement techniques for low contrast medical images using Singular Value Decomposition (SVD) in Discrete Wavelet Transform domain (SVD-DWT) are proposed in the literature. However, shift sensitivity, poor directionality and a lack of phase information are the primary drawbacks of the discrete wavelet transform. This work introduces a novel method of image enhancement (SVD-SWT) using SVD in Stationary Wavelet Transform (SWT) to improve the contrast of Proton Density weighted Magnetic …
Published in Research & Reviews: A Journal of Embedded System & Applications · Vol. 10, Issue 2, 2022 · pp. 10–21 Read article
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Design of Folded Cascode Amplifier for SCL 180 nm Technology Node for Low Power Applications
Abstract: In this paper, a design and simulations of a Folded Cascode Amplifier at an SCL 180 nm Technology has been done and the different way to implement the design for a given specification has also been clearly demonstrated. The given design also clearly indicates the way to improve the various design parameters for a given specification of a circuit at this node. The way to reduce the power dissipation of …
Published in Journal Of Network security · Vol. 8, Issue 1, 2020 · pp. 22–31 Read article
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Immunologic Characteristics of Apparently Healthy Nigerians Exhibiting Abnormal SPE: A Preliminary Study
Abstract: Abnormal serum protein electrophoresis patterns have been discovered in apparently healthy Africans in Britain and Ghanaians living in Accra, Ghana. Conflicting reasons were suggested for this phenomenon. The aim of present study was to determine the prevalence and characteristics of serum protein electrophoresis (SPE) abnormalities in apparently healthy Nigerians living in Ogbomoso. Three hundred (300) apparently healthy subjects aged 20–30 years were selected for the study. SPE was performed on …
Published in Research and Reviews : A Journal of Immunology · Vol. 5, Issue 3, 2015 · pp. 1–6 Read article
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Molecular Diagnosis of Rifampicin Antibiotic Resistance in Mycobacterium Avium Subspecies Paratuberculosis Isolated from Sheep Clinical Samples
Abstract: The present study was conducted to identify parts of the rpoB gene in MAP of Indian sheep isolates. The rpoB gene (Beta sub unit of RNA polymerase) is involved in conferring the rifampicin antibiotic resistance in MAP bacteria. The resistance is due to the presence of mutations in the 81 bp variable region of the rpoB gene including C1367T and T1442C mutations identified by several workers. The study was further …
Published in Research and Reviews: A Journal of Microbiology and Virology · Vol. 12, Issue 3, 2022 · pp. 35–56 Read article
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Effect of Repetitive Transcranial Magnetic Stimulation (rTMS) on Depression and Perception of Burden of a Couple with a Cerebral Palsy Child
Abstract: Aim: To determine effect of rTMS on depression on a couple with Cerebral Palsy Child. Purpose: Parenting children with neurodevelopmental disorder is related to a higher rate of depression and anxiety, increased stress, and reduced quality of life for parents and adversely affects functioning of the parents and also hampers the quality of care being provided to the CP child. Studies have shown positive effect of rTMS on depression but …
Published in Research and Reviews : Journal of Surgery · Vol. 11, Issue 3, 2022 · pp. 28–35 Read article