scholarly journals Design of Helix Antenna for 9.2GHz in FEKO for FSO/RF Hybrid System Focused on Height of Helix

2018 ◽  
Vol 11 (2) ◽  
pp. 3-7
Author(s):  
Michal Márton ◽  
Ľuboš Ovseník ◽  
Ján Turán ◽  
Michal Špes ◽  
Jakub Urbanský
Keyword(s):  
Data Storage ◽  
Optical Fibers ◽  
Communication Systems ◽  
High Speed ◽  
Young Generation ◽  
Cloud Data ◽  
Weather Changes ◽  
Rf Antenna ◽  
High Level ◽  
The Impact

Abstract Nowadays we are living in the ages of expansion of communication. The young generation depends on the online communications with other. Each of the devices is purposed to communication. Cloud data storage systems are available only with stable connection. Requirements are growing up to date. The answer on these requirements: the high speed of transmission, high level of security and wide bandwidth are optical communication systems. This system offers comparable features as optical system with physical optical fibers. But it has one big drawback. It is sensitivity to weather changes. We have to make backup link for case of outages. One part of design FSO/RF system in our case contains selection of appropriate type of RF antenna. We are looking for appropriate candidate. This paper is focused on analysis of helix antenna operating in non-licensed frequency range on 9.2GHz. The point of this paper is the examination of the impact of the height of helix designed antenna.

Free Space Optical Communication System under Different Weather Conditions

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohammad Yawar Wani ◽  
Hitesh Pathak ◽  
Karamjit Kaur ◽  
Anil Kumar
Keyword(s):  
Attenuation Coefficient ◽  
Optical Communication ◽  
Free Space ◽  
Communication Systems ◽  
High Speed ◽  
Free Space Optical Communication ◽  
Free Space Optical ◽  
Wide Range ◽  
Space Optical Communication ◽  
The Impact

AbstractFree space optical communication systems (FSO’s) have surfaced as admired means of communication in the past few years. High speed of operation, low bandwidth requirements and system reliability are the major factors responsible for their wide range of applications. These communication systems use air as a medium of transmission. Since there is no component like fiber or cable, but air is only medium, the variations in atmospheric conditions play a vital role in performance of these networks. The reason behind is that the conditions like presence of humidity, haze, snowfall, rain, dust or smoke changes the attenuation coefficient of medium. The raised attenuation levels results in increased losses and need to be carefully monitored. The present work analyzes the influence of rain on the performance of FSO network in terms of quality of transmission. The paper discusses the impact of rainfall on attenuation coefficient of air. Then impact of this attenuation on network transmission is presented in terms of BER and Q-factor. In order to demonstrate the impact, BER and Q-value is calculated for 10 Gbps FSO link for clear weather and rainfall conditions.

Automatic Flaw Detector Channels Sensitivity Adjustment with the Use of an Adaptive Threshold

NDT World ◽  
2016 ◽  
Vol 19 (3) ◽  
pp. 77-80
Author(s):  
Кисляковский ◽  
Oleg Kislyakovsky ◽  
Чистякова ◽  
Olga Chistyakova ◽  
Тарабрин ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamic Range ◽  
Optimal Algorithm ◽  
Diagnostic System ◽  
Adaptive Threshold ◽  
Flaw Detector ◽  
Small Radius ◽  
Maximum Information ◽  
High Level ◽  
The Impact

Introduction. With high-speed total ultrasonic testing (UT) of the rails, the urgent task is to provide the required testing sensitivity under the impact of a significant number of adverse factors caused by the following reasons:  unstable acoustic contact;  incorrect flaw detector channel settings due to underskilled staff;  a misalignment, for example when passing a small radius curve or when rails have significant lateral wear. The listed factors lead to level changing of echo signals within a wide dynamic range as well as to echo amplitudes ratio changing of useful and noise signals. In contrast to manual testing when an operator has the possibility of multiple scanning, total rails testing by a mobile diagnostic system is fulfilled by only a single scan. The objective of the work was to develop an optimal algorithm of flaw detector channels sensitivity adjustment and formulate the reasonable requirements for a mathematical model and hardware. Method. Theoretical researches and experimental work were conducted and resulted in the development of a multichannel flaw detector for inspection of rails by mobile means. The analysis of different mathematical models has enabled the optimal algorithm for automatic channels sensitivity adjustment to be developed. Results. The developed algorithm has allowed minimizing the impact of the negative factors and compensating the sensitivity to the level that enables high-speed single-scan rails testing to be fulfilled and maximum information at a high level of reliability to be recorded. Implementation of the adaptive threshold principle has made it possible to develop and offer the technique and technology for automatic flaw detector channels sensitivity adjustment. Conclusion. The offered technique and technology can be fully put into practice with the developed flaw detector and its control software.

scholarly journals Metasurface Spiral Focusing Generators with Tunable Orbital Angular Momentum Based on Slab Silicon Nitride Waveguide and Vanadium Dioxide (VO2)

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1864
Author(s):  
Li Chen ◽  
Lin Zhao ◽  
Yuan Hao ◽  
Wenyi Liu ◽  
Yi Wu ◽  
...  
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Vanadium Dioxide ◽  
Communication Systems ◽  
High Speed ◽  
Focal Length ◽  
Polarized Light ◽  
Optical Systems ◽  
Gaussian Beams ◽  
The Impact

The metasurface spiral focusing (MSF) generator has gained attention in high-speed optical communications due to its spatial orthogonality. However, previous MSF generators only can generate a single orbital angular momentum (OAM) mode for one polarized light. Here, a MSF generator with tunable OAM is proposed and it has the ability to transform linearly polarized light (LPL), circularly polarized light or Gaussian beams into vortex beams which can carry tunable OAM at near-infrared wavelength by controlling the phase transition of vanadium dioxide (VO2). Utilizing this MSF generator, the beams can be focused on several wavelength-sized rings with efficiency as high as 76%, 32% when VO2 are in the insulating phase and in the metallic phase, respectively. Moreover, we reveal the relationship between the reflective focal length and transmissive focal length, and the latter is 2.3 times of the former. We further demonstrate the impact of Gaussian beams with different waist sizes on MSF generators: the increase in waist size produces the enhancement in spiral focusing efficiency and the decrease in size of focal ring. The MSF generator we proposed will be applicable to a variety of integrated compact optical systems, such as optical communication systems and optical trapping systems.

Enhanced Performance Analysis of 10 Gbit/s–10 GHz OFDM-Based Radio over FSO Transmission System Incorporating ODSB and OSSB Modulation Schemes

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Mehtab Singh ◽  
Vigneswaran Dhasarathan
Keyword(s):  
Performance Analysis ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Low Cost ◽  
Weather Conditions ◽  
Space Optics ◽  
Adverse Weather ◽  
Modulation Schemes ◽  
The Impact

AbstractThe exponential rise in the demand for channel bandwidth over the last few years has lead to the problem of spectrum congestion in conventional radio frequency (RF)-based wireless communication systems. Radio over free space optics (RoFSO) provides an effective solution to tackle the problem of spectrum congestion due to its many merits including license-free bandwidth, quick and low-cost installation, cost-effectiveness, and highly secure transmission links. The high-speed data transmission capabilities and immunity to electromagnetic and RF interference makes it a suitable candidate for the development of future 5 G networks. This work focuses on the designing and performance analysis of 10 Gbit/s–10 GHz orthogonal frequency division multiplexing (OFDM) based RoFSO link under the impact of different environmental effects. Also, the performance of the proposed RoFSO link has been compared for different modulation schemes viz. optical dual sideband (ODSB) and optical single sideband (OSSB). Further, we propose an enhanced detection technique deploying Square root module (SRm) at the receiver terminal for link reach enhancement under the impact of adverse weather conditions.

scholarly journals System-on-chip sensor fusion front-end self-healing design for network-on-chip digital communications

2017 ◽  
Author(s):  
Emmanuel Seaman ◽  
Jason Du
Keyword(s):  
Sensor Fusion ◽  
Data Storage ◽  
Communication Systems ◽  
High Speed ◽  
Process Variations ◽  
Cmos Technology ◽  
Network On Chip ◽  
Cmos Process ◽  
Self Healing ◽  
On Chip

With the ultra-scaling of CMOS technology, high-speed and low-power millimeter-wave communication systems for network-on-chip have been attracting more and more attentions due to the wider bandwidth and higher data rate that can meet the ever-increasing needs for multimedia, massive external data storage, or even biomedical applications. However, from manufacturing’s perspective, the circuits implementations are increasingly susceptible to fabrication process variations with the scaling of CMOS technology, which results in loss of yield rate. To solve this issue, a sensor-fusion solution is proposed in this paper by adding multiple on-chip sensors, including power detectors, temperature sensors, information envelope detectors and related filters, instrumentation amplifiers using a standard CMOS process. These sensors and detectors aim to collect critical system performance and environmental parameters, which will be utilized by a self-healing and optimization algorithm to adjust the state of system components by digitized control knobs.

scholarly journals A Comprehensive Study on the Impact of Various Nano-gratings on MSM-PDs for Enhancement in the Light Absorption

2019 ◽  
Vol 18 (1) ◽  
pp. 27-34
Author(s):  
Alif Islam ◽  
Narottam Das ◽  
Mohammad Mohiuddin Uzzal
Keyword(s):  
Light Absorption ◽  
Communication Systems ◽  
High Speed ◽  
Light Transmission ◽  
Fdtd Method ◽  
Absorption Capacity ◽  
Absorption Enhancement ◽  
Network Systems ◽  
Simulation Results ◽  
The Impact

In this paper, we have analyzed metal-semiconductor-metal photodetectors (MSM-PDs) with different nano-grating structures or shapes to improve the light absorption capacity into the device in details for high-speed communication systems and networks. The plasmonic-based MSM-PD structure demonstrates a significant improvement in light absorption capacity for the developed device compared to conventional MSM-PDs i.e., devices that have not employed the nano-gratings. The light absorption capacity of the device is varied with the variation of geometrical shapes and parameters of the nano-gratings, such as the nano-grating height, slit width and so on. These nano-grating structures are assisting in light transmission through the central slit (i.e., subwavelength apertures) efficiently, resulting in the excitation of surface plasmon polaritons (SPPs) as the incident photons interact with the nano-gratings/ nano-corrugations. This improved light transmission in the central slit along with excited SPPs results in resonant light absorption in the device. This means the light trapped inside the central slit is triggered by the SPPs to a higher order magnitude. This causes the light absorption enhancement for the device, i.e., more light is transmitted through the device instead of reflecting back to the surface. The simulation results demonstrated that the light absorption enhancement factor (LAEF) for these devices have improved dramatically due to the nano-gratings. For modeling and simulation of these devices, Opti-FDTD tool is used which is based on finite difference time domain (FDTD) method. The application of these simulated devices is in the range of 800-850-nm. The simulation results are suitable for the design of nano-structured MSM-PDs that can be used in high-speed communication systems and sensor network systems.

scholarly journals High-speed visible light communication systems based on Si-substrate LEDs with multiple superlattice interlayers

PhotoniX ◽  
2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Fangchen Hu ◽  
Shouqing Chen ◽  
Yuyi Zhang ◽  
Guoqiang Li ◽  
Peng Zou ◽  
...  
Keyword(s):  
Visible Light ◽  
Radio Frequency ◽  
Communication Systems ◽  
High Speed ◽  
Visible Light Communication ◽  
Data Rate ◽  
Si Substrate ◽  
Theoretical Derivation ◽  
Wall Plug Efficiency ◽  
The Impact

AbstractHigh-speed visible light communication (VLC), as a cutting-edge supplementary solution in 6G to traditional radio-frequency communication, is expected to address the tension between continuously increased demand of capacity and currently limited supply of radio-frequency spectrum resource. The main driver behind the high-speed VLC is the presence of light emitting diode (LED) which not only offers energy-efficient lighting, but also provides a cost-efficient alternative to the VLC transmitter with superior modulation potential. Particularly, the InGaN/GaN LED grown on Si substrate is a promising VLC transmitter to simultaneously realize effective communication and illumination by virtue of beyond 10-Gbps communication capacity and Watt-level output optical power. In previous parameter optimization of Si-substrate LED, the superlattice interlayer (SL), especially its period number, is reported to be the key factor to improve the lighting performance by enhancing the wall-plug efficiency, but few efforts were made to investigate the influence of SLs on VLC performance. Therefore, to optimize the VLC performance of Si-substrate LEDs, we for the first time investigated the impact of the SL period number on VLC system through experiments and theoretical derivation. The results show that more SL period number is related to higher signal-to-noise ratio (SNR) via improving the wall-plug efficiency. In addition, by using Levin-Campello bit and power loading technology, we achieved a record-breaking data rate of 3.37 Gbps over 1.2-m free-space VLC link under given optimal SL period number, which, to the best of our knowledge, is the highest data rate for a Si-substrate LED-based VLC system.

scholarly journals Aping Language: Historical Perspectives on the Quest for Semantics, Syntax, and Other Rarefied Properties of Human Language in the Communication of Primates and Other Animals

2021 ◽  
Vol 12 ◽  
Author(s):  
Drew Rendall
Keyword(s):  
Communication Systems ◽  
Alarm Call ◽  
Human Condition ◽  
Laboratory Research ◽  
Artificial Language ◽  
Vervet Monkeys ◽  
Evolution Of Language ◽  
Historical Perspectives ◽  
High Level ◽  
The Impact

In 1980, Robert Seyfarth, Dorothy Cheney and Peter Marler published a landmark paper in Science claiming language-like semantic communication in the alarm calls of vervet monkeys. This article and the career research program it spawned for its authors catalyzed countless other studies searching for semantics, and then also syntax and other rarefied properties of language, in the communication systems of non-human primates and other animals. It also helped bolster a parallel tradition of teaching symbolism and syntax in artificial language systems to great apes. Although the search for language rudiments in the communications of primates long predates the vervet alarm call story, it is difficult to overstate the impact of the vervet research, for it fueled field and laboratory research programs for several generations of primatologists and kept busy an equal number of philosophers, linguists, and cognitive scientists debating possible implications for the origins and evolution of language and other vaunted elements of the human condition. Now 40-years on, the original vervet alarm call findings have been revised and claims of semanticity recanted; while other evidence for semantics and syntax in the natural communications of non-humans is sparse and weak. Ultimately, we are forced to conclude that there are simply few substantive precedents in the natural communications of animals for the high-level informational and representational properties of language, nor its complex syntax. This conclusion does not mean primates cannot be taught some version of these elements of language in artificial language systems – in fact, they can. Nor does it mean there is no continuity between the natural communications of animals and humans that could inform the evolution of language – in fact, there is such continuity. It just does not lie in the specialized semantic and syntactic properties of language. In reviewing these matters, I consider why it is that primates do not evince high-level properties of language in their natural communications but why we so readily accepted that they did or should; and what lessons we might draw from that experience. In the process, I also consider why accounts of human-like characteristics in animals can be so irresistibly appealing.

scholarly journals Towards Technology Focus on Medical Information Database with Cloud Computing

2019 ◽  
Vol 8 (12) ◽  
pp. 1589-1590
Keyword(s):  
Cloud Computing ◽  
Data Storage ◽  
Data Security ◽  
Medical Information ◽  
Medical Images ◽  
Radiology Department ◽  
Negative Effects ◽  
Cloud Data ◽  
Multiple Attribute ◽  
The Impact

Today's world towards focus is very rapid growth with the cloud computing technology in and around all the fields including the medical side. Nowadays, especially in the medical field such as radiology department manage medical images with less software and hardware. In general, cloud computing work with the public, private, hybrid and community models and different types of components such as SaaS, PaaS, Iaas. Cloud storage handle a huge number of different type of data with a shared resources model. In the user side using medical image cloud data involve new issues in data security and reliability concern. In cloud data security facing when downloading sensitive medical images can touch positive and negative effects. In this paper proposed multiple attribute-based schemes resist the impact of multiple authorities. This proposed algorithm is provably efficient and secure in the authentication than existing authentication schemes in the cloud data storage.

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