scholarly journals Terahertz Shielding Properties of Carbon Black Based Polymer Nanocomposites

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 835
Author(s):  
Klaudia Zeranska-Chudek ◽  
Agnieszka Siemion ◽  
Norbert Palka ◽  
Ahmed Mdarhri ◽  
Ilham Elaboudi ◽  
...  
Keyword(s):  
Carbon Black ◽  
Absorption Coefficient ◽  
Electromagnetic Interference ◽  
Communication Systems ◽  
High Speed ◽  
Data Transfer ◽  
Terahertz Range ◽  
Radiation Shields ◽  
Shielding Properties ◽  
Electromagnetic Pollution

The majority of industry using high-speed communication systems is shifting towards higher frequencies, namely the terahertz range, to meet demands of more effective data transfer. Due to the rising number of devices working in terahertz range, effective shielding of electromagnetic interference (EMI) is required, and thus the need for novel shielding materials to reduce the electromagnetic pollution. Here, we show a study on optical and electrical properties of a series of ethylene co-butyl acrylate/carbon black (EBA/CB) composites with various CB loading. We investigate the transmittance, reflectance, shielding efficiency, absorption coefficient, refractive index and complex dielectric permittivity of the fabricated composites. Finally, we report a material that exhibits superior shielding efficiency (SE)—80 dB at 0.9 THz (14.44 vol% CB loading, 1 mm thick)—which is one of the highest SE values among non-metallic composite materials reported in the literature thus far. Importantly, 99% of the incoming radiation is absorbed by the material, significantly increasing its applicability. The absorption coefficient (α) reaches ~100 cm−1 for the samples with highest CB loading. The EBA/CB composites can be used as lightweight and flexible shielding packaging materials for electronics, as passive terahertz absorbers or as radiation shields for stealth applications.

scholarly journals Laser technologies of data transfer in aquatic environment in the organization of underwater wireless communication networks

2021 ◽  
pp. 80-85
Author(s):  
В.Л. Мартынов ◽  
В.И. Дорошенко ◽  
Н.М. Божук ◽  
Ю.Г. Ксенофонтов
Keyword(s):  
Communication Networks ◽  
Optical Communication ◽  
Aquatic Environment ◽  
Communication Systems ◽  
High Speed ◽  
Data Transfer ◽  
Open Systems ◽  
Transmission Rate ◽  
Video Data ◽  
Optical Communication Systems

Решению вопросов, связанных с телекоммуникационным оборудованием, функционирующем в водной среде, в настоящее время уделяется особое внимание. На смену традиционным подводным системам обмена информацией в гидроакустических полях приходят открытые системы её оптической передачи и приёма, базирующиеся на лазерных технологиях. Это вызвано необходимостью трансляции с высокой разрешающей способностью видеоданных, среди которых, например, может быть либо визуальное отображение подводных систем в динамике, либо результаты мониторинга объектов подводной инфраструктуры в реальном масштабе времени, либо что-то другое с учётом требований Заказчика. Канал передачи такого большого объёма информации при условии ее считывания с задаваемым качеством должен иметь пропускную способность более 1 Мбит/с. Такую высокую скорость передачи невозможно реализовать в подводных гидроакустических системах, граница технических возможностей которых на превышает 10...50 кбит/с. В аналогичной ситуации при заданных параметрах канала связи частоты несущих оптического диапазона имеют порядок 1014 Гц, что обеспечивает динамический диапазон полосы пропускания в районе 1012…1013 Гц. С учётом условия квазимонохроматичности применение гидроакустических средств для передачи видеоданных становится проблематичным, так как техническая реализация такой задачи потребует слишком большого времени. С учётом сказанного, преимуществом подводных беспроводных оптических систем связи является их высокая широкополосность, которая обеспечит высокую скорость передачи данных. В статье обосновывается целесообразность использования открытых оптических системы связи для создания высокоскоростных подводных инфотелекоммуникаций, среди которых наиболее предпочтительными являются лазерные системы. Special attention is currently paid to the solution of issues related to telecommunication equipment operating in the aquatic environment. The traditional underwater systems for the exchange of information in hydroacoustic fields are being replaced by open systems for its optical transmission and reception, based on laser technologies.This is due to the need to broadcast high-resolution video data, among which, for example, there can be either a visual display of underwater systems in dynamics, or the results of monitoring objects of underwater infrastructure in real time, or something else, taking into account the requirements of the Customer. The transmission channel of such a large amount of information, provided it is read with a specified quality, must have a bandwidth of more than 1 Mbit / s. Such a high transmission rate cannot be realized in underwater sonar systems, the technical capabilities limit of which does not exceed 10 ... 50 kbit/s. In a similar situation, given the parameters of the communication channel, the carrier frequencies of the optical range are 1014 Hz, which provides a dynamic bandwidth range about 1012…1013Hz. Taking into account the condition of quasimonochromaticity, the use of hydroacoustic means for transmitting video data becomes problematic, since the technical implementation of such a task will take too long. In view of the above, the advantage of underwater wireless optical communication systems is their high broadband, which will provide a high data transfer rate. The article substantiates the expediency of using open optical communication systems for creating high-speed underwater information telecommunications, among which the most preferable are laser systems.

scholarly journals An auto synchronization technique of unipolar MPAM signals in OFDM and its application for optical wireless communication systems

2015 ◽  
Vol 18 (3) ◽  
pp. 218-224
Author(s):  
Khoa Le Dang ◽  
Phuong Huu Nguyen ◽  
Hiroshi Ochi
Keyword(s):  
Electromagnetic Interference ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Wireless Systems ◽  
Cyclic Prefix ◽  
Wireless Communication Systems ◽  
Optical Wireless Communication ◽  
Frequency Division ◽  
Optical Wireless

Optical wireless systems have attracted attention, because they allow high-speed transmission without electromagnetic interference. Orthogonal frequency division multiplexing (OFDM) can send multiple high speed signals by using orthogonal carrier frequencies. Recently, studies have been focused on the optimal OFDM technique for optical wireless systems. When using OFDM, one important issue is determining the cyclic prefix and removing it from the frame before the receiver detects signals. In this paper, we propose a new auto synchronization technique of unipolar MPAM signals. It can remove the cyclic prefix in any sample of the OFDM frame using unipolar MPAM. It is a candidate for wideband systems and using 2-PAM or 4-PAM. The results of mathematical analysis and simulations show that it can be used for optical wireless systems.

scholarly journals Material advancement in technological development for the 5G wireless communications

2020 ◽  
Vol 9 (1) ◽  
pp. 683-699
Author(s):  
Huali Hao ◽  
David Hui ◽  
Denvid Lau
Keyword(s):  
Wireless Communications ◽  
Communication Systems ◽  
High Speed ◽  
New Technologies ◽  
Data Transfer ◽  
Technological Development ◽  
New Technology ◽  
Base Station ◽  
Electromagnetic Properties ◽  
High Speed Data

AbstractThe rapidly increasing number of mobile devices, voluminous data, and higher data rate is pushing the development of the fifth-generation (5G) wireless communications. The 5G networks are broadly characterized by three unique features: ubiquitous connectivity, extremely low latency, and very high-speed data transfer via adoption of new technology to equip future millimeter band wireless communication systems at nanoscale and massive multi-input multi-output (MIMO) with extreme base station and device densities, as well as unprecedented numbers of nanoantennas. In this article, these new technologies of 5G are presented so as to figure out the advanced requirements proposed for the nanomaterials applied to antennas in particular. Because of massive MIMO and ultra-densification technology, conventional antennas are unable to serve the new frequency for smaller sizes, and the nanoantennas are used in 5G. The nanomaterials for nanoantennas applied in wideband millimeter waves are introduced. Four types of nanomaterials including graphene, carbon nanotubes, metallic nanomaterials, and metamaterials are illustrated with a focus on their morphology and electromagnetic properties. The challenges for the commercialization of 5G and nanomaterials are also discussed. An atomistic modeling approach is proposed for the development of novel nanomaterials applied in 5G and beyond.

scholarly journals NASA Space Laser Communications System

2020 ◽  
Vol 6 (2) ◽  
pp. 51-62
Author(s):  
Radosław Bielawski ◽  
Aleksandra Radomska
Keyword(s):  
Communication Systems ◽  
Electromagnetic Waves ◽  
High Speed ◽  
Data Transfer ◽  
Space Communication ◽  
Deep Space Exploration ◽  
Laser Communications ◽  
High Speed Data ◽  
Ongoing Development ◽  
Communications System

Bidirectional space communication is a fundamental prerequisite for maintaining contact with objects performing missions in space, whether manned and unmanned. Until recently, it relied solely on the propagation of electromagnetic waves (the radio) using frequency bands dedicated for objects outside the Earth's atmosphere. However, modern space technologies are subject to ongoing development as they are being fitted with advanced communication systems. Given the constant enhancement of our technological capabilities, the traditional radio-based communication shows a glaring inadequacy and contributes to the widening of a gap between this and the high technology of on-board devices installed on modern spacecraft. The technology that complies with the up-to-date requirements of space communication is optical space communication. It is expected to provide for high-speed data transfer and increase the bandwidth several times, while ensuring immunity to common cyber threats, including jamming, spoofing and meaconing. The deployment of laser-based optical communication will not only contribute to increasing the air and space operation safety levels, but also enable deep space exploration. To this end, NASA’s Laser Communications Relay Demonstration Project (LCRD) is currently undergoing development and testing. This chapter undertakes to characterise the emerging technology with respect to its operating principles, the future scope of applications and involvement in currently conducted experiments. The results from the analysis are presented in the form of scenarios outlining possible applications of laser communication.

THE INCREASING OF DATA TRANSFER NOISE IMMUNITY IN DEPARTMENTAL COMMUNICATION SYSTEMS OF SHORT-WAVE RANGE

2018 ◽  
pp. 7-19
Author(s):  
B. G. Shadrin ◽  
◽  
D. E. Zachateyskiy ◽  
V. A. Dvoryanchikov Dvoryanchikov ◽  
◽  
...  
Keyword(s):  
Communication Systems ◽  
Noise Immunity ◽  
Data Transfer ◽  
Short Wave ◽  
Wave Range
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