ELECTRICAL IMMUNITY CHARACTERISTICS OF MULTI-PAIR LAN CABLES

2021 ◽  
Author(s):  
И.С. ШЕРСТНИКОВ ◽  
В.В. СМИРНОВА ◽  
В.Б. ПОПОВ
Keyword(s):  
Noise Immunity ◽  
Experimental Studies ◽  
Electrical Characteristics ◽  
Frequency Range ◽  
Protective Polymer

Приводятся результаты экспериментальных исследованийпомехозащищенности цепей многопарных LAN-кабелей вдиапазоне частот до 100 МГц Показано, что разработанный комплекс мероприятий по технологии скрутки кабельного сердечника, наложению на него экрана и защитной полимерной оболочки позволяет обеспечить выполнение норм на электрические характеристики помехозащищенности цепей кабеля, отвечающих требованиям категории 5е. The results of experimental studies of noise immunity of multipair LAN-cable circuits in the frequency range up to 100 MHz are presented. It is shown that the developed set of measures for the technology of twisting the cable core and applying a screen and a protective polymer sheath on it made it possible to ensure compliance with the standards for the electrical characteristics of noise immunity of cable circuits that meet the requirements of category 5e.

scholarly journals STUDY OF PROCESSES OF PRESSURE AND IMPULSE FREQUENCY INFLUENCE ON PENETRATION OF LIQUIDS IN THE SAND SAMPLES

2016 ◽  
pp. 120-125
Author(s):  
M. Ya. Habibullin ◽  
R. R. Shangareyev
Keyword(s):  
Experimental Data ◽  
Oil Recovery ◽  
Pressure Fluctuations ◽  
Experimental Studies ◽  
Regression Equations ◽  
Linear Variation ◽  
Frequency Range ◽  
Impulse Frequency ◽  
Overburden Pressure

The article deals with the issues related to the hydrocarbon reservoirs oil recovery enhancement. It describes the bench laboratory experimental studies. The results obtained during determination of fluid leakage through the rock samples and the amount of absorption of pressure fluctuations at various regime parameters are presented. Using the experimental data the regression analysis was performed on the basis of which the qualitative correlations between factorial and resultant features were identified. Using the regression equations the graphic relations were constructed. It was found that with increasing the oscillation frequency of the fluid the amount of fluid passing through the sample of porous medium increased, with the highest value of q reached at the frequency range of 600 ... 1000 Hz. With increase in the oscillations penetration depth the absorption of the amplitude of the pressure fluctuations corresponds to the linear decrease, and with the overburden pressure increase the linear variation of absorption is distorted.

scholarly journals Theoretical and experimental studies of highly selective planar two-dimensional Bragg structures based on dielectric waveguides in the terahertz frequency range

2019 ◽  
Vol 30 ◽  
pp. 07009
Author(s):  
Naum Ginzburg ◽  
Nikolay Peskov ◽  
Vladislav Zaslavsky ◽  
Ekaterina Kocharovskaya ◽  
Andrey Malkin ◽  
...  
Keyword(s):  
Bragg Reflection ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Dielectric Waveguides ◽  
Two Dimensional ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Frequency Range ◽  
Three Dimensional Modeling ◽  
Bragg Structures

Based on theoretical approach and three-dimensional modeling using the CST Microwave Studio code, planar dielectric two-dimensional Bragg structures in terahertz frequency range were developed and manufactured. Proof-of-principle electrodynamic experiments on the “cold” testing of these structures were carried out. It is shown that the experimental results are in good agreement with the theoretical predicts, including the existence of the highest Q mode inside the Bragg reflection band in the absence of periodicity defects.

scholarly journals IDENTIFICATION OF NORMAL WAVES FORMING A SOUND FIELD IN A SHALLOW SEA AT THE INFRASONIC FREQUENCY RANGE. Part II

2020 ◽  
Author(s):  
С.Б. Касаткин
Keyword(s):  
Experimental Studies ◽  
Sound Field ◽  
Noise Signal ◽  
Energy Structure ◽  
Frequency Range ◽  
Field Zone ◽  
Normal Waves ◽  
Infrasonic Frequency ◽  
Scholte Waves ◽  
Scholte Wave

Анализируются результаты экспериментальных исследований звукового поля, зарегистрированного комбинированными приемниками, образующими вертикально ориентированную двухэлементную антенну. Звуковое поле формировалось дискретными составляющими вально-лопастного звукоряда шумового сигнала НИС «Юрий Молоков» в инфразвуковом диапазоне частот 2–20 Гц, а также буксируемым низкочастотным излучателем полигармонического сигнала в диапазоне частот 30–60 Гц. Глубина моря и рабочий диапазон частот 2–20 Гц исключали возможность возбуждения нормальных волн дискретного спектра в модельном волноводе Пекериса в этом диапазоне частот. По результатам спектрального анализа шумового сигнала получена оценка потенциальной помехоустойчивости комбинированного приемника при использовании полного набора информативных параметров, характеризующих энергетическую структуру звукового поля. По результатам анализа вертикальной структуры звукового поля в инфразвуковом диапазоне частот был сделан вывод о том, что звуковое поле сформировано неоднородными нормальными волнами Шолте, регулярной и обобщенной (гибридной). В дальней зоне источника доминирует регулярная волна Шолте, локализованная на границы раздела вода – морское дно. В ближней зоне источника возрастает роль обобщенной волны Шолте, локализованной на горизонте источника, а звуковое поле формируется парой волн Шолте, регулярной и обобщенной. The results of experimental studies of the sound field recorded by combined receivers forming a vertically oriented two-element antenna are analyzed. The sound field was formed by discrete components of the vane-blade scale of the noise signal of the science ship «Yuri Molokov» in the infrasonic frequency range of 2–20 Hz, as well as by a towed low-frequency emitter of a polyharmonic signal in the frequency range 30–60 Hz. The depth of the sea and the operating frequency range of 2–20 Hz excluded the possibility of exciting normal waves of the discrete spectrum in the model Pekeris waveguide in this frequency range. Based on the results of spectral analysis of the noise signal, an estimate of the potential noise immunity of the combined receiver was obtained using a full set of informative parameters characterizing the energy structure of the sound field. Based on the results of the analysis of the vertical structure of the sound field in the infrasonic frequency range, it was concluded that the sound field is formed by inhomogeneous normal Scholte waves, regular and generalized (hybrid). In the far zone of the source, a regular Scholte wave dominates, localized at the water – seabed interface. In the near-field zone of the source, the role of the generalized Scholte wave localized at the source horizon increases, and the sound field is formed by a pair of Scholte waves, regular and generalized.

scholarly journals Experimental studies of vibration fields of a freight train in the far zone

2021 ◽  
Vol 2131 (5) ◽  
pp. 052051
Author(s):  
E Ya Bubnov
Keyword(s):  
Solid Medium ◽  
Experimental Studies ◽  
Wave Structure ◽  
Seismic Signal ◽  
Railway Track ◽  
Railway Transport ◽  
Frequency Range ◽  
Freight Train ◽  
Spring Suspension ◽  
Infrasonic Signal

Abstract The article analyzes the sources of radiation of seismic and acoustic signals of railway transport. To determine the wave structure of the seismic field of freight train in the experiment, a linear antenna was used, located at a distance of 1000 m from the railway track. A fine spectral analysis of the seismic signal reveals the presence of two harmonics in the frequency range 1–6 Hz. One of the dominant in amplitude discrete coincides in frequency with the harmonic of the acoustic signal, which indicates the refraction of the acoustic wave into a solid medium at the location of the seismic sensor. The source of the infrasonic signal at the specified frequency can be the resonant oscillation of the car on the spring suspension elasticity. The second discrete at a frequency of 2.7 Hz remains unchanged during the movement of various trains and is even present in microseismic noise, which indicates the imposition of a layered structure of a solid medium. The propagation velocity of this harmonic of the seismic signal is less than the velocity of sound. The totality of the marked features makes it possible to identify this wave with the surface wave formed by the layer.

scholarly journals COMPACT FLUORESCENT LAMPS AS SOURCES OF ELECTROMAGNETIC FIELDS OF RADIO- FREQUENCY RANGE (EXPERIMENTAL STUDY)

2019 ◽  
pp. 59-62
Author(s):  
V.N. Nikitina ◽  
G.G. Lyashko ◽  
N.I. Kalinina ◽  
E.N. Pankina
Keyword(s):  
Experimental Study ◽  
Radio Frequency ◽  
Electromagnetic Fields ◽  
Electric Fields ◽  
Experimental Studies ◽  
Frequency Range ◽  
Electronic Ballast ◽  
Fluorescent Lamps ◽  
Compact Fluorescent Lamps ◽  
Surrounding Space

The objects of this study are compact fluorescent lamps with an electronic ballast and the hygienic assessment of electromagnetic fields created by compact fluorescent lamps. As part of the work, the selection of samples of compact fluorescent lamps for the experimental study of electromagnetic fields was carried out. The background levels of electric and magnetic fields with a frequency of 50 Hz and high-frequency range were measured. Experimental studies of the spectrum and intensity of electromagnetic fields created by compact fluorescent lamps were carried out with different variants of lamp placement (in a cartridge without a light armature, in a local lighting fixture, in general lighting fixtures – chandeliers). The study showed that compact fluorescent lamps equipped with electronic ballast create electromagnetic fields of radio frequency range in the surrounding space. The main frequency of radiation in the examined lamp samples ranged from 32 to 58 kHz. The intensity of electric fields created by compact fluorescent lamps may exceed the permissible level set for consumer goods.

scholarly journals The results of experimental studies of VLF–ULF electromagnetic emission by rock samples due to mechanical action

2013 ◽  
Vol 1 (6) ◽  
pp. 7821-7842
Author(s):  
A. A. Panfilov
Keyword(s):  
Laboratory Experiments ◽  
Experimental Studies ◽  
Electromagnetic Emission ◽  
Mechanical Action ◽  
Frequency Range ◽  
Impact Action ◽  
Rock Samples ◽  
Electric Component ◽  
Electromagnetic Signals ◽  
The Impact

Abstract. The paper presents the results of laboratory experiments on electromagnetic emission excitation (electric component of electromagnetic field) by rock samples due to different forms of mechanical stress applications. It was shown that samples generate electric impulses with different spectra when the impact action, gradual loading or dynamic friction is applied. It was ascertained that level and spectral compositions of signals, generated by rock samples, change with increasing quantity of hits. It was found that strong electromagnetic signals, generated while rock samples were fracturing, were accompanied by repetitive weak, but perceptible variations of the electric field intensity in short frequency range.

scholarly journals A Prototype Model Design of Wide Band Standard Reference Rod-Dipole antenna for 3-Axis EMC Measurement with hybrid Balun for 0.9 to 3.2GHz

2018 ◽  
Vol 7 (1) ◽  
pp. 73-78
Author(s):  
S. Patil ◽  
P. Petkov ◽  
B. Bonev
Keyword(s):  
Return Loss ◽  
Low Cost ◽  
Wide Band ◽  
Dipole Antenna ◽  
Prototype Model ◽  
Electrical Characteristics ◽  
Frequency Range ◽  
Field Site ◽  
Radiation Emission ◽  
Efficient Construction

Every electronics equipment must deal with EMC test. The testing laboratory of electronics equipment for radiation emission must have accurate calibrated antennas. The field strength of total radiated radio frequency is average of all incident signals at given point, this incident spinals originates from various directions. In order to measure three components of all electric field vectors, a tripole antenna is most beneficial over conventional antenna because of it responds to signal coming from multi directions. This paper presents novel three axis wide band calculable rod-dipole antenna with hybrid balun for the range of 900MHz to 3.2GHz frequencies, the proposed antenna is small in size and good electrical characteristics, the Important parameters measured and verified with designed values. Return loss S11 more than -10dB within the frequency range 900MHz to 3.2GHz. The result of this articles are evident that, efficient construction of antenna with low cost, light weight module applicable for EMC pre-compliance test at open field site.

scholarly journals The use of membrane technologies in boiler houses of heat and power enterprises

2019 ◽  
Vol 110 ◽  
pp. 02056
Author(s):  
Elena Kuvardina ◽  
Natalia Semicheva ◽  
Nikolay Kuvardin ◽  
Valery Tolmacheva ◽  
Vasily Amelin
Keyword(s):  
Concentration Polarization ◽  
Membrane Surface ◽  
Experimental Studies ◽  
Low Frequency ◽  
Frequency Range ◽  
Working Process ◽  
Water Stream ◽  
Vibration Effect ◽  
Slowing Down ◽  
Membrane Technologies

The article is about the use of membrane technologies in water treatment cycle for boiler houses which use water of superficial reservoirs for operation. Working process of a flat membrane element is described in the article. Movement scheme of purified water streams is introduced. The layer of undesirable deposits which are slowing down membrane operation is formed on membrane surface during its operation. This formed layer is a result of the arising concentration polarization. Impact of low-frequency fluctuations on saturation water stream is offered to decrease concentration polarization which leads to decline in production of membrane devices. Fluctuations were brought in a stream by means of the vibrator. Steady standing waves are in the membrane device as a result of vibration effect. These waves reduce the formation of undesirable deposits layer on a membrane surface. Results received by mathematical modeling and confirmed by experimental studies state that process productivity of ultrafiltration increased by 30% in frequency range of 60-70 Hz. Frequency range is in standing wave.

Impact of Proton Irradiation on Power 4H-SiC MOSFETs

2020 ◽  
Vol 1004 ◽  
pp. 1074-1080
Author(s):  
Alexander A. Lebedev ◽  
Vitalii V. Kozlovski ◽  
Leonid Fursin ◽  
Anatoly M. Strel'chuk ◽  
Mikhail E. Levinshtein ◽  
...  
Keyword(s):  
Proton Irradiation ◽  
Removal Rate ◽  
Low Frequency ◽  
Frequency Noise ◽  
Electrical Characteristics ◽  
Low Frequency Noise ◽  
Frequency Range ◽  
Maximum Value ◽  
Noise Spectroscopy ◽  
Noise Density

Impact of 15 MeV proton irradiation on electrical characteristics and low frequency noise has been studied in high-power vertical 4H-SiC MOSFETs of 1.2 kV-class at doses 1012 £ F £ 1014 cm-2. The maximum value of the field-effect mobility µFЕ depends weakly on F up to F = 2×1013 cm-2. At F = 4×1013 cm-2, the character of the µFЕ(Vg) dependence changes radically. The maximum µFЕ decreases approximately threefold. The dose Fcr corresponding to the complete degradation of the device is about 1014 cm-2. It can be estimated as Fcr» he/n0, where he is the electron removal rate and n0 is the initial electron concentration in the drift layer. In the entire frequency range of analysis f, gate voltages, and drain-source biases, the frequency dependence of the current spectral noise density SI(f) follows the law SI ~ 1/f. From the data of noise spectroscopy, the density of traps in the gate oxide Ntv has been estimated. In non-irradiated structures, Ntv » 5.4×1018 cm-3eV-1. At Ф = 6×1013 cm-2, the Ntv value increases to Ntv » 7.2×1019cm-3eV-1. The non-monotonic behavior of the output current Id and the level of low frequency noise on dose F has been demonstrated.

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