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Wyszukujesz frazę "diode" wg kryterium: Temat


Tytuł:
Modification of mirowave frequency detector characteristic with the use of phase shifter
Autorzy:
Rećko, C.
Stec, B.
Powiązania:
https://bibliotekanauki.pl/articles/221689.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
frequency detector
phase detector
diode ring
Opis:
Microwave frequency detectors enable immediate determination of an unknown microwave signal frequency. Measurement is possible if the output characteristic of a frequency detector is unequivocal in a selected band of operation. The paper presents a method for obtaining unequivocal output characteristics for a given band of frequency detector operation.
Źródło:
Metrology and Measurement Systems; 2018, 25, 4; 769-777
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Influence of the Laser Beam Fluence on Change in Microstructure, Microhardness and Phase Composition of Feb-Fe2B Surface Layers Produced on Vanadis-6 Steel
Autorzy:
Bartkowska, A.
Jurči, P.
Hudáková, M.
Bartkowski, D.
Kusý, M.
Przestacki, D.
Powiązania:
https://bibliotekanauki.pl/articles/352487.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
diode laser
boronizing
laser modification
microstructure
Vanadis steel
Opis:
The paper presents the study results of laser modification of Vanadis-6 steel after diffusion boronized. The influence of laser beam fluence on selected properties was investigated. Diffusion boronizing lead to formation the FeB and Fe2B iron borides. After laser modification the layers were consisted of: remelted zone, heat affected zone and substrate. It was found that increase of laser beam fluence have influence on increase in dimensions of laser tracks. In the thicker remelting zone, the primary dendrites and boron eutectics were detected. In the thinner remelting zone the primary carbo-borides and eutectics were observed. In obtained layers the FeB, Fe2B, Fe3B0.7C0.3 and Cr2B phases were detected. Laser remelting process caused obtained the mild microhardness gradient from the surface to the substrate. In the remelted zone was in the range from 1800 HV0.1 to 1000 HV0.1. It was found that the laser beam fluence equal to 12.7 J/mm2 was most favorable. Using this value, microhardness was relatively high and homogeneous.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 791-800
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laser diode distance measuring interferometer - metrological properties
Autorzy:
Dobosz, M.
Powiązania:
https://bibliotekanauki.pl/articles/221882.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
diode laser
wavelength stabilization
interferometer
interferometer distance measurement
Opis:
A novel laser diode based length measuring interferometer for scientific and industrial metrology is presented. Wavelength the stabilization system applied in the interferometer is based on the optical wedge interferometer. Main components of the interferometer such as: laser diode stabilization assembly, photodetection system, measuring software, air parameters compensator and base optical assemblies are described. Metrological properties of the device such as resolution, measuring range, repeatability and accuracy are characterized.
Źródło:
Metrology and Measurement Systems; 2012, 19, 3; 553-564
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Band Notch Characteristics Reconfigurable UWB Leaf Shape Monopole Antenna
Autorzy:
Muthusamy, Pachiyaannan
Nallapaneni, Srikanta
Perumalla, Krishna Chaitanya
Punna, Bharghava
Powiązania:
https://bibliotekanauki.pl/articles/2055232.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
band notch
PIN diode
leaf shape monopole antenna
reconfigurable
UWB
Opis:
In this paper a band notch characteristics reconfigurable UWB leaf shape monopole antenna is reported. The proposed antenna size is 42×32×1.6 mm³ and simulated S11-10dB impedance bandwidth is from 2.1 to 13.0 GHz. The notch bands are embodied into the designed antenna to suppress Bluetooth and WiFi bands from 2.3-2.7 GHz and 4.6-5.3 GHz. The PIN Diode is loaded to slot on the DGS to achieve notch bands. It has 4.48dB and 1.7dB gain achieved when diode ON and OFF condition. Further, it encompasses a bio-inspired leaf shape patch having high feasibility for deployment in secret and military purposes.
Źródło:
International Journal of Electronics and Telecommunications; 2022, 68, 2; 223--228
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study of Susceptibility and Evaluation of Causes of Cracks Formation in Braze-Weld Filler Metal in Lap Joints Aluminum – Carbon Steel Made with Use of CMT Method and High Power Diode Laser
Autorzy:
Adamiak, M.
Wyględacz, B.
Czupryński, A.
Górka, J.
Powiązania:
https://bibliotekanauki.pl/articles/958197.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
braze-welding
intermetallic compound phase
high power diode laser
brazing
Opis:
In this article results of studies on cracks formation susceptibility in braze-welded joints of thin aluminum sheets and double-sided zinc galvanized steel sheets for car body parts made by laser brazing with high power diode laser ROFIN DL 020 and CMT MIG-brazing, with filler material in form of powder and wire accordingly, were presented. Optimal welding parameters were determined by visual acceptance criteria. On joints made with optimal parameters further examinations were carried. Results of macro- and microscopic metallographic examinations, structural roentgenography, EDS microanalysis and hardness tests were presented. Causes of brittle intermetallic Fe-Al phases formation in Al-matrix filler metal in dissimilar aluminum – zinc plated carbon steel joints were pointed.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 4; 2113-2123
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Frequency Reconfigurable Split Ring Antenna for LTE And WiMAX Applications
Autorzy:
Madhav, B. T. P.
Nadh, B.
Anilkumar, T.
Pardhasaradhi, P.
Rao, M. C.
Lakshman, P.
Powiązania:
https://bibliotekanauki.pl/articles/226800.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PIN diode
WiMAX
LTE 2500
split ring antenna
BAR64-02V
Opis:
This paper presents frequency reconfigurable dual band antenna for WiMAX and LTE 2500 band applications using four PIN diode switches. The antenna is compact in size with dimensions of 30 x 30 x 0.8 mm3 and designed on FR-4 dielectric substrate with a partial ground plane. The fabricated antenna operates in the frequency range of LTE and WiMAX (2.5-2.69 GHz and 3.4-3.6 GHz) respectively. The frequencies can be controlled by using PIN diodes and antenna attained the gain ranging of 3.34-4.46 dBi. This designed antenna resonating at 2.52 and 3.49 GHz when the PIN diodes are in ON state and resonating at 2.68 and 3.58 GHz when PIN diodes are in OFF state. The proposed antenna has bidirectional radiation at upper frequency bands and unidirectional at lower frequency bands. The proposed split ring structured antenna has the radiation efficiency of 94.12% at 2.52 GHz and 90.34% at 3.49 GHz in ON state. Antenna providing good agreement between the measured (Antenna measurement setup with VNA) and simulated results (Ansys-HFSS).
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 2; 255-260
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diode Laser Surface Alloying of Armor Steel with Tungsten Carbide
Autorzy:
Janicki, D.
Górka, J.
Kwaśny, W.
Gołombek, K.
Kondracki, M.
Żuk, M.
Powiązania:
https://bibliotekanauki.pl/articles/351086.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
laser surface alloying
diode laser
armor steel
metal matrix composite
tungsten carbide
Opis:
Metal matrix composite (MMC) surface layers reinforced by WC were fabricated on armor steel ARMOX 500T plates via a laser surface alloying process. The microstructure of the layers was assessed by scanning electron microscopy and X-ray diffraction. The surface layers having the WC fraction up to 71 vol% and an average hardness of 1300 HV were produced. The thickness of these layers was up to 650 μm. The addition of a titanium powder in the molten pool increased the wettability of WC particles by the liquid metal in the molten pool increasing the WC fraction. Additionally, the presence of titanium resulted in the precipitation of the (Ti,W)C phase, which significantly reduced the fraction of W-rich complex carbides and improved a structural integrity of the layers.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 2A; 473-481
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Titanium Metal Matrix Composite Surface Layers Produced During Laser Gas Nitriding of Ti6Al4V Alloy by Different Types of Lasers
Autorzy:
Lisiecki, A.
Powiązania:
https://bibliotekanauki.pl/articles/351670.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
titanium alloys
laser gas nitriding
composite surface layer
disk laser
diode laser
Opis:
The article presents the results of a comparative study of the nitriding process of titanium alloy substrate using two lasers with different characteristics of laser beams. One of the applied lasers was a high power diode laser emitting at a dominant wavelength of 808 nm, with a rectangular laser beam spot, and multimode energy distribution across the spot. The second laser was a solid state Yb:YAG disk laser emitting at a wavelength of 1.03 μm, with a circular beam spot, characterized by near Gaussian energy distribution across the spot. In a case of both lasers single stringer beads with a similar width and at similar energy input were produced. As a result of melting of the substrate with a laser beam in a pure gaseous nitrogen atmosphere composite surface layers with in situ precipitated titanium nitrides embedded in the metallic matrix of titanium alloy were produced, in both cases. However, the surface topography and structure is different for the surface layers produce by different lasers at the same processing parameters and width of laser beams.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 4; 1777-1784
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructural Evolution During Laser Surface Alloying of Ductile Cast Iron with Titanium
Autorzy:
Janicki, D.
Powiązania:
https://bibliotekanauki.pl/articles/351680.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
in-situ composites
TiC
laser surface alloying
diode laser
ductile cast iron
Opis:
Diode laser surface alloying process was used to the in-situ synthesis of TiC-reinforced composite surface layers on the ductile cast iron substrate. The obtained composite surface layers were investigated using optical and scanning electron microscopy, and XRD diffraction. It was found that the morphology and fraction of TiC phase is directly dependent upon both the concentration of titanium in the molten pool and also the solidification rate. With increasing titanium content, the fraction of TiC increases, whereas the fraction of cementite decreases. The TiC phase promotes a heterogeneous nucleation of primary austenite grains, what reduces a tendency of cracking in the alloyed layers.
Źródło:
Archives of Metallurgy and Materials; 2017, 62, 4; 2425-2431
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the Averaged Model of the Diode-transistor Switch for Modelling Characteristics of a Boost Converter with an IGBT
Autorzy:
Górecki, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/226814.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
DC-DC converter
IGBT
boost converter
averaged model
diode-transistor switch
modelling
SPICE
Opis:
DC-DC converters are popular switch-mode electronic circuits used in power supply systems of many electronic devices. Designing such converters requires reliable computation methods and models of components contained in these converters, allowing for accurate and fast computations of their characteristics. In the paper, a new averaged model of a diode-transistor switch containing an IGBT is proposed. The form of the developed model is presented. Its accuracy is verified by comparing the computed characteristics of the boost converter with the characteristics computed in SPICE using a transient analysis and literature models of a diode and an IGBT. The obtained results of computations proved the usefulness of the proposed model.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 3; 555-560
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
GaInNAs quantum-well vertical-cavity surface-emitting lasers emitting at 2.33 μm
Autorzy:
Piskorski, Ł.
Sarzała, R. P.
Powiązania:
https://bibliotekanauki.pl/articles/199958.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
simulation of a diode-laser operation
QW VCSELs
mid-infrared radiation
dilute nitrides
Opis:
In the present paper, the comprehensive fully self-consistent optical-electrical-thermal-recombination model is used to determine the optimal structure of the possible GaInNAs quantum-well (QW) tunnel-junction (TJ) vertical-cavity surface-emitting lasers (VCSELs) with single-fundamental-mode operation at 2.33 μm wavelength suited for carbon monoxide sensing applications. From among various considered structures, the diode laser with 4-μm TJ and two 6-nm Ga0.15In0.85N0.015As0.985/Ga0.327In0.673As0.71P0.29 QWs has the lowest threshold current and seems to be optimal for the above applications. Higher threshold currents are obtained for Ga0.15In0.85N0.015As0.985/Al0.138 -Ga0.332In0.530As QW structures but the latter can be grown in reactors without P source which are used for fabrication of GaAs-based devices. Both the modelled VCSELs offer a very promising room temperature continuous wave performance and may represent an alternative choice to GaSb-based lasers.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 3; 737-744
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three-phase diode rectifier with current modulator in DC circuit based on multi-channel converter
Autorzy:
Krystkowiak, M.
Gwóźdź, M.
Powiązania:
https://bibliotekanauki.pl/articles/141635.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
control methods of electrical systems
diode rectifier
generalized sampling
expansion
multi-channel converter
PWM
Opis:
In the paper the 3-phase power diode rectifier system with quasi-sinusoidal input (power grid) current is presented. In order to benefit from it, the current modulation in the DC circuit of a rectifier is used. The essential part of the current modulator is the wide-band power electronics controlled current source based on a multi-channel converter. The control algorithm of the current modulator respects impact of aliasing phenomena at system stability by using the method proposed by the authors. The paper includes the rectifier system description and rules of operation of the current modulator. Also, some results of research on both the rectifier simulation model and the laboratory prototype of a current modulator are presented.
Źródło:
Archives of Electrical Engineering; 2017, 66, 3; 533-545
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Edge termination design for 1.7 kV silicon carbide p-i-n diodes
Autorzy:
Taube, A.
Sochacki, M.
Powiązania:
https://bibliotekanauki.pl/articles/199922.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
edge termination
silicon carbide
4H-SiC
p-i-n diode
breakdown voltage
JTE
Opis:
In this work, in order to obtain breakdown voltage values of the 4H-SiC p-i-n diodes above 1.7 kV, three designs have been examined: single-zone junction termination extention (JTE), double-zone JTE and a structure with concentric rings outside each of the areas of the double-zone JTE (space-modulated JTE). The influence of geometry and the level of p-type doping in the JTE area as well as the charge as the interface between the p-type JTE area and the passivation layer on the diode breakdown voltage was studied. The effect of statistical dispersion of drift layer parameters (thickness, doping level) on diodes breakdown voltage with various JTE structures was investigated as well. The obtained results showed that the breakdown volatge values for a diode with single zone JTE are very sensitive both to the dose of JTE area and charge accumulated at the JTE/dielectric interface. The use of a double zone or space-modulated JTE structures allows for obtaining breakdown voltage above 1.7 kV for a much wider range of doping parameters and with better tolerance to positive charge at the JTE/dielectric interface, as well as better tolerance to statistical dispersion of active layer parameters compared to a single zone JTE structure.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2020, 68, 2; 367-375
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of a micro-channel heat sink for cooling of high-power laser diode arrays
Autorzy:
Furmański, P.
Thualfaqir, K.
Łapka, P.
Powiązania:
https://bibliotekanauki.pl/articles/240825.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
micro heat sink
laser diode arrays cooling
numerical simulation
chłodzenie
laser
dioda
radiator
modelowanie numeryczne
Opis:
Micro-channel heat sinks are used in a wide variety of applications, including microelectronic devices, computers and high-energy-laser mirrors. Due to the high power density that is encountered in these devices (the density of delivered electrical power up to a few kW/cm2 ) they require efficient cooling as their temperatures must generally not exceed 100 °C. In the paper a new design for micro-channel heat sink (MCHS) to be used for cooling laser diode arrays (LDA) is considered. It is made from copper and consisting of 37 micro-channels with length of 9.78 mm, width of 190 µm and depth of 180 µm with the deionized water as a cooling medium. Mathematical and numerical models of the proposed design of the heat sink were developed. A series of thermofluid numerical simulations were performed for various volumetric flow rates of the cooling medium, its inlet temperature and different thermal power released in the laser diode. The results show that the LDA temperature could be decreased from 14 to 17% in comparison with earlier proposed design of the heat sink with the further drop in temperature obtained by applying indium instead of gallium arsenide as the soldering material between the LDA and MCHS interface. Moreover, it was found that the maximum temperature, and therefore the thermal resistance of the considered heat sink, could be decreased by increasing the coolant flow rate.
Źródło:
Archives of Thermodynamics; 2018, 39, 3; 15-27
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generation of two identical ns laser pulses at single μs spacing by switching output mirror transmission
Autorzy:
Skórczakowski, Marek
Żendzian, Waldemar
Jankiewicz, Zdzisław
Powiązania:
https://bibliotekanauki.pl/articles/220917.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
double pulse Q-switched laser
pulsed holographic interferometry
transmission losses switching
diode pumped Q-switched laser
Opis:
Generation of two identical ns laser pulses spaced by a single μs time interval by means of sequential switching of the output mirror transmittance in a diode-pumped Nd:YAG laser is reported, to our knowledge, for the first time. The theoretical study of the process of transmission losses switching is developed. This analysis confirms the possibility of generation of two identical Q-switched laser pulses with 100% efficiency with respect to the referenced single pulse energy. The detailed characterization of the laser in free-running, single and double Q-switching regimes is presented. The laser can be applied in different branches of metrology as PIV, LIBS or holographic interferometry.
Źródło:
Metrology and Measurement Systems; 2020, 27, 3; 513-530
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł

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