Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "arrays" wg kryterium: Temat


Tytuł:
Phased array antennas in MIMO receiver
Autorzy:
Kozłowski, S.
Yashchyshyn, Y.
Modelski, J.
Powiązania:
https://bibliotekanauki.pl/articles/307622.pdf
Data publikacji:
2007
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
MIMO system
phased arrays antennas
Opis:
In this paper, a computer simulation of a MIMO system comprising phased array antennas (PAA) in all receiving branches is presented. In order to examine the system performance under relatively realistic conditions, a ray-tracing simulator was applied to generate a baseband channel impulse response matrix H. A bit error rate (BER) of two systems utilizing different detection methods: V-BLAST and simple matrix inversion was examined in order to determine phased array antennas applicability. Results of an attempt to determine relationship between BER and properties of particular matrix H realization are also provided.
Źródło:
Journal of Telecommunications and Information Technology; 2007, 1; 26-29
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monoimpulsowa metoda automatycznego śledzenia trajektorii pocisku
Monopulse method of missile trajectory automatic tracking
Autorzy:
Bodjański, M.
Powiązania:
https://bibliotekanauki.pl/articles/235255.pdf
Data publikacji:
2005
Wydawca:
Wojskowy Instytut Techniczny Uzbrojenia
Tematy:
układy antenowe
trajektoria pocisku
antennas arrays
Opis:
W artykule przedstawiono monoimpulsową metodę sterowania układami nadążnymi zespołu antenowego radaru śledzącego trajektorię pocisku. Zestawiono wyniki symulacji algorytmów pozycjonowania z rzeczywistą trajektorią pocisku kalibru 105 mm, zarejestrowaną przez stację balistyczną DR6700.
A monopulse method used to control antenna drive systems in the missile trajectory tracking radar is presented in the paper. Results of simulation of positioning algorithms are compared with the real 105 mm round trajectory recorded by the ballistic station DR 6700.
Źródło:
Problemy Techniki Uzbrojenia; 2005, R. 34, z. 96; 139-145
1230-3801
Pojawia się w:
Problemy Techniki Uzbrojenia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Side lobes reducing by variation of array apperture edge shape
Autorzy:
Gorobets, N.N.
Gorobets, Yu.N.
Kiyko, V.I.
Powiązania:
https://bibliotekanauki.pl/articles/308797.pdf
Data publikacji:
2000
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
phone antenna arrays
side lobes level reducing
Opis:
A possibility of side lobes level reducing in plane antenna array by creation of aperture comb edge in arrays with rectangular and circular aperture shape together with usage of different types of reducing to the array edges amplitude distributions is investigated by computer analysis. It is shown that usage of the comb structure in combination with the reducing amplitude distribution enables one to reach the side lobes level reducing in the array to -27 ÷ -29 dB.
Źródło:
Journal of Telecommunications and Information Technology; 2000, 1-2; 85-89
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of polarized signals on the performance of adaptive antenna arrays
Autorzy:
Al Ka'bi, Amin H.
Powiązania:
https://bibliotekanauki.pl/articles/949909.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
adaptive arrays
antennas
electromagnetics
mutual coupling
polarization
Opis:
The polarized electromagnetic waves have significant impact on the performance of adaptive antenna arrays. In this paper we investigate the effect of polarized desired and undesired signals on the performance of electronically steered beam adaptive antenna arrays. To achieve this goal, we built an analytical signal model for the adaptive array, in order to analyze, and compare the effect of polarized signals on the output SINRs (signal to interference plus noise ratios) of single-dipole, and cross-dipole adaptive antenna arrays. Based on a proof-of-concept experiment, and on MATLAB simulation results, it will be shown that cross-dipole adaptive antenna arrays exhibit better performance in comparison with single-dipole adaptive antenna arrays in presence of randomly polarized signals. However, single-dipole arrays show better performance under certain operating conditions.
Źródło:
Archives of Electrical Engineering; 2020, 69, 4; 857-872
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of optical dispersion techniques in phased array antenna beam steering
Autorzy:
Muszkowski, M.
Sędek, E.
Powiązania:
https://bibliotekanauki.pl/articles/307765.pdf
Data publikacji:
2005
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
phased arrays antennas
fiber optic
dispersion
laser
Opis:
The paper presents an opto-electronic system for antenna beam control and results of model system measurements.
Źródło:
Journal of Telecommunications and Information Technology; 2005, 2; 50-52
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
How to enhance a room-temperature operation of diode lasers and their arrays
Autorzy:
Sarzała, R. P.
Sokół, A. K.
Kuc, M.
Nakwaski, W.
Powiązania:
https://bibliotekanauki.pl/articles/174004.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
diode laser
thermal management
thermal crosstalk
semiconductor arrays
Opis:
A key problem to be solved during designing productive diode lasers and their lasing arrays is their proper thermal management enabling efficient high-power operation. Strictly speaking, the above demand leads to optimization of their structures to enhance lasing performance for high operation currents. It is well-known that deterioration of laser performance is mostly induced by excessive temperature increases within their volumes. In diode-laser arrays, additionally thermal crosstalk between array emitters should be taken into account. In the present paper, physics of heat-flux generation within the laser-diode volume and its extraction from it is analysed and described with the aid of our self-consistent simulation procedure. Then their thermal optimization is discussed including a proper design of a heat-flux generation within the laser volume, enhancement of its transport towards a laser heat-sink and, additionally in laser arrays, reduction of a thermal crosstalk between individual array emitters. The analysis is carried out using modern nitride edge-emitting ridge-waveguide lasers and their one-dimensional arrays as well as arsenide semiconductor disk lasers as typical examples of modern diode-laser designs. Physical processes responsible for heat-flux generation within these devices and heat-flux extraction from their volumes are analysed and an impact of some construction details on these processes is explained.
Źródło:
Optica Applicata; 2016, 46, 2; 213-226
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Introduction to Virtual Phased Arrays for Beamforming Applications
Autorzy:
Comesaña, D. F.
Holland, K. R.
Escribano, D. G.
de Bree, H. E.
Powiązania:
https://bibliotekanauki.pl/articles/176345.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
beamforming
source localization
virtual phased arrays
measurement techniques
Opis:
Sound localization problems are usually tackled by the acquisition of data from phased microphone arrays and the application of acoustic holography or beamforming algorithms. However, the number of sensors required to achieve reliable results is often prohibitive, particularly if the frequency range of interest is wide. It is shown that the number of sensors required can be reduced dramatically providing the sound field is time stationary. The use of scanning techniques such as “Scan & Paint” allows for the gathering of data across a sound field in a fast and efficient way, using a single sensor and webcam only. It is also possible to characterize the relative phase field by including an additional static microphone during the acquisition process. This paper presents the theoretical and experimental basis of the proposed method to localise sound sources using only one fixed microphone and one moving acoustic sensor. The accuracy and resolution of the method have been proven to be comparable to large microphone arrays, thus constituting the so called “virtual phased arrays”.
Źródło:
Archives of Acoustics; 2014, 39, 1; 81-88
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Full-wave Analysis of Periodic Baffle System in Beamforming Applications
Autorzy:
Tasinkevych, Y.
Danicki, E.
Powiązania:
https://bibliotekanauki.pl/articles/177861.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sound field calculation
linear phased arrays
BIS expansion
far-field radiation pattern
beam-steering
transducer arrays
composite transducers
scattering
generation
fields
Opis:
Mixed boundary-value problem for periodic baffles in acoustic medium is solved with help of the method developed earlier in electrostatics. The nice feature of the method is that the resulting matrices are relatively easy for computations and that the results satisfy exactly the energy conservation law. Illustrative numerical examples present the wave-beam steering (in the far-field) in a baffle system that may be considered as a model of one-dimensional ultrasonic transducer array.
Źródło:
Archives of Acoustics; 2010, 35, 4; 661-675
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial power combiner using a planar active transmitarray of stacked patches
Autorzy:
Tai, F.-C. E.
Białkowski, M. E.
Powiązania:
https://bibliotekanauki.pl/articles/307767.pdf
Data publikacji:
2005
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
active antennas
amplifiers
microstrip antennas
planar arrays
power combiners
Opis:
An X-band spatial power combiner, which uses a planar transmitarray (TXA) of orthogonally polarized stacked microstrip patches integrated with input and output ports of transistor amplifiers is described. In order to obtain an increased operational bandwidth, the unit cell of the combiner with various stacked patch (SP) configurations is investigated. The configuration showing the smallest insertion losses is chosen for developing a TXA. The constructed spatial combiner includes a 4×4 cell TXA placed between two hard horn antennas. Its performance is assessed experimentally in terms of amplification gain and combining efficiency.
Źródło:
Journal of Telecommunications and Information Technology; 2005, 2; 45-49
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesizing Non-Uniformly Excited Antenna Arrays Using Tiled Subarray Blocks
Autorzy:
Mohammed, Jafar Ramadhan
Powiązania:
https://bibliotekanauki.pl/articles/27312954.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
antenna arrays
non-uniform amplitudes
performance optimization
tiled subarray blocks
Opis:
Conventionally, non-uniformly excited antenna arrays are synthesized by independently determining the excitation amplitude and phase of each single element. Such an approach is considered to be the most expensive and complex design method available. In this paper, the tilling technique is harnessed to synthesize non-uniformly excited antenna arrays. To apply this technique, the array elements are first divided into different subarray shapes, such as rectangles or squares known as tiles. The use of rectangular tile blocks instead of a single element architecture greatly simplifies the array design process and reduces array complexity. Next, the problem concerned with synthesizing sub-arrays comprising rectangular tile blocks is formulated and solved by using horizontal and vertical orientations of tiles having different shapes and sizes, and their larger integer expansions. The third approach to tiled design is a mixture of both previous tile architectures. A genetic algorithm is used to design such tiled arrays offering optimum sidelobe levels, beam width, directivity and taper efficiency. Simulation results demonstrated the effectiveness of the proposed tiled arrays.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 4; 25--29
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance investigation and element optimization of 2D array transducer using Bat Algorithm
Autorzy:
Tantawy, Dina Mohamed
Eladawy, Mohamed
Hassan, Mohamed Alimaher
Mubarak, Roaa
Powiązania:
https://bibliotekanauki.pl/articles/140685.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
2D ultrasound arrays
Binary Bat Algorithm
Genetic Algorithm
Optimization
Opis:
One of the least expensive and safest diagnostic modalities routinely used is ultrasound imaging. An attractive development in this field is a two-dimensional (2D) matrix probe with three-dimensional (3D) imaging. The main problems to implement this probe come from a large number of elements they need to use. When the number of elements is reduced the side lobes arising from the transducer change along with the grating lobes that are linked to the periodic disposition of the elements. The grating lobes are reduced by placing the elements without any consideration of the grid. In this study, the Binary Bat Algorithm (BBA) is used to optimize the number of active elements in order to lower the side lobe level. The results are compared to other optimization methods to validate the proposed algorithm.
Źródło:
Archives of Electrical Engineering; 2020, 69, 3; 561-579
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The DDS Synthesizer (for FPGA Platform) for the Purpose of Research and Education
Autorzy:
Szomiński, Szymon
Plichta, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1373686.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
frequency synthesis
digital oscillations
field programmable gate arrays systems
FPGA
Opis:
The paper concerns the construction scheme of Direct Digital Synthesis (DDS) generator based on widely developed Field Programmable Gate Arrays (FPGA) technology. Firstly, the division of all generators is presented regarding the fact whether they generate sinusoidal or non-sinusoidal signals and whether the they have positive or negative feedback. Next chapter concerns how to generate frequency directly and indirectly synthesis and how to integrate these types of sytheses into the hybrid one. According to the blueprint, DDS generator if fully digital, which facilitates the control enabling to change almost at will the oscillation while the system works. Next chapters contain the conclusions and some proposals regarding practical application. DDS synthesizer has been made in accordance to the assumptions of the project, which was confirmed in practice. Control program enables us to fuse some measuring systems together into one, which facilitates simultaneous gathering of the data from several devices. Hence, the overall efficiency rises and the costs of carried out experiments are reduced. In the case of foreigners, it will be supplied by editors.
Źródło:
Schedae Informaticae; 2015, 24; 253-260
0860-0295
2083-8476
Pojawia się w:
Schedae Informaticae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Localization of Sound Sources during Full Scale Fatigue Test of the Vertical Stabilizer with the Acoustic Holography Technique
Autorzy:
Leski, A.
Szmidt, M.
Synaszko, P.
Powiązania:
https://bibliotekanauki.pl/articles/97947.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
acoustic holography
Full Scale Fatigue Test
damage detection
microphone arrays
Opis:
An acoustic holography and its practical applications in engineering began to develop at the end of the 20th century. Currently, this technique is being commonly used to locate sound sources. This paper presents the use of an acoustic camera to locate sound sources during the Full Scale Fatigue Test of the MiG-29 stabilizer. During fatigue tests, the tested structure issues a series of sounds in the form of glitches, creaks or beats. These sounds are typical for a structure subjected to dynamic loading, but they can also be a source of diagnostic information about places of fatigue failures. The paper presents the results of measurements made during the fatigue test. Thanks to the analysis of the measurement results, it was possible to identify areas that are the basic source of sounds.
Źródło:
Fatigue of Aircraft Structures; 2017, 9; 17-25
2081-7738
2300-7591
Pojawia się w:
Fatigue of Aircraft Structures
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adaptive and Evolvable Hardware and Systems: The State of the Art and the Prospectus for Future Development
Autorzy:
Negoita, M. G.
Sekanina, L.
Stoica, A.
Powiązania:
https://bibliotekanauki.pl/articles/385007.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
Evolvable Hardware (EHW)
evolutionary design
reconfigurable hardware
FieldProgrammable Analogue Arrays (FPAA)
Opis:
This paper is an overview on the Evolvable Hardware (EHW) - the exciting and rapidly expanding industrial application area of the Evolutionary Computing (EC), of the Genetic Algorithms especially. The content of the work has the following structure: the first part includes generalities on industrial applications of EC, and the importance of EHW in this frame; the second part presents the outstanding technological support making possible the implementation of system adaptation in hardware. Different kind of programmable circuits arrays are introduced. The third part tackles the most known EC based methods for EHW implementation; the fourth part deals with some concrete elements of the EHW design, including the current limits in evolutionary design of digital circuits. The last part is focused on some concluding remarks with regard to future perspectives of the area. A list of references used in this work was inserted at the end.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2009, 3, 2; 70-75
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generation of Asymmetrical Difference Patterns from Array Antennas
Autorzy:
Satyanarayana, M.
Raju, G. S. N.
Powiązania:
https://bibliotekanauki.pl/articles/226481.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
asymmetric patterns
arrays
array antennas
marine
radars
amplitude distributions
phase distributions
Opis:
It is common to produce sum patterns from array antennas. These patterns are basically symmetric with one main lode in bore sight and symmetric sidelobe structure around the main beam. The antennas associated with the marine radars are required to produce patterns with asymmetric side lobes. Asymmetrical patterns are very useful for marine radars when ships sail in turbulent water where roll and pitch exists.In particular the sidelobes in one side are lower than those of the other side. It is also essential to produce difference patterns with asymmetric structure from the boresight direction. These patterns are required to have null in the bore sight and high difference slope in the same direction. When these patterns are required from marine radars, the side lobes associated with the difference pattern on the either side of the boresight is at the different heights. In the present work, such useful patterns are generated from the newly designed arrays. The amplitude and phase distributions are designed for small and large arrays. The radiation patterns are numerically computed and they are presented in u- domain.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 2; 185-190
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies