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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Model terminálu VSAT / VSAT Terminal Model

Kudlička, Miroslav January 2010 (has links)
This work deals with the description of the communication using the VSAT satellite network. A used network topology, frequency bands, satellite orbits and also an access technology are defined. The next part is focused on the VSAT terminal, where the block diagram is shown. A model of the indoor unit IDU is designed in the system background of Ansoft Designer. Individual parts of the system model are analyzed in terms of input variables. The results of the simulation are shown. The curves of BER before Viterbi decoding and after Viterbi decoding are shown too.
2

Estudo da interfer?ncia de uma metasuperf?cie no desempenho das antenas de microfita

Santos, Rafael Celestino dos 16 December 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-20T19:50:21Z No. of bitstreams: 1 RafaelCelestinoDosSantos_DISSERT.pdf: 2928154 bytes, checksum: ed85070c1f646df9265898c17421fbdd (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-22T19:46:13Z (GMT) No. of bitstreams: 1 RafaelCelestinoDosSantos_DISSERT.pdf: 2928154 bytes, checksum: ed85070c1f646df9265898c17421fbdd (MD5) / Made available in DSpace on 2017-03-22T19:46:13Z (GMT). No. of bitstreams: 1 RafaelCelestinoDosSantos_DISSERT.pdf: 2928154 bytes, checksum: ed85070c1f646df9265898c17421fbdd (MD5) Previous issue date: 2016-12-16 / Este trabalho tem por objetivo apresentar a influ?ncia de uma metasuperf?cie, um tipo especial dos metamateriais, no desempenho das antenas de microfitas. As metasuperf?cies s?o materiais artificiais que n?o s?o encontrados em sua forma convencional na natureza e apresentam caracter?sticas eletromagn?ticas n?o convencionais, como o ?ndice de refra??o e os coeficientes de permissividade el?trica e permeabilidade magn?tica negativos o que provocam efeitos eletromagn?ticos atrativos para diversas aplica??es, como por exemplo: melhorar a performance de uma antena de microfita como ser? mostrado nesse trabalho. Iniciaremos o trabalho mostrando um breve hist?rico, defini??es e propriedades eletromagn?ticas das antenas, antenas de microfita, metamateriais e das metasuperf?cies. Em seguida, iremos projetar e confeccionar uma antena de microfita com e sem a utiliza??o de uma metasuperf?cie onde simularemos atrav?s do software HFSS Ansoft Designer e testaremos em laborat?rio atrav?s do equipamento E5071C ENA Network Analyzer. Por fim, realizaremos uma an?lise comparativa, mostrando o quanto a metasuperf?cie melhora a performance de uma antena de microfita atrav?s de uma an?lise dos diversos par?metros da antena, como: perda de retorno, ganho de pot?ncia, diretividade e imped?ncia de entrada. / This paper aims to present the influence of a metasurface, a special type of metamaterials, in the performace of microstrip antennas. The metasurface are artificial materials that are not found in a conventional manner in nature and do not have conventional electromagnetic characteristics such as refractive index and coefficient of permittivity and negative magnetic permeability which causes attractive electromagnetic effects for various applications, such as: improving the performance of a microstrip antenna as will be shown in this work. We started the work showing a brief history, definitions and electromagnetic properties of the antennas, microstrip antennas, metamaterials and metasuperf?cies. Next, we will design and manufacture a microstrip antenna with and without the use of a metasurface where we will simulate through HFSS Ansoft Designer software and test in the laboratory with the E5071C ENA Network Analyzer. Finally, we will perform a comparative analysis, showing how the metasurface improves the performance of a microstrip antenna by analysis of the various parameters antenna, such as: return loss, power gain, directivity and input impedance.
3

Vstupní část přijímače pro pásmo L / L-band receiver front-end

Kolář, Jan January 2012 (has links)
This Master's Thesis deals with a design of L-band receiver front-end. In the concrete the receiver is designed for receiving signals of frequency band 1,3 GHz. All particular blocks from low noise amplifier to intermediate frequency amplifier and frequency doubler in LO input are described, designed and simulated in program Ansoft. The part of this Master's Thesis is aimed to construct a working front-end receiver and to measure its basic parameters.
4

Planární struktury pro vysoké kmitočty / Planar Structures for High Frequency Band

Pulec, Jiří January 2016 (has links)
The present paper deals with the problematics of the design and technology of planar microelectronic structures for the hign frequency band. These structures were realised on the Department of Microelectronics and their properties were measured on the Department of Radioelectronics. The part of this work is also simulation of some microelectronic structures, where for these simulations the design and simulation tool Ansoft Designer and the FEM tool ANSYS was used. The attention is paid to the discrete devices (coils and capacitors) as well as to the more complex structures (frequency filters). The paper yields the new findings in the field of the design and technology of the discrete components as well as of the more complex systems, these findings can be used as the basis for another research of practical applications.
5

Řešení rozložení magnetického pole ve stejnosměrném stroji / Solution magnetic field distribution in DC machine

Hájek, Jan January 2012 (has links)
This thesis deals with distribution of magnetic fields in the DC machine. Part of this thesis is the introduction of DC machines, principles of operation and distribution of DC machines. There is also discussed electrically commutated motors. The thesis demonstrates the types of permanent magnets and their properties. Then there is an analysis of the magnetic field electrically commutated motor Atas Nachod in the Ansoft Maxwell. Using Ansoft Simplorer, switching is carried out of the engine. Another part of this work is the analysisthe magnetic field electrically commutated motor Atas Nachod for three types of slot of the stator of the engine. Here it is seen what impact the change has slot on the distribution of magnetic field in the EC motor. Finally, training is carried out measurements of electrically commutated motor BOYANG BY92BL48-4000-2200.
6

Planární anténní řada pro příjem signálu digitální televize / Planar antenna array for receiving the digital tv signal

Havelka, Michal January 2011 (has links)
The master’s thesis deals in first part with the design of a single antenna element of an antenna array for receiving the digital TV. The resonant frequency of the antenna is 4.7 GHz, the antenna operates in the frequency band 4.4 to 5.0 GHz. Properties of the antenna are verified in programs CST Microwave Studio and Ansoft Designer. The final antenna element is experimentally produced. The second part is devoted to microstrip divider, 2x2 elements antenna array and 4x4 elements antenna array. The antenna array 4x4 elements was produced and its properties were measured.
7

Aktivní anténa se zdvojovačem kmitočtu / Frequency doubling active antenna

Tomíček, Martin January 2011 (has links)
This thesis deals with the analysis of a planar antenna operating at two frequencies with use frequency doubling. The design and simulation of the antenna in ANSOFT Designer is described. The antenna is designed for two operating frequencies 900 MHz and 1.8 GHz. The antenna is required to operate TM10 mode and TM01 modes.
8

Subharmonické směšovače pro mikrovlnná pásma / Subharmonic Mixers for Microwave Bands

Kintr, Jindřich January 2016 (has links)
The task of this master’s thesis is design and implementation subharmonic mixer for the microwave band. Subharmonic mixer is based on the principle of antiparallel diode. In the first two parts are theoretically described mixers (subharmonic mixer) and topology suitable for implementation. Another work describes the design subharmonic mixer. The proposal is implemented in the program Ansoft designer. DPS is created in Eagle or in Ansoft Designer. The mixer is designed and implemented first on the lower frequency and consequently at higher frequencies (24,048 GHz and 47,088 GHz). Work also includes the measurement results of the mixer.
9

Subharmonické směšovače pro mikrovlnná pásma / Subharmonic Mixers for Microwave Bands

Kintr, Jindřich January 2016 (has links)
The task of this master’s thesis is design and implementation subharmonic mixer for the microwave band. Subharmonic mixer is based on the principle of antiparallel diode. In the first two parts are theoretically described mixers (subharmonic mixer) and topology suitable for implementation. Another work describes the design subharmonic mixer. The proposal is implemented in the program Ansoft designer. DPS is created in Eagle or in Ansoft Designer. The mixers are designed and implemented first on the lower frequency and consequently at higher frequencies (24,048 GHz and 47,088 GHz). Work also includes the measurement results of the mixers.
10

Anténní předzesilovač pro měření EMI / Antenna preamplifier for EMI measurements

Sedlák, Milan January 2018 (has links)
The master thesis deals with the design of a low noise preamplifier operating in the frequency range from 30 MHz to 1 GHz, usable for measuring and testing of electromagnetic interference in the electromagnetic compatibility test rooms. The introductory, theoretical, part is focused on the analysis and description of the necessary properties of the low noise preamplifier required for the subsequent design. The practical part deals with the selection of suitable components, simulation, design and subsequent realization of low noise preamplifier. At the end of the thesis the design and the final verification measurements are described and discussed.

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