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Design of meander RFID antenna
Horák, David ; Šebesta, Jiří (referee) ; Lukeš, Zbyněk (advisor)
This thesis deals with RFID tags. In the first part of the thesis, the general overviews of the present-day RFID systems are presented. This part of the thesis is focused on the passive back-scatter UHF tags and the advantages of their application in supply chain usage. Subsequently, the electromagnetic simulators CST Microwave Studio and IE3D Zeland are described. These simulators were used to design loaded meander antennas. The antennas were designed for different materials and frequency bands of 867 MHz and 2.4 GHz. The designed antennas were made without as well as with the reflector which allows using the antennas in the vicinity of metals. Produced antennas were experimentally tested in the company METRA Blansko Inc, where one of the most significant characteristics of passive RFID tags – the read range was observed.
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Low Altitude FM Radioaltimeter
Pítra, Kamil ; Šebesta, Jiří (referee) ; Józsa, Ladislav (advisor)
The aim of my bachelor thesis is to design a Low altitude FM radioaltimeter based on heterodyne frequency measurement. Radiolocator works in 5,760 GHz frequency band. Its design is based on solving peripheral circuits. There are no RF modules used. Design of each of them is supported by simulations and measurements.
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VGA image generation with microcontroller
Polášek, Jan ; Šebesta, Jiří (referee) ; Fedra, Zbyněk (advisor)
This bachelor’s thesis is concerned with generating image in VGA format using microcontroller. It’s aimed at microcontrollers series AVR from producer Atmel. Project contains VGA interface description, solves its connection to microcontroller’s output ports, further it contains connection diagram of image generation device with microcontroller Atmel ATmega324P, that I constructed during work on this project.. In project are analyzed fundamentals of image generating in microcontroller, synchronization of image using microcontroller’s internal counter, creating of simple graphic images and text and principles of generating colour images. Generation of text is analyzed in details, including source code for microcontroller. The result of this bachelor‘s thesis is functional image generator device.
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Ground Station Antennas for Satellite Communication in VHF and UHF Bands
Červenka, Ivan ; Šebesta, Jiří (referee) ; Vyskočil, Pavel (advisor)
Subject of my bachelor's project is to study Yagi's problems of kross antennas with circle polarization, their designs of simulation and construction. Kross antennas with circle polarization should be designed for frequency band f=145 MHz and f=435 MHz. This project is oriented mainly on components simulation, their influence on final character of antenne, to reach an optimal antennes design and practical tests of simulations.
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Impedance Transformers with Impedance Ratio 1/50 Ohms for Wide Frequency Range
Zachar, Jiří ; Šebesta, Jiří (referee) ; Dřínovský, Jiří (advisor)
One of the aims of this bachelor’s project was to explore possibilities of the design of impedance transformers for a very wide frequency bandwidth (10 Hz – 100 MHz) with the impedance ratio 1/50 . It is not possible to cover this wide frequency band by one transformer, so the design was split into the design of two impedance transformers. The first transformer was realized on the ferrite coil RIK20. The second transformer was realized by with the components T16-1 and TT25-1-kk+ produced by Mini-CircuitsŽ company, and transform impedance directly in a high frequency range. The performance of realized transformers was approved by measuring transformed impedance on their outputs. The frequency band of transformers was determined from these data. Their insertion loss was also measured. The last part of this work was focused on measuring the insertion loss of EMI filters. The main task was to compare the impedance systems 1 /100 and 0,1 /100 and vice versa. The insertion loss was measured for several chosen EMI filters. The insertion loss of all filters reached approximately the same values for both impedance systems.
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Vyhodnocení katastrofální povodně v srpnu 2002: Geologické změny v údolních nivách a přilehlém okolí po povodních v srpnu 2002. Část A
Geotest, Brno ; Česká geologická služba, Praha ; Výzkumný ústav vodohospodářský T.G. Masaryka, v.v.i., Praha ; Valigurský, Leoš ; Šebesta, Jiří ; Nývlt, Daniel ; Havlíček, Pavel ; Břízová, Eva
Byly zaznamenány geologické a geomorfologické změny údolní nivy, které nastaly v průběhu povodně. Mapování bylo provedeno v údolní nivě Vltavy pod Kralupy nad Vltavou, Dyje pod Znojmem, v soutokové nivě Ohře a Labe v okolí Terezína a údolní nivě Lužnice pod Suchdolem nad Lužnicí. Výsledky přinášejí podklady pro přípravu rajonizace dílčího nebezpečí, které v daném údolí nivy hrozí a případně pro jejich geotechnologické zajištění a případnou prevenci před ním.
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Vyhodnocení katastrofální povodně v srpnu 2002: Geologické změny v údolních nivách a přilehlém okolí po povodních v srpnu 2002. Část A
GEOTEST ; Česká geologická služba ; Výzkumný ústav vodohospodářský T.G. Masaryka, v.v.i., Praha ; Valigurský, Leoš ; Šebesta, Jiří ; Nývlt, Daniel ; Havlíček, Pavel ; Břízová, Eva
Přílohy obsahují fotodokumentaci, terénní dokumentaci k části A, paleopedogenické zhodnocení, georadar, literární rešerši a samostatnou zprávu Paleoekologické aspekty pramenných oblastí a údolních niv.
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