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Laser source with fiber-optic output
Roupec, Tomáš ; Mikulka, Jan (referee) ; Drexler, Petr (advisor)
This term project deals with the semiconductor laser components, and how it works. Additionally, there is an optical fiber ant networking with laser. It is written of power and cooling laser diodes and such information suggested the possible involvement of the laser diode. At the end of this work is designed laser´s exciter with charging and adjacent circuits.
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Fast signal processing
Rychlý, Ivo ; Langerová, Petra (referee) ; Mikulka, Jan (advisor)
Zvětšující se množství dat v moderním zpracování obrazu vyžaduje nový postupy v psaní algoritmů. Největší překážkou pro úspěšné zrychlení algoritmu je paralelizace a následná optimalizace. Programy jako CUDA a OpenCL s modifikovaným programovacím jazykem a rozhraním pomáhají s tímto problémem a otevírají paralelní zpracování širšímu okruhu lidí. V této práci zabývám základy zpracování obrazu a tomu jak paralelizace algoritmů může urychlit zpracování obrazu.
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Digital oscilloscope with AVR
Stejskal, Martin ; Mikulka, Jan (referee) ; Friedl, Martin (advisor)
The aim was got acquainted with microcontrolers from ATMEL family and study on wthat principes works analog and digital osciloscopes. On base of this informations, block design was made of digital osciloscope with microcontroler ATMEL from family AVR. The following chapters were look for a solution of input circuits with A/D convertor, witch transform analog signal to digital. Then, the digital signal is processed another circuits. Extended part of this work is software, witch must also controll data protocols and data security.
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Construction of an impedance analyzer
Slinták, Vlastimil ; Smékal, Zdeněk (referee) ; Mikulka, Jan (advisor)
The aim of this master’s thesis is to build stand-alone impedance analyzer for mesasuring antennas’ impedance. The vector network analysis is used as measuring method. Analog (with directional coupler and gain and phase detector) and digital (with 8bit AVR microcontrollers) part of analyzer are described and then build.
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Cellular Network Coverage Model
Unzeitig, Lubomír ; Mikulka, Jan (referee) ; Gleissner, Filip (advisor)
This work deals with a mobile signal propagation in electromagnetic wave form in a real environment of city microcell. The electromagnetic wave passing through the city environment is affected by many kinds of mechanism. It includes especially diffraction along vertical edges of buildings, diffraction across building roofs and buildings or ground refraction. These mechanisms are time variable. If we want to predicate them, we have to use sort of approached model. For an experimental part of this work, the Berg’s recursive model with a possibility of path loses or signal level prediction in a selected microcellular system is chosen. The software for a cellular network coverage is created on the basis of this fact. Its advantage is a possibility of up to five base stations placing and many kinds of settings, e.g. operating frequency, base station transmitting power, base and mobile station antennas height etc. There is a possibility of system GSM 900, GSM 1800 or UMTS choice. The Berg’s recursive model features are checked by simulations on experimental and real maps of build-up area.
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Wireless doorbell with digital voice transmission
Partsch, Patrik ; Šebesta, Jiří (referee) ; Mikulka, Jan (advisor)
The master´s thesis deals with a design and layout of wireless doorbell with digital voice transmission. It also includes the nRF9E5 circuit analysis. In the beginning of the document there is characterization of the problem in general. Next part describes a layout example for the application schematic, a layout of printed circuit board and a layout of software. nRF9E5 is a true single chip system with fully integrated RF transceiver, 8051 compatible microcontroller and a four input 10 bit AD converter. Despite of all studies of available literature I have found only very little particular information related to this matter. In general, the main aim of this work is to make the wireless doorbell with digital voice transmission. Further, ilustrated schematics are enclosed as a attachement of this thesis.
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Methods for evaluation of quality of automotive filters
Sedlák, Jiří ; Drexler, Petr (referee) ; Mikulka, Jan (advisor)
This bachelor thesis deals with theoretical research, description and design of three individual methods of defective air filters detection. Individual methods are described and compared in terms of their technical difficulty and expected efficiency. These methods are optical test, acoustic test, pressure test and the method of detection of gas CO2. All researched methods were proved practically and the measurements of detection of defective air filters were taken. The defect of air filter was detected by use of optical test.
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Operating parameters of LED light sources
Janík, Daniel ; Mikulka, Jan (referee) ; Havlíková, Marie (advisor)
The aim of the thesis is to introduce the basic photometric quantities and operating parameters of LED light sources, according to which the light sources are evaluated and compared. The thesis examines effects of high temperature and elevated stress on LED retrofits and a design of measurement methods to measure these influences. According to the proposed methods, nine samples of light sources were measured and compared to each other on a basis of the measurements. Comparison was made from the point of view of the energy as well as the quality of the produced light. The results were also compared to the parameters specified by the producers.
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Laser source with fiber-optic output
Roupec, Tomáš ; Mikulka, Jan (referee) ; Drexler, Petr (advisor)
This term project deals with the semiconductor laser components, and how it works. Additionally, there is an optical fiber ant networking with laser. It is written of power and cooling laser diodes and such information suggested the possible involvement of the laser diode. At the end of this work is designed laser´s exciter with charging and adjacent circuits.
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WLAN and Bluetooth Systems Coexistence
Mikulka, Jan ; Hanus, Stanislav (advisor)
The dissertation thesis deals with a WLAN and Bluetooth systems coexistence. A Bluetooth standard works in an unlicensed frequency band 2,402 – 2,480 GHz. This frequency band is also used by an IEEE 802.11b/g standard (Wi-Fi) which is the most extended representative of WLAN networks. Because Bluetooth and Wi-Fi systems operate in the same frequency band, a mutual signal degradation may appear, when devices are collocated in the same area. In the first part of the dissertation thesis there is a brief summary of 2,402 - 2,480 GHz frequency band regulations and its usage. There are described physical layers of Bluetooth and IEEE 802.11b/g standards and techniques used for a collision avoidance. The main part of the dissertation thesis deals with a development of a new Matlab Simulink model for investigations of the Bluetooth and Wi-Fi standards coexistence. Physical layer models and results of the coexistence simulations are verified by a measurement in real conditions with a help of a modern vector signal analyzer. The results are presented in a graphical form and a brief summary is attached at the end of each chapter. Corresponding tables of simulated and measured values are available in the enclosed CD.
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