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Wave propagation in homogeneous line
Brázda, Daniel ; Steinbauer, Miloslav (referee) ; Friedl, Martin (advisor)
This work deals with the propagation of electromagnetic waves. In the theoretical section describes the propagation of waves in the open space and the line. The main objective of this work is to design a new layout laboratory exercises in which students measure the behavior of waves on a homogeneous line. The design include measuring the standing wave ratio (SWR) using the digital SWR meter, measure the voltage measured along the line and measuring the frequency dependence of the input impedance of the line.
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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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Superconductivity in the fourth state of matter
Mádrová, Tereza ; Klíma, Miloš (referee) ; Fiala, Pavel (advisor)
This master thesis is focused on description and research of electromagnetic waves in plasma state. Some simple cases of no-loss mode distribution of electromagnetic waves in plasma are known, for example around the coaxial cable. In other words, the properties of superconducting state in materials are shown. This view of plasma properties can significantly help to clarify observed phenomena in experimental plasma research or to outline new trends in plasma usage in this mode. The introduction and the theoretical parts describe the known theory related to the propagation of electromagnetic waves in a non-homogeneous or anisotropic environment, in the next parts of the thesis the mathematical model of the solved problem of wave propagation in plasma is mentioned and the design and realization of the experiment is followed. The model includes processing of Maxwell's reduced equations in Haeviside notation for the state of matter referred to as plasma, the design of a model for numerical modeling and analysis, and the design of a simple experiment to verify numerically analyzed results.
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Mobile workplace for field strength measurement
Gašpierik, Andrej ; Urbanec, Tomáš (referee) ; Láčík, Jaroslav (advisor)
The aim of this work is how to construct mobile workplace for automated field strength measurement in depending on the distance from transmitter. This is a very sophisticated device. It can be used during covering buildings wi-fi or GSM. DEPARTMENT OF RADIOELECTRONICS FEKT VUT in Brno is going to use this workplace on lessons of subject Proposal antennas and radio links. This thesis summarizes the problematics of extension and measurement of electromagnetic waves, pissibilities of measuring the distance, communication between microcontroller ATmega16 and notebook via USB bus, data reading from the spectrum analyzer and the precessing of these results in the user interface. The whole device that can render how changes signal power at increasing distance from the source of the signal has been designed and tested.
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Simulator of partial discharge signal in the UHF band
Škoda, Martin ; Kasárník,, Milan (referee) ; Drexler, Petr (advisor)
This master thesis deals with the problem of the origin and expression of partial discharges in dielectric materials. In the thesis the theoretical foundations, types and parameters of partial discharges are described. In particular, it deals with UHF (ultra high freqeuncy) electromagnetic radiation using UHF method of partial discharge detection. It also deals with the partial discharge UHF signal simulation. The development of UHF sensor systems for partial discharges requires a dive that can simulate them as accurately as possible. Furthermore, a workplace was designed for simulation and detection of partial discharges and processing of their time and frequency characteristics.
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Exploatation of VHF, UHF, SHF, and EHF frequency bands in civil & military aeronautic radars (handbook)
Jasimová, Rafah ; Šplíchal, Miroslav (referee) ; Vosecký, Slavomír (advisor)
VHF, UHF, SHF, EHF, radar, wave propagation, electromagnetic wave, active radiolocators, passive radar system
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Superconductivity in the fourth state of matter
Mádrová, Tereza ; Klíma, Miloš (referee) ; Fiala, Pavel (advisor)
This master thesis is focused on description and research of electromagnetic waves in plasma state. Some simple cases of no-loss mode distribution of electromagnetic waves in plasma are known, for example around the coaxial cable. In other words, the properties of superconducting state in materials are shown. This view of plasma properties can significantly help to clarify observed phenomena in experimental plasma research or to outline new trends in plasma usage in this mode. The introduction and the theoretical parts describe the known theory related to the propagation of electromagnetic waves in a non-homogeneous or anisotropic environment, in the next parts of the thesis the mathematical model of the solved problem of wave propagation in plasma is mentioned and the design and realization of the experiment is followed. The model includes processing of Maxwell's reduced equations in Haeviside notation for the state of matter referred to as plasma, the design of a model for numerical modeling and analysis, and the design of a simple experiment to verify numerically analyzed results.
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Simulator of partial discharge signal in the UHF band
Škoda, Martin ; Kasárník,, Milan (referee) ; Drexler, Petr (advisor)
This master thesis deals with the problem of the origin and expression of partial discharges in dielectric materials. In the thesis the theoretical foundations, types and parameters of partial discharges are described. In particular, it deals with UHF (ultra high freqeuncy) electromagnetic radiation using UHF method of partial discharge detection. It also deals with the partial discharge UHF signal simulation. The development of UHF sensor systems for partial discharges requires a dive that can simulate them as accurately as possible. Furthermore, a workplace was designed for simulation and detection of partial discharges and processing of their time and frequency characteristics.
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