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Special Methods for Microwave Vector Measurements
Urbanec, Tomáš ; Svačina, Jiří (advisor)
Theoretical principles of the sixport measurement method are presented. Description of theoretical design and influence of its parameters on measurement precision follows. Simple sixport measurement system was made and its parameters are described. As the main thesis contribution there is described a new approach to method with more detectors in the system. Mean features are more valid sixports at one specific frequency and frequency bandwidth aviable up to 1 : 100 and more. Such a wideband measurement system was designed for the frequencies between 50 and 2680 MHz and its parameters are presented in the work.
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Creation of laboratory exercises focused on measurement of basic parameters of telecommunication cables
Mlatec, Jan ; Látal, Michal (referee) ; Münster, Petr (advisor)
This bachelor thesis is focused on getting acquainted with the basic parameters of telecommunication lines. The laboratory is equipped measuring equipments used to measure. First, the individual cables were connected to the measuring instruments. This was followed by the launch of the devices and a detailed acquaintance with their functions. After obtaining the requisite knowledge of the device, a manual was prepared, which describes the working procedure for working with measuring equipments. The attachment which is a part of the thesis contain the model design of the individual laboratory tasks. Each of these exercises contains extensive theoretical introduction to solve problems and task assignment. First, the individual cables were connected to the measuring instruments. This was followed by the launch of the devices and a detailed acquaintance with their functions. After gaining the necessary knowledge about the device, an abbreviated manual was prepared, which describes the work procedure of measurement work, which is in the appendix to this work. Furthermore, a design of laboratory tasks for students was performed. This work contains a sample elaboration of individual laboratory tasks. The first task was created to measure the attenuation characteristics of coaxial cables. Students will learn how the attenuation of individual types of cables are different. The second task is to measure the frequency dependence of the impedance of coaxial cables. Students will again check the important characteristics of individual types of coaxial cables. The third task is to measure the parameters of UTP cables that will make students able to compare the properties with another type of cable.
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Basic measurement on the Vector network analyzer
Lapčík, Josef ; Urbanec, Tomáš (referee) ; Dřínovský, Jiří (advisor)
This bachelor project concerns with a vector network analyzer for measurement of reflection coefficient, carry coefficient and scattering coefficients. Main parts of vector network analyzer and principle of analyzer with relation to possible areas of error correction are described. Possibilities of using modern vector network analyzer are shown in relation to their conception. Second part of the project deals with design of filters and directional coupler designed for measuring on analyzer. Designs of lowpass filter, bandpass filter and branch-line directional coupler are describe in details. Results of filters analysis from program Ansoft Designer and results of measurement on vector network analyzer are appended. The last part of project focus on creation of application for automatic measurement on network analyzer in program interface Agilent VEE.
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Automatic antenna analyser
Dufek, Ivo ; Šebesta, Jan (referee) ; Lukeš, Zbyněk (advisor)
This project is dealing with methods of measuring impedances of the antenna systems in the frequency range from the low frequencies to the very high frequencies. There is a discussion about different methods of measuring impedance and each technique is critically evaluated. In terms of this project is compared few types of the professional antenna analyzers. According to this comparison there was made the concept of my own antenna analyzer. There is a detailed description of the design of this device’s important parts including software equipment. Designed instrument has been built and tested.
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Miniature antenna for mobile applications
Šmarda, Marek ; Švanda,, Milan (referee) ; Pokorný, Michal (advisor)
This work deals with the most famous constructions of planar antennas. The work analyses selected methods of connecting planar antennas' charging with the possibility of impedance adaptation. An important part of the work consists of description of techniques for increasing bandwidth and conversely techniques for reducing the dimensions which are important for the design of planar antennas for mobile devices. The antennas were designed by means of theoretical basis and their properties were examined in the electromagnetic field simulator. The selected antenna model was constructed and its parameters were measured experimentally. The matching circuit for the antenna to tune it to different resonant frequencies was designed and constructed.
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Improving antenna parameters by the application of metamaterials
Šporik, Vladimír ; Hertl, Ivo (referee) ; Raida, Zbyněk (advisor)
The thesis is focused on the design of a planar resonant-type antenna, which exploits a proper combination of left- and right-handed properties of transmission lines. This transmission line is called CRLH TL and is based on Sievenpiper mushroom structure. Advantages of the proposed antenna concept are demonstrated by a detailed comparison of its basic properties with the properties of a conventional patch antenna.
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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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Smith Chart Visualization Tool
Marek, Martin ; Pokorný, Michal (referee) ; Kadlec, Petr (advisor)
The objective of my bachelor thesis was to create a Smith chart visualization tool in computing environment MATLAB. I created an impedance Smith chart in graphical user interface which delineate parameters of basic line types. Parameters of transmission lines can be defined in the Smith chart as normalized impedance, reflection coefficient, normalized admittance or impedance in combination with line’s characteristic impedance. It is also possible to design simple matching circuits, e.g. with quarter-wave transformer, series stub, parallel stub or matching circuits with lumped elements.
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Design of circular polarized antenna for 2.4 GHz
Hase, Michal ; Lukeš, Zbyněk (referee) ; Láčík, Jaroslav (advisor)
In this thesis, I introduce two types of circularly polarized rectangular microstrip antennas at 2.44 GHz. First type has direct fed and the second has two inputs for fed. In first case is used a stub to make the frequency with minimum return loss and equal to the frequency with minimum axial ratio. In second case is use the power splitter to divide the wave in to two lines with phase shift 90° for feeding the patch. In this thesis is described, how to get the best results of Axial Ratio.
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