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Waveguide-SIW transitions
Bednarský, Vojtěch ; Láčík, Jaroslav (referee) ; Špůrek, Jan (advisor)
This work deals with the design of waveguide transitions. In this work I describe two usually used types of waveguides and that is classical rectangular waveguide with standardized designation WR-10, which is designed for working frequency 94GHz. The second type will be a waveguide integrated into the substrate called SIW. In the first part, numerical models of waveguides are calculated and transitions are created. Numerical models are simulated in CST Microwave Studio. Transitions are constructed in two types. Horizontal transition and orthogonal transition. The results of the first part are obtained dimensions of parameters from numerical models and S-parameters of transition sets.
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Radiation efficiency measurements of dielectric resonator antennas using Wheeler method
Sedler, David ; Mikulášek, Tomáš (referee) ; Mrnka, Michal (advisor)
Bachelor thesis discusses the dielectric resonators as antenna elements. This work includes description field rectangular resonators, possible dielectric materials, shapes and feeds, e.g. coaxial probe, microstrip line or substrate integrated waveguide. In project is listed measuring radiation efficiency of antennas in general and method used wheeler cavity. Bachelor thesis contains design of waveguide with proposal of dielectric resonator. Design of the antenna was conducted in software CST Microwave Studio and there are demonstrated results of simulations. Radiation efficiency of the dielectric resonator antenna was measured by the Wheeler method and the efficiency received from the measured gain. The work included the measured results together with a comparison of the measurements of both methods and simulations.
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Computer modeling of a ridge horn antenna
Lacko, Tomáš ; Lukeš, Zbyněk (referee) ; Láčík, Jaroslav (advisor)
This project includes design and simulation of double ridge horn antenna with frequency range from 1,73 GHz to 14,94 GHz. This work is especially target to calculation proportion of horn for requested gain 20 dB and parameters of double ridge horn antenna. The main aim of project is design of antenna with her computer simulation. Antenna is created and simulated by program CST Microwave Studio.
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Directional antenna for 60 GHz frequency band
Kratochvíl, Jakub ; Pítra, Kamil (referee) ; Láčík, Jaroslav (advisor)
The aim of this diploma thesis is to study the possibilities and problems of low-profile antennas and subsequently to design a directional antenna with spherical reflector for millimeter wavelengths. The theoretical part deals with basic information about horn and reflector antennas, and about SIW technology. In addition, the thesis deals with the specific design and modeling of the antenna using CST Microwave Studio. The simulated design achieved a sufficient bandwidth to cover ISM (57 GHz to 64 GHz) with gain 13.6 dBi at 60 GHz frequency. On fabricated antenna, the antenna impedance ratios were worse and the target bandwidth was not reached. Antenna gain was 14.33 dBi at 60 GHz frequency.
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Antenna for in-car UWB communication
Špůrek, Jan ; Puskely, Jan (referee) ; Raida, Zbyněk (advisor)
This bachelor’s thesis is focused on the design of a wireless UWB network inside a car. The project is divided into three parts. In the first part, we describe the design of suitable antennas and feeding structures. The second part is focused on the simulation of a reciprocal communication for each type of the antenna in free space. In the third part, we investigate the effect of interference caused by near parts of the car for each type of the antenna. The results are then evaluated and the most suitable antenna is chosen for realization. The fourth part describes modifications of the antenna for SMA connector, which is necessary for measurement. In the fifth part we discuss measured results and compare them with assumptions from simulations. Results of the thesis are summarized in the conclusion.
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Design and implementation of TEM cell
Bednarský, Vojtěch ; Růžek, Václav (referee) ; Dřínovský, Jiří (advisor)
The purpose is to design and make a TEM cell, which may often be referred to in publications as a Crawford chamber, after the inventor. The operating frequency is specified from 100 kHz to 400 MHz and is suitable for a test device of maximum size (0,3(l) x 0,3(w) x 0,1(h)) meters. I will first describe the basic methods of electromagnetic susceptibility testing, and electromagnetic interference measurements, and then mention the issues and motivations for the fabrication of the closed TEM cell. Computer simulations were performed in the numerical computing software CST Microwave Studio. The calculated dimensions were used as a starting point for simulation. Dimensions from the simulation were used for the fabrication of the closed TEM cell, which showed similar results as the results of the simulations.
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Patch antenna completed by multiband ground plane
Syrový, Jiří ; Kovács, Peter (referee) ; Láčík, Jaroslav (advisor)
This thesis is aimed on multiband plannar antennas. The features of free stand-alone patch antenna and frequency selective surfaces (FSS) are needed to be investigated. The stand-alone rectangular patch antenna is analyzed in Ansoft Designer. All other results are achieved using CST Microwave studio. The final product is multiband triangle patch antenna with two frequency selective reflectors formed by FSS. The results of particular analysis are compared with theory published in literature.
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Antenna for smart watch
Hájek, Miroslav ; Láčík, Jaroslav (referee) ; Cupal, Miroslav (advisor)
The objective of this work is a create a smart watch antenna, that will operate in two frequency bands. These are GSM (1.8 GHz) and ISM (2.4 GHz) bands. This antenna must be able to work when be placed on an elastic material that is used as a smart watch belt. Antennas options are analyzed and their suitability for given use. There is also an antenna model in CST microwave studio, where all the simulations were made. The antenna is also simulated on human hand models that have different dimensions and tissue ratios.
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Antena integrated to automobile seat
Gulda, Tomáš ; Mrnka, Michal (referee) ; Cupal, Miroslav (advisor)
This thesis is focused on the design of the antenna integrated to automobile seat. Thesis explains the basics of RFID technology, and how RFID works. Especially explains the design of tag, which works in the UHF band. The tag was designed in the CST Microwave studio, where simulations were realized to verify basic properties of the tag such as S11 parameter and directivity. The thesis also contains simulation of the impact of automobile seat on the directivity. Here is the description of how the antenna was made on a textile substrate and here are also measured properties of the antenna.
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Design and optimization of the helical antenna
Zelinková, Lenka ; Olivová, Jana (referee) ; Lukeš, Zbyněk (advisor)
The thesis contains the design of helical antennas for the assigned frequencies. The theoretical design is verified by parameter calculators. The design properties were verified in the computer simulator CST Microwave studio where the antennas were optimized to the maximum gain. The antennas intended as parabola feeds are completed with the designs of parabolas and focal distances between the antennas and the parabolas. Impedance matching by a quarter-wave transformer is designed for the antennas.
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