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Wearable rectifying antenna for RF energy harvesting
Kokolia, Martin ; Horák, Jiří (referee) ; Láčík, Jaroslav (advisor)
The aim of this thesis is to design and rectena that would be able to integrate into a cloth thanks to use of textile substrate. The first part deals with the possibilities of using various communication channels and services for maximizing the useable power. Attention is focused mainly on the use of textile materials for implementing microstrip circuits. It is made valorization of all the typical characteristics and problems using different fabrics as a microwave substrate and the possibilities of realization of conductive structures of microwave patch antenna and microstrip circuits. At the second part are identified parameters and constraints used for the design of the overall device with a rectifying antenna, which will be after the verification of the function in real implementation used for the final concept using textile structures. The design is verified by simulations by CST Microwave Studio and Microwave Designer. The initial design is being gradually extended by other concepts, the use of other materials and technologies. Several design are made, their properties evaluated and the best ones are then compared based on real measurements.
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Modeling and optimization of patch antennas
Šídlová, Ludmila ; Láčík, Jaroslav (referee) ; Raida, Zbyněk (advisor)
This work is engaged in modeling of patch antennas. It describes various types of synthesizing the layout and designing the microstrip feeder or probe feeding. This work is focusing on modeling and creating a patch antenna for 6 GHz fabricated from ARLON 25N and fed by a microstrip. The layout is first calculated from required antenna parameters and substrate parameters. The optimization of the patch antenna is carried out in the program ANSOFT Designer, which analyzes planar structures by the moment method. The fabricated patch antenna is measured by a vector analyzer. Results of measurements and computations are compared in terms of frequency response of the standing wave ratio for the frequency interval from 5.5 to 6.5 GHz. The patch antenna is also modeled in the program COMSOL Multiphysics as a two-dimensional conical monopole with a coaxial feeding, and a three-dimensional patch fed by a microstrip; the design is optimized for the operation frequency 6 GHz.
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SIW fed Yagi antenna
Jakubíček, Marek ; Láčík, Jaroslav (referee) ; Všetula, Petr (advisor)
This thesis describes the design of Yagi-Uda antenna on the frequency of 12 GHz situated on suitable substrate. The thesis also deals with the design of the substrate integrated waveguide which is used as an antenna feeder. The thesis is divided to the theory, design of the substrate integrated waveguide, design of the planar Yagi antenna and the waveguide to antenna connection. The next step is an analysis of the created structure by CST Microwave Studio® design software, eventual structure adjustment, realization and behavior verification.
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Radiation of antenna array in near-field area
Hermany, Jiří ; Láčík, Jaroslav (referee) ; Nováček, Zdeněk (advisor)
The aim of my diploma thesis is to analyze the antenna array radiation and to produce the antenna array radiation computation program. The program should display the electric and magnetic intensity and radiation power density distribution over the planar or cylindrical surface in the near-field area. The antenna array analyzed in this paper consists of a number of elementary dipoles placed in a row with a reflector which represents the conductive board situated in parallel to the row of dipoles. The demonstration program was built in MATLAB and allows computing and displaying the computed values components of antenna array radiation on the planar or the cylindrical surface. The program also allows saving computed values, saving displayed graphs, or saving the adjusted parameters of antenna array. The created program can be used for the presentation of the antenna array radiation in a school laboratory or for the graphical representation when a new antenna is designed.
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3D printed dielectric resonator antenna
Lungu, Masauso ; Láčík, Jaroslav (referee) ; Zechmeister, Jaroslav (advisor)
Tato bakalářská práce se zabývá návrhem a výrobou válcové dielektrické rezonátorové antény pracující na kmitočtové pásmu ISM 5,8GHz. V této práci jsou popsány různé metody buzení antény. V CST Microwave Studio byly navrženy a prozkoumány dva numerické modely válcové dielektrické rezonátorové antény, jeden s koaxiální sondou a druhý se štěrbinovým napajení. Model se štěrbinovým napajení byl poté vyroben technologií 3D tisku a následně byly jeho vlastnosti změřeny a ověřeny simulovanými výsledky.
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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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Modeling of planar antenna loaded with ring resonators
Šrajbr, Michal ; Kovács, Peter (referee) ; Láčík, Jaroslav (advisor)
This bachelor’s thesis is focused on the design of the dual-band printed dipol loaded with split ring resonators. The principal of this antenna is described in the first part. The main focus is on the design and tuning of the split ring resonators on the required working frequency in the CST Microwave Studio program. These results are used for designing dual-band printed dipol loaded with split ring resonators working at resonance frequencies of 1,8 a 2,4 GHz. The simulation of this antenna was performed in the IE3D program Zeland. The designed dual-frequency printed dipole has been manufactured and measured.
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Printed wearable antennas
Trubák, Jan ; Láčík, Jaroslav (referee) ; Raida, Zbyněk (advisor)
The project deals with the design of a planar antenna on a textile substrate. The antenna should operate at the frequency of 5.8 GHz. Parameters of the fabricated antenna are compared with characteristics of the antenna simulated in Ansys HFSS. The best possible match between simulated and measured results is obtained by measuring the relative permittivity of the textile substrate, by calculating optimal dimensions of the layout of the planar antenna and by suitable modifications of the simulation model.
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Microstrip Patch Antennas Fed by Substrate Integrated Waveguide
Mikulášek, Tomáš ; Polívka,, Milan (referee) ; Vlček, Čestmír (referee) ; Láčík, Jaroslav (advisor)
Dizertační práce je zaměřena na výzkum mikropáskových flíčkových antén a anténních řad napájených vlnovodem integrovaným do substrátu (SIW). Využitím vlnovodu integrovaného do substrátu pro napájení mikropáskové flíčkové antény dochází ke kombinaci výhodných vlastností obou struktur. Výsledkem je kompaktní anténní struktura, jejíž napájecí vedení neprodukuje parazitní záření a neovlivňuje tak vyzařovací charakteristiku antény. Práci lze z věcného hlediska rozdělit do dvou částí. První část práce (kapitola 2) je zaměřena na návrh flíčkových antén a jejich navázání na vlnovod integrovaný do substrátu. První dvě navržené flíčkové antény využívají vlnovod integrovaný do substrátu a štěrbinu nebo koaxiální sondu pro buzení lineárně polarizované vlny. Napájení koaxiální sondou je dále použito pro buzení kruhově polarizované flíčkové antény. Za účelem získání širšího pásma osového poměru je navrženo napájení flíčkové antény ve dvou bodech. Funkčnost všech anténních struktur je popsána pomocí parametrických simulací a ověřena realizací a měřením vyrobených prototypů antén. Prezentované napájecí metody představují nový způsob napájení pro mikropáskové antény využívající technologii SIW. Ve druhé části práce (kapitola 3) je pojednáno o implementaci štěrbinou napájené mikropáskové anténní struktury do malých anténních polí o velikosti 2x2 a 1x4. V případě lineární řady je uvažováno amplitudové rozložení pro optimální potlačení postranních laloků. Obě navržené anténní řady jsou ověřeny měřením a v porovnání s podobnými anténními řadami dostupnými v literatuře dosahují širšího pracovního pásma kmitočtů a vyššího zisku.
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