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Electronic Components in Textile Substrates
Kokolia, Martin ; Joler,, Miroslav (referee) ; Dražan, Libor (referee) ; Raida, Zbyněk (advisor)
Cílem této práce je popsat současný stav v oblasti mikrovlnných komponent na bázi textilu a poté také autorův příspěvek k výzkumu. V tomto studijním oboru je třeba řešit mnoho problémů, a proto jsou stanoveny velmi konkrétní cíle, které by měly tvořit kompletní komunikační systém, který by byl snadno integrovatelný do čalounění uvnitř letadla nebo jiného vozidla. První kapitola je zaměřena na použití relativně nízkofrekvenčních obvodů v pásmu UHF a vysokofrekvenční sklízení energie. Po simulacích následují praktická měření. Další kapitola charakterizuje nové 3D pletené textilie a jejich vysokofrekveční vlastnosti a modelování na velmi vysokých frekvencích, které jsou žádoucí pro užití jako komunikační kanály. S prakticky ověřeným a numericky popsaným textilním substrátem pro použití v pásmu SHF je představena nový vlnovod integrovaný do textilu na bázi tisknutelného umělého magnetického vodiče s praktickou metodikou návrhu. Po ověření byl vlnovod použit pro základní dělič výkonu, dvě různé antény a dva typy senzorů. Všechny návrhy byly vyrobeny a testovány s uspokojivými výsledky.
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Radar sensors for speed measurements
Doležal, Tomáš ; PhD, Jaroslav Čechák, (referee) ; Kokolia, Martin (advisor)
The main topic of this bachelor thesis is selecting a suitable microwave sensor for measuring the speed of vehicles in regular traffic, while covering multiple road lanes by a suitable method. Furthermore, the optimal one is selected in the form of search, based on the necessary parameters from commercially available radar sensors measuring primary speed. In the next step, simulation is performed for the selected speed sensor in the MATLAB environment, depending on its parameters and the modes in which it can work. The simulation also includes environmental influences on the received signal. There is introduced programmed graphical user interface for simulating a lot of situations on the road for two cars in the next section. Last section summarizes results of real measurement.
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Network for high-frequency on-body communication
Halas, David ; Láčík, Jaroslav (referee) ; Kokolia, Martin (advisor)
This work focuses on the design of a network for high-frequency communication on the human body. The thesis is focused on the design of two-band antennas, namely 2.4 GHz and 5.8 GHz. The antenna is integrated into the textile and works close to the human body. The introduction describes the problem of spreading electromagnetic waves along the human body. Further, the thesis deals with the applicability of different types of antennas for integration on the textile substrate. Based on the simulations performed, a suitable antenna is selected for the purpose. The simulation program used is the CST Microwave Studio. In the end, the antennas were optimized, subsequently manufactured and their parameters measured.
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Waveguide slot antenna for 10.5 GHz band integrated into the textile substrate
Sekanina, Jiří ; Láčík, Jaroslav (referee) ; Kokolia, Martin (advisor)
Bachelor thesis deals with the design of waveguide slot antenna for the 10,5 GHz frequency integrated in the textile substrate. The first part contains a general theory of transmission lines. The second part describes the design of a waveguide slot antenna. The third part contains procedures for designing a SIW slot antenna and the fourth part describes the design of 3x2 antenna array that is integrated into 3,4 mm thick textile with relative permittivity r = 1,2 with greater main lobe width requirements and side lobe suppression. The last part summarizes the results.
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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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Guitar electron-tube amplifier
Kokolia, Martin ; Petržela, Jiří (referee) ; Kratochvíl, Tomáš (advisor)
The objective of this bachelor’s thesis was to design a low-frequency tube amplifier optimized for use with electric guitar. The preamp is equipped with ECC83 triode tubes as voltage amplifier and cathode follower for connection with a simple frequency corrector. The output of the FX loop allows the connection of external effects. The power amplifier is realized by dual-action 6L6 tubes and phase invertor with ECC81 triode. Output transformer allows impedance matching for speakers. The power supply uses a GZ34 rectifier tube and diode bridges. Text of thesis also includes theoretical design of guitar tube amplifier and documentation of realization of functional prototype.
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Electronic Components in Textile Substrates
Kokolia, Martin ; Joler,, Miroslav (referee) ; Dražan, Libor (referee) ; Raida, Zbyněk (advisor)
Cílem této práce je popsat současný stav v oblasti mikrovlnných komponent na bázi textilu a poté také autorův příspěvek k výzkumu. V tomto studijním oboru je třeba řešit mnoho problémů, a proto jsou stanoveny velmi konkrétní cíle, které by měly tvořit kompletní komunikační systém, který by byl snadno integrovatelný do čalounění uvnitř letadla nebo jiného vozidla. První kapitola je zaměřena na použití relativně nízkofrekvenčních obvodů v pásmu UHF a vysokofrekvenční sklízení energie. Po simulacích následují praktická měření. Další kapitola charakterizuje nové 3D pletené textilie a jejich vysokofrekveční vlastnosti a modelování na velmi vysokých frekvencích, které jsou žádoucí pro užití jako komunikační kanály. S prakticky ověřeným a numericky popsaným textilním substrátem pro použití v pásmu SHF je představena nový vlnovod integrovaný do textilu na bázi tisknutelného umělého magnetického vodiče s praktickou metodikou návrhu. Po ověření byl vlnovod použit pro základní dělič výkonu, dvě různé antény a dva typy senzorů. Všechny návrhy byly vyrobeny a testovány s uspokojivými výsledky.
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Artificial Magnetic Conductor-Based Microwave Button On Textile Substrate
Kokolia, Martin
This paper is proposing textile substrate-integrated button composed of textile integrated waveguide. Such pressure sensor could be used as an interface button or as a sensor of person presence. Proposed structure consists of two layers of substrate. Lower one is a straight section of the waveguide with slots feeding upper one is a closed section of waveguide forming a resonator stopband filter. Later, the simple textile integrated waveguide is changed to waveguides utilizing periodic cells as the artificial magnetic conductor (AMC) which could be printed instead of sewing vias by metallic wires.
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Textile-Integrated Rf Energy Harvester
Kokolia, Martin
In the paper, we present a dual-band wearable rectenna operating in 900 MHz GSM band and 2.45 GHz ISM band. The rectenna was designed as a multilayer structure to reduce size while having a large enough aperture with a reasonable gain. The antenna was connected to the rectifier by a current probe via a textile substrate. The rectifier was conceived as a voltage doubler to maximize voltage on a load even with a very low received power. The manufactured antenna showed the gain 6.3 dBi at 900 MHz and 2.8 dBi at 2.45 GHz. The rectifier operated from -20 dBm and was measured up to -2 dBm with 19% efficiency for the GSM band and 17% efficiency for the ISM band.
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Network for high-frequency on-body communication
Halas, David ; Láčík, Jaroslav (referee) ; Kokolia, Martin (advisor)
This work focuses on the design of a network for high-frequency communication on the human body. The thesis is focused on the design of two-band antennas, namely 2.4 GHz and 5.8 GHz. The antenna is integrated into the textile and works close to the human body. The introduction describes the problem of spreading electromagnetic waves along the human body. Further, the thesis deals with the applicability of different types of antennas for integration on the textile substrate. Based on the simulations performed, a suitable antenna is selected for the purpose. The simulation program used is the CST Microwave Studio. In the end, the antennas were optimized, subsequently manufactured and their parameters measured.
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