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Textile SIW Rectangular Ring-slot Antennas for Off-body Communication
Vašina, Petr
In this paper, a textile SIW rectangular ring-slot antenna for the ISM frequency band 5.8 GHz is proposed. The antenna radiates a linearly polarized wave with the maximum radiation in the perpendicular direction to the antenna plane. The antenna is fabricated on the soft-shell fabric in the two versions. In the first version, the conductive layers were fabricated by a self-adhesive copper foil. In the second version, the conductive layers were fabricated by the screen printing on a foil ironed on the soft-shell fabric. Experimental results prove that the proposed antenna fabricated by copper foil achieves the impedance bandwidth of 3.1 % for the reflection coefficient less than -10 dB and the gain of 6.91 dBi. While screen printing antenna achieves the impedance bandwidth of 2.93 % for the reflection coefficient less than -10 dB and the gain of 7 dBi, respectively.
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Textile Microwave Components
Hotovec, Jakub ; Láčík, Jaroslav (referee) ; Vašina, Petr (advisor)
This bachelor thesis is focused on possibilities of designing components integrated on substrate, where substrate is fabric. It contains theoretical information about the SIW structure, measurement of dieletric parameters of three fabrics, design, synthesis and production of waveguide, a three port divider and a band-pass filter on three substrates. For simulation CST Microwave Studio is used
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Proposal for Project Management of Contract Activities
Vašina, Pavel ; Zima, Petr (referee) ; Jurová, Marie (advisor)
This bachelor thesis deals with the design of process management activities in a company which is focused in designing gas, aqua and electricity activities.The first part of the bachelor thesis is focused on information about the company. The second part explains the theoretical basis. The following part analyzes the current state of the company followed by the last part which is focused on the proposal of the order improvement in terms of delivery dates, quality and costs.
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3D printed microstrip patch antenna
Medek, Petr ; Vašina, Petr (referee) ; Láčík, Jaroslav (advisor)
The bachelor thesis deals with the issue of inhomogeneous substrates of microwave patch antennas. The aim of this work was to find such a distribution of the permittivity of the substrate of a linearly polarized patch antenna, which would be possible to achieve an extension of the impedance bandwidth to an antenna with the same effective permittivity. The investigated patch antenna has a square shape, is linearly polarized, and is powered by a coaxial power supply. Few types of permittivity distribution are presented and compared with an antenna with a substrate with an adequate effective permittivity. For each antenna, the dimensions of the patch are adjusted so that the antenna is designed at a medium frequency of 2.45 GHz. Furthermore, an antenna with a constant permitivity with patch dimensions is designed and the permittivity of the substrate is adjusted so that the required frequency is achieved. In the two investigated styles, we observe an extension of the impedance bandwidth to the antenna with adequate effective permittivity in the order of hundreths of percent, which was subsequently verified by manufacturing and measuring.
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RESONANT AND QUASI-RESONANT SWITCHMODE POWER SUPLIES
Vašina, Petr ; Sedláček, Jiří (referee) ; Murina, Milan (advisor)
This project focuses on issues and solutions to switch mode power suplies. The first part discusses comparison of analog and switching power supply stabilized, and their essential involvement. Further addressed the concept of peripheral participation resonant switch mode power suplies. This chapter is progressively designed input circuit, the main part of the switching resources, output circuit and feedback circuit comparison. At the end of the project is the komplete wiring diagram with a list of used parts. Under the proposal was designed printed circuit, is characteristics were measured.
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Human activity detection in indoor spaces via WLAN network
Sekanina, Tomáš ; Vašina, Petr (referee) ; Miloš, Jiří (advisor)
Bachelor thesis represents possibilities of use WLAN network and standard IEEE 802.11n for object or human detection in a room with different scenarios. Bachelor thesis includes a theoretical description of WLAN network and family of WLAN standards IEEE 802.11 with detailed focus on standard IEEE 802.11n and its physical layer. Attention is also paid to the wave propagation inside buildings. It also includes description of measuring Wi-Fi INTEL 5300 NIC, CSI Tool 802.11n and controlling measuring NIC in operating system Linux. In practical part is demonstrated analysis of high-throughput packets using standard 802.11n. Results of measurement of object and human detection in a room are exported to programming language MATLAB and there are analyzed. Results of experiments are discussed in conclusion of bachelor thesis.
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Modeling of antennas for communication near human body
Hodulák, Lukáš ; Hebelka,, Vladimír (referee) ; Vašina, Petr (advisor)
The bachelor thesis deals with problems of body-centric communications. The thesis also deals with the design of Yagi-Uda antenna with power supply substrate integrated waveguide structure (SIW) with the operating frequency of 60 GHz. The thesis is divided into a description of antennas and body-centric communications, description of Yagi-Uda antenna, types of Yagi-Uda antennas, the substrate integrated waveguide and SIW power divider. Then the thesis deals with selected Yagi-Uda antenna, transition between SIW and rectangular waveguide WR-15, antenna array and simulations in CST Microwave Studio. The last part of the thesis is a proposal itself, measurement and comparison of results measured with simulated ones.
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Wearable Antennas Operating in the ISM Band
Zapletal, Ondřej ; Hebelka,, Vladimír (referee) ; Vašina, Petr (advisor)
Presented thesis is oriented on wearable antennas. The main aim of this thesis is to introduce the basic properties, measurement of textile’s electric properties and several manufacturing methods. The antenna design for the ISM 5.8 GHz bandwidth is also included and further observed by numerical model in CST Microwave Studio. The impact of flexibility and the influence of human tissue are evaluated in the case of designed equipment. According to the optimized design was made several samples by various technologies and samples were measured. Achieved results are further compared to equivalent results listed in actual available references.
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Double ridge horn antenna for antenna measurement
Vašina, Petr ; Hertl, Ivo (referee) ; Láčík, Jaroslav (advisor)
The thesis deals with broadband antennas for measurement purposes. A ridged horn antenna has been selected for this concept, designed for the frequency range 0.9 GHz to 9 GHz. This work contains general theoretical description of antennas and further it focuses on a specific design of the ridged horn antenna, beginning with the calculation of its dimensions, modeling and optimization to obtain desired antenna properties. Finally, the antenna was constructed and measured. The reflection factor s11
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Wearable antenna operating in proximity of human body
Jakubíček, Marek ; Pokorný,, Michal (referee) ; Vašina, Petr (advisor)
This thesis describes the possibilities of wearable antennas and the basic properties description. Numeric model for ISM 2,4 GHz band is created by CST Microwave Studio®. The thesis also deals with the human body proximity effect by two models of human tissue. The effect of flexibility to antenna parameters is evaluated. Several samples of the antenna has been created and measured. Obtained results has been compared with numeric model and with the literature.
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