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Planar antenna arrays for RFID applications
Pochobradský, Jakub ; Horák, David (referee) ; Lukeš, Zbyněk (advisor)
This thesis describes the basic principles of radio frequency identification, basic characteristics of patch antennas, the possibility of their feeding and design of planar antenna series. Are discussed, impedance matching options. The selected antenna arrays were realised, measuring their parameters was down and measured parameters was compared with simulation results.
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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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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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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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Dualband Antenna for Global Navigation Satellite System
Mikulášek, Tomáš ; Lukeš, Zbyněk (referee) ; Láčík, Jaroslav (advisor)
This master’s thesis introduces to the reader with a modern antenna type the microstrip patch antennas. The most common types of microstrip antennas and their parameters and feeding methods are introduced in the theoretical section of this master’s thesis. This section deals with the circularly polarized microstrip antennas. Design of an active dual-band circularly polarized antenna for global navigation satellite application in the AWR Microwave Office is presented in the practical section. The proposed single-fed dual-band circularly polarized design is achieved using two stacked square microstrip patches. The antenna operates at the L1 + E1 and L5 + E5a frequency bands. Antenna preamplifier consists of a low-noise transistor and a dual-band band-pass filter. The thesis describes realization and measurement results of the dual-band antenna performance in the anechoic chamber. Measured results of the preamplifier performance are presented.
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Reconfigurable patch antenna
Zlatníček, Radek ; Polívka, Milan (referee) ; Raida, Zbyněk (advisor)
The master's thesis deals with the design and implementation of a reconfigurable patch antenna. The antenna is fed by a microstrip transmission line. To the microstrip feeder, tuning stubs are connected. Each stub matches the input impedance of the antenna to 50 ? for different operation frequencies. Stubs can be individually connected to the feeder by PIN diodes; operation frequency of the antenna can be switched that way. In the project, the antenna is initially designed for antenna substrate RO3006. Then, the design will be converted to the substrate ARLON AD600 selected for the realization. In the project, modifications of stubs will be proposed to properly connect the PIN diodes. Functionality of the designed antenna will be verified by modeling in Ansoft Designer. The last part will be dealt with implementation of the antenna and the experimental measurement of their properties.
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Harvesting of emelctromagnetic energy in 24 GHz band
Rokos, Lukáš ; Pokorný, Michal (referee) ; Raida, Zbyněk (advisor)
The thesis describes basic principles of an electromagnetic energy harvesting and its potential use. To gain the energy, a rectenna (rectifying antenna) is selected. The rectenna consists of a patch antenna, a matching circuit and a rectifier circuit. The thesis describes a design of the patch antenna operating at 24 GHz and its matching to the microstrip line with the characteristic impedance 50 . Then, the circuit for matching the rectified is designed using an open-ended stub. The last part of the thesis describes several types of rectifier circuits to be used potentially. Functionality of the designed rectenna has been verified in ANSYS Designer.
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Computer modeling of implantable antennas
Deneš, Roman ; Kadlec, Petr (referee) ; Raida, Zbyněk (advisor)
The thesis deals with a design of planar antennas and their simulation in the vicinity of a human body. The main goal of this thesis is parametrically analyse different types of planar antennas and find out which one possesses the highest quality in the vicinity of a human body. The design and simulation were made in a software called CST Microwave Studio. Firstly, the attention is paid to the concept of designing and simulation. Further, they are made and tested.
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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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Retrodirective antenna array
Šindler, Pavel ; Morávek, Ondřej (referee) ; Pokorný, Michal (advisor)
In the first part of this thesis a basic theory of retrodirective antenna arrays and their particular parts – antennas and mixers is summarized. Further, there is a basic summary of possibilities for an usage of retrodirective antenna arrays for an information transmission. The second part deals with the concrete retrodirective antenna array design. The design starts with creation of an antenna array model for MATLAB software. Then a suitable structure for further design is chosen. Further, particular parts of retrodirctive antenna array – a patch antenna, a mixer, a low-pass filter, a bandstop filter, a signal combiner and a Wilkinson power divider are designed and analyzed in Ansoft Designer software. For the patch antenna analysis also CST Microwave Studio software is used. The following part deals with the realization of particular parts of the retrodirecive antenna array and its parameters measuring.
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