National Repository of Grey Literature 108 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Circularly polarized antenna array for ISM frequency band 24 GHz
Liyambo, Evans ; Cupal, Miroslav (referee) ; Raida, Zbyněk (advisor)
Tato bakalářská práce se zabývá návrhem a simulací kruhově polarizované anténní řady pro ISM pásmo 24 GHz. Kruhově polarizovaná mikropásková anténa [1] navržená pro práci na kmitočtu 45 GHz byla použita v návrhu anténní řady. Funkce použité antény byla ověřena v programu CST Microwave Studio a její parametry byly porovnány s konvenční flíčkovou anténou buzenou křížovou aperturou. Následně byla anténa modifikována tak, aby pracovala v ISM pásmu 24 GHz.
Sensing signals of a sensor in digestive tract
Raška, Marek ; Láčík, Jaroslav (referee) ; Raida, Zbyněk (advisor)
Wireless capsule endoscopy (WCE) is a system for capturing images of human digestive tract for medical purposes. The antenna is one of the most important parts of the system. In this report, I present a solution for a system operating in the 2.4 GHz and 915 MHz ISM band. The capsule transmitter contains a conformal loop antenna placed on its outer wall. The planar monopole with a partial ground is used as a receiver. The systems have been verified by numerical simulations with a phantom representing digestive tract. The transmitting modules have the bandwidth of several GHz according to simulations. This allows the antenna to tolerate various effects of living tissues. The receiving antennas have the bandwidth of hundreds of MHz. The path loss of the radio link between antennas operating in 2,4 GHz band is lower than 94 dB for any capsule orientation and location. This does not ensure a sufficient signal strength at the receiving antenna. In contrast, the system operating at 915 MHz ensures sufficient signal level at the receiver.
Radar cross section of passenger cars
Hanslík, Radovan ; Pítra, Kamil (referee) ; Raida, Zbyněk (advisor)
This diploma thesis is aimed at radar cross section of passenger cars. Basic scattering parameters of simple targets are described. Selected numeric methods used for computing radar cross section are discussed. Shape and size of simplified vehicle models is investigated. Simulations are verified by computing RCS of objects with well-known characteristics. Radar cross section of Skoda Octavia was simulated using selected numeric methods. Results of all performed simulations are shown in included graphs. Experimental measurment of radar cross section of a vehicle was performed so the measured data can be compared with the simulations.
Wideband low-profile circularly polarized antenna array
Benites Ayala, Jhony Cristian ; Cupal, Miroslav (referee) ; Raida, Zbyněk (advisor)
This bachelor’s thesis is focused on the study of a novel type of wideband low-profile circular array antenna with circular polarization and high gain. The aim of this thesis is to design, optimize and implement the proposed antenna for a 5.5 - 7 GHz frequency band. The thesis deals with theoretical fundamentals in order to subsequently present the concept of the antenna. Furthermore, it describes its design and implementation stages. The antenna was designed in the full-wave program CST Microwave Studio and fabricated on dielectric substrate. Both simulated and measured property results are evaluated in the conclusion.
Radar cross section of passenger cars
Hanslík, Radovan ; Pítra, Kamil (referee) ; Raida, Zbyněk (advisor)
This diploma thesis is aimed at radar cross section of passenger cars. Basic scattering parameters of simple targets are described. Some numeric methods used for computing radar cross section are discussed. CST Microwave Studio is used for simulation of passenger car with two different solvers. For the results there are plots of radar cross section of a car for 1 GHz, 24.125 GHz and 33 GHz. There is a plot of visualized hotspots.
Antenna array to determine positions of airplanes
Zelenka, Pavel ; Pokorný, Michal (referee) ; Raida, Zbyněk (advisor)
The project is aimed to design an antenna array for an aircraft positioning system at an airport. The system operates at frequencies 1030 MHz and 1090 MHz. The antenna is also used by the DME/TACAN system operating in frequency range from 1025 MHz to 1150 MHz. The required impedance bandwidth of the antenna array is 125 MHz, i.ee from 1025 MHz to 1150 MHz. The theoretical part of the thesis analyses properties of different patch antennas and discusses the possibility of extending the impedance bandwidth. The practical part is focused on the development of the numerical model of the broadband stacked patch antennas. In addition, properties of the 3-element and 4-element antenna array are compared. At the end, results of the thesis are summarized.
Circularly polarized textile-integrated antenna array
Rujzl, Miroslav ; Láčík, Jaroslav (referee) ; Raida, Zbyněk (advisor)
This bachelor thesis deals with the design of the right-hand circularly polarized antenna arrays operated in the ISM band 5.8 GHz. The planar antenna array is integrated into the 3D textile produced by SINTEX, which is used as upholstery on the roof of a car. In the thesis, several antenna models are described. Models operate with linear and circular polarization. Initial antenna designs were based on a microstrip technology. Later antenna designs are modified using substrate integrated waveguide technology. Finally, a three-element patch array with a coaxial excitation was fabricated and tested.
Neural Modeling of Electromagnetic Fields in Cars
Kotol, Martin ; Škvor, Zbyněk (referee) ; Koudelka, Vlastimil (referee) ; Raida, Zbyněk (advisor)
Disertační práce se věnuje využití umělých neuronových sítí pro modelování elektromagnetických polí uvnitř automobilů. První část práce je zaměřena na analytický popis šíření elektromagnetických vlny interiérem pomocí Nortonovy povrchové vlny. Následující část práce se věnuje praktickému měření a ověření analytických modelů. Praktická měření byla zdrojem trénovacích a verifikačních dat pro neuronové sítě. Práce se zaměřuje na kmitočtová pásma 3 až 11 GHz a 55 až 65 GHz.
Design and realization of a passive UHF RFID liquid level sensor tag
Pařízek, Tomáš ; Polívka, Milan (referee) ; Raida, Zbyněk (advisor)
The project deals with a theoretical design of passive ultra-high frequency radio identification (UHF RFID) tag for the measurement of liquid levels. Liquid level has an influence on the input impedance of an RFID tag antenna. The changes of input impedance have been used to distinguish individual liquid levels. Furthermore, this project presents optimization methods for the highest efficiency of an UHF RFID tag in Matlab and it aims to design a suitable antenna within CST MICROWAVE STUDIO.
Multiband embroidered antennas
Fraj, Lukáš ; Olivová, Jana (referee) ; Raida, Zbyněk (advisor)
This thesis is engaged into the designing embroidered dipole multiband antenna. Numerical models of the antenna, operating at GSM 900 Mhz, PCS 1900 MHz and WLAN 2450 MHz bands, were designed using finite-element ANSYS HFSS software. Simulations of this antenna in the free space and near the human body, interpreted by numerical model, are compared with each other. Afterwards the antenna is optimized for 900 MHz, fabricated and measured. All achieved results are compared with the pattern.

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