|
|
Antenna for receiving of DVB-T signal
Šmarda, Marek ; Lukeš, Zbyněk (referee) ; Pokorný, Michal (advisor)
The content of this work is to study selected antenna systems suitable for receiving of DVB – T. The various antenna systems will be simulated in the program for the simulation of electromagnetic field (e.g, CST Studio) and the simulation results will be commented (e.g. graphs and diagrams of radiation). Selected antenna system will be made and experimentally measured.
|
|
|
Evaluation of the Financial Situation of a Company and Proposals for its Improvement
Plottová, Sylvia ; Pokorný, Michal (referee) ; Zinecker, Marek (advisor)
The aim of this thesis is to asses the financial situation of a company based on the results of financial analysis and to present proposals for improvements in problem areas. The thesis is divided into three parts. In the first part were collected theoretical knowledge and procedures necessary to understand the nature of financial analysis. The second part applies the theoretical knowledge and assess the situation in the given company. In the third part of the work are then presented recommendations for improvement of a problematic areas.
|
|
|
Textil Integrated Horn Antenna
Jaroš, Ondřej ; Pokorný, Michal (referee) ; Vélim, Jan (advisor)
This diploma thesis describes the corrugated substrate integrated horn antenna designed to surface wave’s excitation in the UWB band groups 3, 4, 5 and 6 (6 – 10 GHz). The antenna is integrated into 3,4 mm thick textile with relative permittivity r = 1,195. The coaxial cable is connected via the SMA connector that is attached to the aluminum bracket. From the microstrip line transition the corrugated substrate integrated waveguide is excited. Two strip lines are placed in front of the aperture for improvement of the impedance matching. The directivity of the antenna is 12 dBi at 8 GHz. At the same frequency, the antenna efficiency is 70%.
|
|
|
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.
|
|
|
User influence on miniature antennas in mobile applications
Vehovský, Radek ; Polívka,, Milan (referee) ; Pokorný, Michal (advisor)
This master’s thesis deals with user influence on miniature antennas in mobile application. Electrically small antennas including fundamental performance properties and limitations are introduced in the theoretical section of this thesis. This section also deals with microstrip antennas and their common types. The accent is on PIFA antennas, their typical constructions and methods of miniaturization. In the practical section, dual-band PIFA antenna for operation at frequencies of systems GSM900 and GSM1800 is designed with the assistance of electromagnetic field simulator CST Microwave Studio. On this type of antenna, the user influence on impedance matching and radiation pattern in data mode (the user is typing message or browsing with the phone) is investigated. For this purpose the hand phantom, corresponding to author’s right hand, was made from agar based material. For typical position of human hand is designed matching network, which eliminate the user influence and ensure correct function of antenna.
|
|
|
Automotive antenna for mobile communications
Porč, Jan ; Láčík, Jaroslav (referee) ; Pokorný, Michal (advisor)
This thesis deals with design of flush–mounted planar disc antenna suitable for use in vehicles. For each of the bands GSM900 and GSM1800, which are used in Czech republic, an independent antenna has been created. As a simulator of the electromagnetic field the program IE3D has been used. For the improvement of theoretical results an optimisation in the program MATLAB has been developed. As the optimisation method the genetic algorithms have been selected.
|
|
|
EMC antenna
Tenora, Jan ; Pokorný, Michal (referee) ; Láčík, Jaroslav (advisor)
The goal of this master’s thesis was to design antenna working in frequency range from 30 MHz to 1 GHz. Designed biconical antenna requires balanced feed to work properly, therefore designing the balancing unit based on discrete components was necessary. Designed antenna was also constructed and its return loss, gain and radiation patterns were verified by measurement. This master’s thesis also introduces readers into principles of antenna measurements of disturbing signals in the area of EMC and compares different types of antennas for bands of meter and decimeter waves.
|
|
|
Virtual serial port and its safety conversion to Ethernet
Pokorný, Michal ; Krajsa, Ondřej (referee) ; Koutný, Martin (advisor)
Bachelor´s thesis try to find a solution to make virtual serial port and its safe transfer on Ethernet. Nowdays communications channels don't offer appropriate security of a whole communication. Therefore it depends on get-togethers, in order to realize this security themselves.This means ensure reliable data transfer, these data from among get-togethers encrypt in order to appropriate attacher be unable to read them in real - time, eventually to change them. As a result this Bachelor thesis is the application, which, except transfer between virtual serial port and Ethernet, insure authentication among get - togehthers communication and cipher transfer among them. As an encryption algorithm is used algorithm AES. It is concerned symmetrical cipher, which ciphers data after pages about size 128 byte.
|
|
|
Semiconductor diode modelling
Pacholík, Vladimír ; Wilfert, Otakar (referee) ; Pokorný, Michal (advisor)
This project is about phenomena, which proceed in semiconductor, eventually on semiconductor junction, including equations and relatives necessary for modeling simply semiconductor PN diode, Gunn diode and Schottky diode. Further including short way, how to use this equations and how simulate this diode in COMSOL Multiphysics and Tiber CAD software. Products of modeling are data in charts form. This charts giving basic idea about charge carriers, electrostatic potential and I-V characteristic.
|
|
|
Magnetic drive
Aubrecht, Ondřej ; Pokorný, Michal (referee) ; Raida, Zbyněk (advisor)
In the bachelor thesis, selected types of magnetic motors are analyzed and mutually compared. For each motor, a short description is given and critical evaluation of its properties is provided. In the next part of the project, all the magnetic motors are mutually compared and a suitable type of the motor for the computer simulation is chosen. The simulations are performed in programs COMSOL Multiphysics and program Femm. In the last part of the project, simulations are checked on the real prototype of magnetic motor.
|
guest ::
RSS feed.