|
| |
|
|
Special application of VoIP
Lembard, Tomáš ; Šebesta, Jan (referee) ; Fuchs, Michal (advisor)
The aim of this master's thesis is suggestion and following realization of voice transmission over the local network equipment and a description of used circuits and solutions in terms of hardware and software. This thesis deals with digitization of low-frequency signals, the structure of IP and UDP protocols, implementation of TCP/IP stack cIPS
|
|
|
Automatic antenna analyser
Dufek, Ivo ; Šebesta, Jan (referee) ; Lukeš, Zbyněk (advisor)
This project is dealing with methods of measuring impedances of the antenna systems in the frequency range from the low frequencies to the very high frequencies. There is a discussion about different methods of measuring impedance and each technique is critically evaluated. In terms of this project is compared few types of the professional antenna analyzers. According to this comparison there was made the concept of my own antenna analyzer. There is a detailed description of the design of this device’s important parts including software equipment. Designed instrument has been built and tested.
|
|
|
Electrically short multiband antenna for radioamateur use
Müller, Marek ; Šebesta, Jan (referee) ; Lukeš, Zbyněk (advisor)
The purpose of this work is identification with theory of EH antennas, do the simulation of one choice of model of EH antenna from literature and this model optimise on required frequency 14 MHz through the use of computer software CST Microwave Studio. The practical part of work is to produce choice model of EH antenna, to mete his properties and to verify use in real traffic. The EH antenna is an electromagnetic electrically short antenna, which can work as a transmitting or receiving antenna. The main characteristic of EH antenna is distributed radiating electromagnetic field, whose electric component E and magnetic component H are mutually crossed and orthogonal. The advantage of EH antennas is, that they have much smaller size on frequencies in order of magnitude MHz in comparison with conventional antennas (e.g. half-wave dipole). Their disavantages are their more complicated construction and tuning of the antenna, which must be made again, when the position of antenna is changed. Therefore the EH antenna is not so suitable for mobile application.
|
|
|
FSK modem with AX.25 protocol
Vojtek, Michal ; Šebesta, Jan (referee) ; Fuchs, Michal (advisor)
The purpose of this thesis is to design FSK modem for Packet communication. In accordance with accessible literature was constructed functioning circuit schema and subsequently there was constructed a motherboard which is mainly assembled from SMD technology. It makes this modem mobile and very easy usable in terrain. Modem communicates with PC via USB bus. Also this bus is used as power source for this device. Communication between modem and PC is realized by KISS protocol and connection with tranciever is realized by AX.25 protocol.
|
|
|
Customer Satisfaction and Proposals for its Improvement
Šimková, Anežka ; Šebesta, Jan (referee) ; Schüller, David (advisor)
This bachelor’s thesis is focused on analysing the customer satisfaction level of selected store retail chain Lidl Czech republic. The recommendations are designed to increase the level of customers satisfaction based on the results of the analysis of the marketing environment and results of customer satisfaction survey. Proposal were processed in verbal and graphical form. The proposed solutions are based on the concept of Triple Constraint.
|
|
|
Dual-band directional antenna for receiving DVB-T signal
Matyáš, Petr ; Šebesta, Jan (referee) ; Lukeš, Zbyněk (advisor)
The main goal of the masters project is to design a dual band antenna for receiving DVB-T signal in the area of the city of Brno. The antenna will be designed and detaily adjusted for receiving multiplex 1 and 3, exactly for frequencies of 538 MHz and 778 MHz. The designed antenna will be deeply tested in 4nec2 and CST Microwave Studio programs.
|
|
|
Power amplifier for shortwave bands with intelligent measurment of power
Zatloukal, Petr ; Šebesta, Jan (referee) ; Lukeš, Zbyněk (advisor)
The target of this master’s thesis is to design a functional sample of radiofrequency power amplifier for short waves radio amateur bands and measure its basic parameters such as required input power, output power, output spectrum purity and efficiency. The construction is based on results of behavioral simulation of the amplifier’s model obtained from circuit simulator cadence™OrCAD 16. The amplifier ought to be later used as an output stage for a small radio amateur transceiver.
|
|
|
DRM signal transmitter
Paták, Pavel ; Šebesta, Jan (referee) ; Lukeš, Zbyněk (advisor)
Master’s thesis deals with design and practical realisation of electronic circuits, which are needed for assembling of DRM signal transmitter for ham short waves bands. There is presented DRM standard as well as there are described the differencies between DRM for radio broadcast and for ham using. There is described design of input audio circuits, modulator, mixer, local generator, amplifier and filters. Principle of used SSB modulator is based on phase method, often called Tayloe modulator. This principle is analysed in detail including mathematical description, which was derived. It is possible to control the transmitter by program running at computer, communication takes place via USB. There is described establishment of communication in this work too.
|
|
|
TV Distribution Network Signal Analyzer
Matyáš, Pavel ; Šebesta, Jan (referee) ; Povalač, Aleš (advisor)
Aim of this project is development of the analyser for cable distributed television signals. At the beginning is a block diagram of the suggested analyser with digitally controled wideband tuner, logarithmic detector, microcontroller and a graphical display module. For each block there is a theoretical analysis, features description and description of the electronic components that were used. In the next part of this project is introduced the design of circuit schematic and printed circuit board of prototyping kit, that was used for experiments and testing of its features and parametres. Last part of this thesis focuses on finishing of a prototyping kit, development of firmware and experimental verification of the prototype's parameters.
|
guest ::
RSS feed.