|
|
Power amplifier for 2 metres radio amateur transmitter
Klapil, Filip ; Vařacha, František (referee) ; Prokeš, Aleš (advisor)
This work deal with development a solution of a power amplifier for 2 metres radio amateur transmitter with a minimum output of 1 kW. Part of the solution is to use a commercial module of power amplifier. In addition, the design of the input attenuator, the switching elements in the signal path, the output filter and the protection circuits including cooling. The bachelor thesis contains a proposal of a system solution with a discussion of required performance and legislative requirements. This is followed by a hardware section, where the work is devoted to the design of the hardware, the theoretical calculation of the components and the simulation. In the last part of the work deals with practical implementation, verification of function and measurement of achieved parameters and their evaluation.
|
|
|
ARC filters with modern active elements
Sedláček, Petr ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this project is to compare the characteristics of low pass and high pass filters designed by various methods of synthesis. Firstly, the attributes and characteristics of filters and realisations of higher order filters using normed low pass filter and approximation of gain-magnitude frequency response are described and then used in application. The circuits that substitute coils directly or undirectly using the Bruton transform are discussed next. The practical part of project concerns of design of high pass and low pass itself, using two methods of synthesis. Proper real operational amplifier has to be choose for used frequency. In the final part of work the designed circuits were realized and their characteristics were measured and examined.
|
|
|
Active Frequency Filters for Higher Frequencies
Fröhlich, Lubomír ; Dostál, Tomáš (referee) ; Biolek, Dalibor (referee) ; Sedláček, Jiří (advisor)
This thesis deals with the synthesis and optimization of frequency analogue filters with modern active elements usable for higher frequencies. The thesis is divided into three parts, the first part deals with the problematic concerning Leap-Frog combined ARC structure. Due to a difficult design, this method is not described in a detail and used in practice, although it shows e.g. low sensitivity. Firstly, a complete analysis of individual filters was made (for and T endings) and consequently these findings were used during implementation of this method to NAF program. Finally, samples of real filters were realized (for verification of functioning and correct design). Another very interesting topic concerning filters is usage of coupled band-pass for small bandwidth, where it is necessary to solve the problems concerning ratio of building elements values, but also price, quality, size of coils, sensitivity, Q factors, coefficients etc. That is why in practice a coil is very often substituted with other equivalent lossy and lossless blocks which create ARC filters structure. The design and the possibility of usage of lossy grounded elements were described here (such as synthetic inductors, frequency dependent negative resistor). Some parts of the design are individual computer sensitivity analysis, setting of usage and quality comparison of individual lossy grounded blocks. Besides, a program for these elements was created, it is useful for a quick design and depiction of transfer characteristics. The third part deals with the usage of tuning universal filters consisting three or more operational amplifiers, which secures its universality and possibility to create different kinds of transfer characteristic. In practice, Akerberg - Mossberg and Kerwin - Huelsman - Newcomb are the most used types of filters. These were also compared with less common universal filters. In the end, the possibility of digital tuning of universal filter with the help of digital potentiometers for filters of 10th order and frequency around 1 MHz was shown.
|
|
|
Diagram Eye Imaging
Chýlek, Richard ; Kratochvíl, Tomáš (referee) ; Říčný, Václav (advisor)
The aim of this bachelor´s thesis was to design an adaptor for imaging the eye diagram of digital video signals in the basic zone. Adaptor is a device by which we can illustrate the signal distortion resulting from the passage through the transmission channel, using the XY displeying.This adaptor should be designed with the symbol timing recovery. This means that the adaptor has been divided into two parts. Part of the broadcast, which consists of a units generator timing signal, generator block and pseudorandom sequences. These blocks of me created a 127-bit sequence with different frequencies (2 MHz, 4 MHz, 8 MHz and 16 MHz). In the evaluation of the adaptor, which is composed of symbol timing recovery, frequency dividers, low pass filter and all-pass network for phase synchronization and adjustment signal amplifiers, the signal is divided into two branches. The first walked through a matching amplifier and led to vertical clamps oscilloscope. The second passes through progressively above districts and ultimately led to the horizontal clamp oscilloscope. The individual blocks were designed in detail and implementation schemes were drawn up for both of the adapter. From these themes, I then proposed a DPS for each of the adaptor. They were blocks of broadcast adaptor, evaluation of the adaptor, the blocks of resources and subpanel for two main blocks. The result of this work is complete documentation for the implementation of this adaptor. Direct implementation is not required.
|
|
|
Defected ground planar filters
Tomíček, Martin ; Vágner, Petr (referee) ; Raida, Zbyněk (advisor)
In the bachelor´s thesis, the microstrip low-pass filter with the defected ground is described. The project deals with the design and the simulation of the filter in Ansoft Designer, confrontation of results between simulation and realized low-pass filter and the discussion of obtained results.
|
|
|
Adaptive antialiasing frequency filter
Sovadina, Václav ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this project is to become acquainted with the Bessel approximation function and to present the possible connections of the adaptive antialiasing filter. Then, cascade and partition filter realizations are designed and their computer analysis are carried out. Furthermore, the thesis deals with the options of electronic realignment of filters. A common connection of digital potentiometer along with the block diagram of the whole mechanism are described. The next part presents a construction of the analogue part of the filter, measuring of its real characteristics and the control circuit for the analogue part.
|
|
| |
|
|
Intelligent lightning system
Harman, Ján ; Šír, Michal (referee) ; Bradáč, Zdeněk (advisor)
The aim of my master’s thesis is a system for control of the light intensity. It is electronic equipment which controls the intensity of the light circuits based on settings and input signals. This equipment could work on single-phase systems or multiphase systems. The equipment is controlled by the signal DMX-512 which is a standard for the control of lighting technologies. The set up of this equipment is based on a personal computer or in a limited form by a small connected display.
|
|
|
DC/AC inverter with digital control
Štaffa, Jan ; Pazdera, Ivo (referee) ; Minárik, Vladimír (advisor)
This work is focused on single phase inverters, which are used for the conversion of the direct current to the alternating current and are nowdays used especially in systems of back-up power supply. The specific aim of this work is implementation of design hight power circuit of inverter include calculation of control algorithm. It describes the complete solution of power circuit. Next step is a analysis of problems concerning the digital control with help of signal processor which is used for solution of regulator structure. Check of the design and checkout of control algorithm is made in the form of simulation in the MATLAB Simulink. Debugged program algorithm is subsequently implemented into the signal microprocessor. The work results rate estimation functionality of inverter and solution of control algorithm.
|
|
|
Active electrical filters based on switched-capacitor circuits
Třeček, Stanislav ; Dostál, Tomáš (referee) ; Brančík, Lubomír (advisor)
This thesis deals with concept of universal frequency filter by application of a switched-capacitor functional block. The concept is based on the theory of switched-capacitor circuits and the theory of a design of classical frequency filters. The printed circuit board was designed based on the filter connection developed by using a software Eagle. The filter was implemented as a laboratory product. This product has been revitalized and the frequency response of all types of filters has been measured. The measured parameters were compared with the parameters set out in the technical documentation of functional block.
|
guest ::
