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Program for design of CATV
Sedláček, Jan ; Hála, Ondřej (referee) ; Říčný, Václav (advisor)
The main task of this master’s thesis is to create an interactive computer programme for the design of small and medium television cable circuits. The first part of this document describes main conceptions of a modification and a distribution of television signals. There are also introduced basic topologies of small and medium sized distribution networks, some passive and active elements in the circuit including their usage. There is also described an algorithm for calculation of circuit’s values. The second part contains a detailed description of created programme with all of its functions. A part of this document is made by a sample calculation of the four variants of circuit and its comparison with computer calculation. In suplement are included selected parts of source code.
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BER Meter for Video Signals
Šimoník, Petr ; Frýza, Tomáš (referee) ; Říčný, Václav (advisor)
The diplomma thesis is dealing with possibilities of Signal to noise ratio measurement by method, which is based on direct measurement. It is chosen the most suitable method – signal and noise separation to two different parallel signal branches, where is measured signal strength in one branch and root mean square value in the other. The thesis is consisted of a concept of detail block scheme of Signal to noise ratio meter, which was designed in terms of theoretical knowledge. Particular functional blocks were circuit-designed, the active and passive parts were chosen and their function were described. There were made simulation and displayed input and output time flows. There is designed the whole connection of engineered Signal to noise ratio meter in the last part of my thesis. The double-sided board of printed circuit is contained too. It was created simple programme for supervisor micro-processor. Thereby were constructed complete bases for realization.
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Measurement of image CCD sensors parameters
Pavelka, Adam ; Slanina, Martin (referee) ; Říčný, Václav (advisor)
The Bachelor’s thesis deals with image CCD sensors. These transform the light radiation falling on the photosite array into the picture signal. The project describes the principals of their work and introduces the basic parameters of the sensors. The project further deals with questionability of basic parameters measurement and possibility to define equivalent parameters measurable in the laboratory conditions. Following characteristics are listed to every parameter theoretical values or values presented by the producers, conditions influencing the measurement, methodology of measurement in the laboratory conditions, list of used measuring tools, evaluation of the measured values and estimated rate of relevancy towards the theoretical preconditions.
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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.
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Automatic measurement of the motor vehicles distance.
Juřica, Lukáš ; Chmelař, Milan (referee) ; Říčný, Václav (advisor)
This work deals with evaluation of equipment used for non-contact measurement of distance between vehicles. First are discussed various principles of measuring and after the selection of the most appropriate solution is proposed a detailed block diagram of modulation, demodulation and evaluation of the whole system and its mathematical description. Another part is devoted to describing the activities of the microprocessor controller, with which is controlled evaluation part and to the control program. It also analyzes the maximal attainable accuracy of measurement and the errors that affect it. The last part includes a circuit design and simulation of selected functional block, which is a coincidence /quadrature/ detector and construction documents for evaluation and demodulation part of the measurement instrument.
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External pulse generator for neuromodulation
Flídr, Lukáš ; Říčný, Václav (referee) ; Chmelař, Milan (advisor)
This thesis deals with the treatment of chronic pain by using neuromodulation, where a external generator is used in a trial period. In the first section the principle of pain management is described and then the main nature of neuromodulation. The possibilities of chronic pain suppression are described, where we are mainly dealing with neurostimulation (stimulation with electric current). For better understanding, examples of neurostimulation usage are shown, where and in what problems it is used. Because this work deals with an external generator for a trial period (a trial system), the possibilities of testing electric impulses are described, which are then used in a implantable generator IPG. The requirements for such a external generator are also described, which are important for the design of such a device. The design of the device is firstly modeled by a block scheme, where function of the separate blocks is described and afterwards, the entire design of the external generator for neuromodulation is given. The test sample of the external generator is manufactured and tested.
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Broadband Amplifier for the Counter
Kudlička, Miroslav ; Frýza, Tomáš (referee) ; Říčný, Václav (advisor)
This work deals with possibilities design of broadband amplifier fit for the counter LCK-1. There are described three methods for possibilities solvings. The method by discretes of parts with stagger-tuned circuits, the method by operational amplifier THS3201 and the method by monolitic amplifier ERA-3. The Method by operational amplifier THS3201 is chosen like the best method, because this operational amplifier can amplify very small signals. There is designed of amplifier THS3201 in the simulation software PSpice and this results are take into account for realization broadband amplifier.
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Adaptor for the Group Delay Measuring
Müller, Marek ; Kratochvíl, Tomáš (referee) ; Říčný, Václav (advisor)
The purpose of this work is to propose the adaptor for the group delay measuring. This equipment would be worked as one special device, which it connects between wobble generator (for example wobbler X1-50) and measured circuit. This configuration can be measured not only the dependence of group delay on frequency at the measured circuit, but it can be measured even its amplitude - frequency characteristics. Whatever oscilloscope can be used for displaying of measured characteristics in the event of the application of other separate wobble generator, when the oscilloscope works in XY mode. The utilization of the equipment can be for example for the group delay measuring of intermediate frequency amplifiers by TV sets at frequency band since 30 MHz to 50 MHz. This equipment is able to measure the group delay time within the range since 0.56 ns to 2 s.
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Correctors of video signals aperture distortion
Baletka, Tomáš ; Kratochvíl, Tomáš (referee) ; Říčný, Václav (advisor)
The aim of this Bachelor thesis was first to explore capabilities of aperture correction in the analogue and digital field. Aperture correction reduces the duration of entering egde of the brightness signal of the full television signal. By dint of the theoretical findings to project a circuit diagram of the derivation and cosine aperture equalizer. The derivation aperture equalizer uses the second derivation to adjust and reduce the duration of the entering edge. The cosine aperture equalizer uses the dead time element for reduction of the entering edge of the input signal. Afterwards with the simulations to validate their functions of the adjustment of the entering edge of the input signal. In the end to compile the structural background for the creation of both of the equalizers.
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Simulation of the DVB-T digital modulation in Matlab
Málek, Pavel ; Říčný, Václav (referee) ; Kratochvíl, Tomáš (advisor)
Digital Video Broadcasting (standard DVB) is a system for transmission of the television signals in the digital form. There are used a various types of modulations in this system as QPSK modulation is used in the systems of satellite video broadcasting DVB-S (Satellite) and M-QAM modulations in the cable transmitting DVB-C (Cable). This paper mainly deals with system of the terrestrial digital video broadcasting DVB-T (Terrestrial), where OFDM modulation is used. This type of signal processing is more resistant to the distortions caused by multipath transmitting, which is main problem in the DVB-T. Matlab application, which can simulate digital modulation and demodulation of the transmission signals in the DVB-T, is created in this thesis. The models of the transmission channel is inserted between structures of modulator and demodulator. The user of this application can set the parameters of the broadcasting (e.g. constellation, OFDM mode, guard interval insertion) and the type of distortions (additive noise, reflected and delayed signals). By calculation of the channel bit error rate (BER) user can study influences of broadcasting parameters to the quality of transmission.
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