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LNA for the APT signals receiver
Žúrek, Dan ; Urbanec, Tomáš (referee) ; Baran, Ondřej (advisor)
This bachelor thesis is dealing with design, realization and optimization of the LNA (Lownoise amplifier) for receiving of APT signals from the NOAA weather satellites in 137 MHz – 138 MHz frequency band. The first part of this work is aimed on critical parameters of the amplifier and the filter circuits especially on a noise figure and a high selectivity. The next part of this project is about the particular concept and simulation of LNA by using the Ansoft Designer software. The printed circuit board is realized in the Cadsoft Eagle. The final part of this bachelor thesis is dealing with a production of such amplifier together with its measurement and testing in a real operation of receiving APT signals.
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Visualization of vocal cords movement
Kutálek, Libor ; Sekora, Jiří (referee) ; Rozman, Jiří (advisor)
The aim of this work is to clarify the function of the vocal cords and get familiarized with their investigative methods. In this work we find possible solutions to the peripheral device to illuminate the rapidly vibrating vocal cords using an LED that is less energy exacting than conventional halogen lamps. Then there are solved the problems of processing, signal filtering and finding the natural frequency of vibration of the vocal cords.
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Electronically controllable frequency filters with current active elements
Suchánek, Tomáš ; Lattenberg, Ivo (referee) ; Kubánek, David (advisor)
The aim of the thesis is to study the possibilities of the electronic frequency ?lter com- posed of active elements operating in current mode. The main opportunities lie in the change control parameters, most are marginal or quality factor frequency. As the active elements are considered especially CC (Current Convejor), controllable current ampli?er DACA (Digitally Adjustable Current Ampli?er) or combination with the current tracker MO-CF (Multiple Output Current Follower). Another part will focus on the management of the above parameters using digital potentiometers and choosing the appropriate ?lter structure. The ?nal task was to digital control parameters using a PC and measuring its properties.
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Satellite Receiver with Integrated Antenna Tuner
Matoušek, Martin ; Pítra, Kamil (referee) ; Urbanec, Tomáš (advisor)
This work is focused on proposal of receiver with Integrated Antenna Tuner operating at 28 MHz. The design was primarily focused on simplicity and low power consumption. The receiver is adapted for SSB modulation. This work was realized for the transmission of audio signals. SSB modulation is far more efficient in terms of the radio spectrum used. First part of this thesis describes about the Antenna Tuner and block diagram of a receiver. Next parts are focused on proposal of individual blocks of the receiver, especially its most important parts. Finally, the overall evaluations of the design characteristics of SSB receivers with Integrated Antenna Tuner are discussed.
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Person Identification and Verification Using EEG
Žitný, Roland ; Orság, Filip (referee) ; Tinka, Jan (advisor)
The aim of this work was to create a brain-computer interface that reliably identifies and verifies a person using his electroencephalographic signals. Creating a user profile and verifying it is based on processing reactions to his own face, and the face of strangers or acquaintances. Algorithms such as bandpass and noise removal using wavelet transformation are user to filter signals. The classification of reactions is performed using a convolutional neural network or linear discriminant analysis. The average accuracy of the linear discriminant analysis is 66.2 % and of the convolutional neural network is 58.7 %. The maximum achieved accuracy was with linear discriminant analysis and at 93.7 %.
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ARC filter for frequency analyser
Janečka, Martin ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this work is to propose and realization an active frequency filter with a 4th grade bandpass for making it possible to electronically tune the resonant frequency in range of 10Hz to 100kHz and adjust bandwidth. The thesis discussed two possibilities of filter connections using cascade synthesis. To choose a better option a filter simulations were made in Pspice. Based on the simulations, the number of components and the possibility of electronic tuning a better option is selected. This circuit is implemented, measured and then compared with simulations.
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Textile electrodes in ECG measurement
Kocum, Filip ; Vélim, Jan (referee) ; Cupal, Miroslav (advisor)
This semestral thesis deals with the issue of electrocardiogram measurement and heart rate detection using textile electrodes placed on the body. One of the main tasks was to design the possibilities of attaching the sensors to the body in order to ensure the best possible adhesion to the skin. The work focuses on the design of suitable electrode placement in terms of functionality and stability of measurement. Furthermore, the work focuses on the comparison of textile and Ag / AgCl electrodes. The last point was the design of a preamplifier for measurement and its subsequent implementation.
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Detection of K-complexes in sleep EEG signals
Hlaváčová, Kristýna ; Ronzhina, Marina (referee) ; Kozumplík, Jiří (advisor)
This master’s thesis deals with issues of the detection of K-complexes in EEG sleep signals. Record from an electroencephalograph is important for non-invasive diagnosis and research of brain activity. The scanned signal is used to examine sleep phases, disturbances, states of consciousness and the effects of various substances. This work follows the automatic detection of K-complexes, because the manual labeling of graphoelements is complicated. Two approaches were used –Stockwell transform and bandpass filtration followed by TKEO operator application. All algorithms were created in the MATLAB R2014a.
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Adaptive active band - pass
Velička, Pavel ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this thesis is to find and propose solutions adaptive ARC frequency bandpass filter, where it will be possible to change the bandwidth and tuning the center frequency. Centre frequency will be tuning in the range from 10kHz to 100kHz. Bandwidth is tunable to the maximum range that will enable us to select involvement. The thesis selected two methods of implementation of the filter. It made the comparison and selection of improved variants. Thesis includes calculations of the resulting variant filter and describes how to tune the filter, and then simplify the tune selected filter. Bachelor thesis includes a complete filter design for its implementation. A suitable method of electronic tuning were selected digital potentiometers controlled programmed microcontroller. This method was also subsequently implemented.
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VHF SSB Receiver with Low Consumption
Matoušek, Martin ; Povalač, Aleš (referee) ; Urbanec, Tomáš (advisor)
This work is focused on proposal of SSB receiver operating at 30 MHz. The design was primarily focused on simplicity and low power consumption. This work was realized for the transmission of audio signals. SSB modulation is far more efficient in terms of the radio spectrum used. First part of this thesis describes a block diagram of a receiver. Next parts are focused on proposal of individual blocks of the receiver, especially its most important parts. Finally, the overall evaluations of the design characteristics of SSB receivers are discussed.
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