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A Contribution to Optimal Synthesis of Filters
Szabó, Zoltán ; Hájek, Karel (referee) ; Král, Bohumil (referee) ; Sedláček, Jiří (advisor)
The presented dissertation thesis is focused on the optimization of filtering circuit synthesis. In the five main sections of this work, the author analyzes partial problems related to several areas within the synthesis of modern filtering circuits. The first chapter constitutes an examination of elementary aspects which characterize present-day integrated circuits in voltage feedback operational amplifiers, and this main content is further complemented with a view on possible application of these circuits for the designing of filtering circuits as proposed within subsequent parts of the thesis. In this context, the second chapter contains a description of the design and optimization of digitally controlled universal filters tunable by means of digital potentiometers originally produced for audio technology. These digitally controlled circuits are increasingly utilized as analog preprocessing blocks in digital signal processing systems. The most extensive portion of the dissertation is dedicated to a complex analysis of individual configurations of economical, purposely lossy active function blocks and modern voltage operational amplifiers. This part of the thesis aims at providing a detailed insight into the characteristics of individual configurations of examined circuits; furthermore, in this respect, the author proposes a comparison of various application possibilities relating to these circuits and their wider use in the field of active frequency filters optimization. The described section of the work also includes a definition and examples of application of the designed and realized program, which facilitates significant simplification of purposely lossy ARC filters. In the penultimate part of the dissertation thesis, the design, development, and verification of a suitable synthesis procedure are presented together with the optimization of data and (in particular) power models of EMC filters. Based on the verification of characteristics inherent with the designed models of EMC filters, the suggested measuring procedure related to these filters is described, including the design of a station for measuring elementary parameters of line anti-interference devices up to very high frequencies. In the last section of the thesis, the author discusses the procedure of air ions concentration measurement through an aspiration condenser and analyzes the systematic and random errors as well as the optimization of filtration characteristics of the applied measurement method. This part includes the description of the design and characteristics of the realized fully automated measurement system with an aspiration condenser.
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Design, simulation and measurement of active filters with modern functional blocks
Melša, Vojtěch ; Petržela, Jiří (referee) ; Brančík, Lubomír (advisor)
This work concentrates on the possibilities of how to connect electric filters with functional blocks. Then we choose the best possible connections and their characteristics are simulated in the Pspice program. From the comparison of the results of simulation, possibilities of tuning, quantity of functions, complicacy of connections and mainly by commercially available integrated circuits is chosen the connection which is realized in a laboratory preparation form. Its measured characteristics are compared with results of simulation
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Modem -repeater for narrow band technology of PLC
Novák, Michal ; Mlýnek, Petr (referee) ; Mišurec, Jiří (advisor)
This semestral thesis focuses on the circuit design of the repeater for PLC communication in order to achieve greater distance in communication. It can also serve as a bridge for a separate modem device power grid. In this work we discuss the involvement of individual assembly parts repeater and proposed method of connection.
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Application possibilities of LNVGA programmable amplifier
Sobotka, Josef ; Hanák, Pavel (referee) ; Jeřábek, Jan (advisor)
This thesis deals with the theoretical description of the qualitative characteristics and parameters of some modern active elements, also discusses the theory of signal flow graphs at the level applicable for the following frequency filter design methods. The thesis is also generally discussed the issue with the circuit simulator PSpice modeling theory and voltage amplifiers on the basic 6-levels. The practical part of the work is divided into two parts. The first practical part is dedicated to design four levels of simulation model of components LNVGA element. The second practical part contains detailed theoretical proposals for three circuit structures implementing the frequency filters 2nd order (based on the basic structure of the OTA-C) using signal flow graphs with configuration options of Q and fm based on the parameters of active elements in the peripheral structure and their verification with prepared LNVGA model layers.
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ECG monitor in LabVIEW
Pavlišta, Libor ; Kolář, Radim (referee) ; Harabiš, Vratislav (advisor)
The main purpose of this work is to get know about ECG signal, its genesis and relationship between mechanical and electrical part of the heart. Furthermore about the detailed disassembly of parts, for example of QRS complex, the determination of faulty statuses, the calculation of heartbeat frequence. We will take a look into the patient's monitors. We will get know about the measuring of ECG signal and how to treat the input signal to eliminate the undesirable components of signal, for example unwanted network noise - so-called network brum. We will study the concept of simple monitoring system with th draft of necessary filter in LabView program. We will construct alarms for some cardiac abnormalities, such as premature heart contractions. We will calculate heart rate. We will retrieve of data from an external source and we will prepare the appropriate graphical user interface.
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Modern active elements and their behavior in linear circuit blocks
Kosztyu, Tomáš ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
The topic of this master’s thesis was a frequency filters and their realization using modern active elements like UVC, UCC, VFA, CFA and OTA. The base point of this thesis was designed frequency filters with these active elements, when the shape of the transfer function will be identical for all structures and compare the characteristics of active elements. The proposed frequency filters are second order with one or two active elements. In the first part of thesis are discussed basic properties of frequency filters, their properties and distribution. Next are described the general characteristics of active filters and their basic elements such as operational amplifier OTA, VFA and CFA, and recently more frequently used voltage and current conveyor. The second part is the frequency filters designed with these elements is the same transfer function. Subsequently, simulations are done all the filters and obtained the frequency response. Finally, these filters are experimentally made and made practical measurements.
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The heartbeat counter
Malínský, Zdeněk ; Dlouhý, Jiří (referee) ; Švrček, Martin (advisor)
Heart rate variability belongs to basic and most frequently interpretation of physiologic statement in medicine. The pulse rate serves as an indicator of the heart activity. The subject of this diploma thesis is projection of the heartbeat counter. The work describes electrocardiograph and separated waves, ways of calculation heart rate, characteristics mechanism for measuring and other necessary information about heart rate measuring. This master thesis fixates on heart rate-calculation from including R-R intervals. Here is described whole project of heartbeat counter, properties of separated blocks and calculation of useful parameters. Further there is noted software resolution for the microcontroller and program for the calculation of heart rate frequency including unwinding signal preprocessing and detection of separated QRS complexes. The products of this diploma thesis are the circuit including the board circuit and codes of separated programs.
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