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Frequency filters using voltage conveyors
Dohnal, Pavel ; Vrba, Kamil (referee) ; Minarčík, Martin (advisor)
The topic of this bachelor´s thesis was frequency filters and their realization using voltage conveyors. The main goal of my thesis was design and simulation of frequency filters with voltage conveyors through two different methods. At first there were found filters second order with voltage conveyors using autonomous circuits. These circuits resulted from total admitance net. Then the frequency filters using voltage conveyors were solve through synthetic components. At the beginnig of this project the frequency filters, their characteristics, realizations and types were defined. Then were designed basic properties of current conveyors, from which we can derive voltage conveyors. The voltage conveyors are basic building components of my thesis. There were defined individual types of voltage conveyors and their close specification. There was defined universal voltage conveyor. Through the universal voltage conveyor we can realize all types of voltage conveyors. After the definition of useful species there were designed the frequency filters second order using voltage conveyors with four passive components using the total admitance net. There were found 44 these circuits. Then one of these circuits was selected and this circuit was simulated to lowpass and hipass. Subsequently the other method was used, where were used the synthetic components to creation of filters secon order. The circuits resulted from autonomous circuits, which were produced by the first method. 25 of these autonomous circuits were usable for this method. One of these circuits was simulated to lowpass and hipass.
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Multifunctional analog frequency filters
Žůrek, Radomil ; Koton, Jaroslav (referee) ; Minarčík, Martin (advisor)
Main topic of this bachelor thesis are the frequency filters and their application. It presents multifunction frequency filter circuits with focus on active circuit elements like current conveyors (GCC), voltage conveyors (GVC) and transconductance amplifiers (OTA), which operate in both voltage and current modes. Then it presents the outcomes of designing 26 second order frequency filters, all operating in both voltage and current modes. It discusses in theory the problematics of M-C graph design, which is graphics-based analogy of voltage and current incidental matrices. Selected circuit designs are examined as examples with their transfer functions determined and results presented as module frequency characteristics. Individual M-C graphs (signal flow graph) are designed for each filter circuit. In conclusion are summarized the characteristics of M-C graphs and their suitable applications.
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Controlled analog frequency filters
Martinek, Pavel ; Koton, Jaroslav (referee) ; Minarčík, Martin (advisor)
In this bachelor’s thesis are described elements frequency filters, especially OTA amplifier, current and voltage conveyor. There're presented possibilities of control frequency-selection filters and components to control, analog multipliers, DA converters, controlled amplifiers and digitally controlled potentiometers. There are discussed some circuits of controlled filters and their possibilities of independent control of parameters f0, Q. Frequency characteristics for mentioned filters are verified simulator programme. The circuits are modified to other type filter and again frequency charakterestics are verified simulator programme PsPice.
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Oscillators and function generators using current and voltage conveyors
Šťastný, Lukáš ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
Conveyors are an integral part of modern devices. In this thesis, a slew of areas oscillators and function generators with current and voltage conveyors. Individual applications are categorized according involvement with conveyors and other elements. The functionality of the need for involvement in the program PSpice simulation. As a current conveyor is used OPA861, EL2082, further use of RC circuits and opto-CNY 17.
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Versatile autonomous circuit equivalents of floating and grounded passive elements
Štěpán, Radim ; Koton, Jaroslav (referee) ; Herencsár, Norbert (advisor)
This thesis deals with a proposal of versatile autonomous circuit equivalents of floating and grounded passive elements by means of modern active tectonic blocks, such as current and voltage conveyors of all three generations. Current conveyors range as essential tectonic blocks in a current mode. Concerning signal processing, it encompasses a mixed tectonic block. In most cases, these elements may be substituted for presently insufficient operating amplifiers. The voltage conveyor was defined on the basis of duality of current and voltage modes. This element could be selected as a suitable active component for circuits operating in a voltage mode. Implementing the connection, a general autonomous circuit is taken into account. By selecting given admittances, a FDNR (floating frequency dependent negative resistance) element, floating capacitance, floating inductance and ground to floating admittance converter may be implemented. The practical part describes connections which fulfill given requirements. The suggested elements are simulated in comparison with ideal elements and subsequently, they are applied to a frequency filter. The second order filter with a proposed induction coil was practically assembled and experimentally measured in a laboratory. The measured results were compared to simulations received by the use of ideal and real models of current and voltage conveyors.
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Controllable Frequency Filters with Modern Active Elements
Preclík, Milan ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
The work deals with design of transformation cells suitable for realization of higher orders frequency filters with possibility of cutoff frequency control. At first, there is a common description of frequency filters and active elements like current and voltage conveyors. Furthermore assumptions of cutoff frequency control are defined which result in a convenient characteristical equation. Phylosophy of synthetic elements DP , EP , DS , ES including a possibility of change of cutoff frequency is next in line. By exploitation of synthetic elements theory new circuit’s schemes of transformation cells are searched. The work continues with the choice of appropriate transformation cells for resulting circuit’s solutions of frequency filters with possibility of cutoff frequency control by using transfer coefficients of active elements or with help of passive elements. The work concludes with verification of its proper function based on a simulation executed in OrCAD and with practical implementation of choosen circuit’s solution.
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Nonlinear circuit structures using current and voltage conveyors
Gabriel, Viktor ; Hanák, Pavel (referee) ; Koton, Jaroslav (advisor)
This thesis deals with the use of active components in nonlinear circuits. First the variants of the current and voltage conveyors are theoretically described. Then the thesis deals with the design of the new curcuit structures with nonlinear components, which comes out from the former known realizations. Several possible solutions of the examined circuit have been designed and the most convenient structure has been selected. The chosen solution has been thoroughly analysed in subsequent diploma thesis to enable comparison of the theoretically designed circuit with the practically realized one.
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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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Universal active elements and their usage in frequency filters
Vencálek, Roman ; Kubánek, David (referee) ; Herencsár, Norbert (advisor)
This master’s thesis deals with the advanced universal modern active elements, such as the current and voltage conveyors. The problem with small bandwidth has been fixed due to the quick development in recent years. Current and voltage conveyors are still being researched. The good properties of conveyors promise their possible commercial usage in the future. For the research of current conveyors we can use parts of other integrated circuits and thus get elements with similar properties. This thesis suggests how to make an active filter using the DBTA and FDBTA elements which were created by “combination” of the universal current and voltage conveyor. Simulations were carried out on selected circuits containing the DBTA to verify their properties. It was for finding out about their behaviour in real applications that the circuits were constructed. This enabled the comparison of the results acquired from the simulation programs with the ideal behaviour of the elements and with the models simulating real properties against the values acquired by measurements of the circuits.
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Modeling of the unconventional functional blocks in Pspice
Zetík, Rostislav ; Brančík, Lubomír (referee) ; Petržela, Jiří (advisor)
This master´s thesis on theme Modeling of the unconventional functional blocks in Pspice deals with the design procedures of electronic elements models and should to help with their create. At the beginning the thesis theoretically describes how the models are created and what possibilities for modeling the program Pspice offers. There are drawn near the individual levels of model and their properties. The second main part of thesis shows practically step by step the design procedures of models of the operational amplifier, current and voltage conveyors, OTA, CDTA, immittance inverter and converter and logarithmic amplifier. There are created the models up to 4.th level, the ideal, resistive, frequency dependent and nonlinear. The basic transmission properties, input and output impedance are modeled this way. The created models with sufficient accuracy correspond to the parameters of the commercial elements. This thesis such shows the possibilities of the program for finding of values for model components like stepping or Optimizer tool.
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