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Design of a New Filter Structure Employing Devices of Fractal Order
Detko, Adam ; Kubánek, David (referee) ; Bečková, Zuzana (advisor)
This thesis deals with fractional order analogue filtration structures. The first part focuses on theory of analog frequency filters, including fractal order. In the next part, some of the active elements that can be used in frequency filters designing are mentioned. In the third part, known integer order filtration structure working in current mode is shown, which is modified to fractal in the next part. Modification to fractional order filter is realized by the RC structure Foster I, which approximates fractal order element, also known as pseudocapacitor. This part also contains calculations. Next part contains simulation results, that have been made with ideal models of active elements. The fifth part deals with the design of original filtration structure and its subsequent modification to fractal order filtration structure. Last part contains results of simulations and their comparison with the theory and for low pass as well comparison with physically measured values.
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Controlling of programmable analogue circuit
Sobotka, Josef ; Hanák, Pavel (referee) ; Vrba, Kamil (advisor)
This work deals with the design of the control software for the programmable analog circuit adjustable by means of a computer via the serial interface for the computer, as well as for programming the microcontroller. In addition, analyses the internal structure of programmable analog circuit on which it is proposed to further control, design of printed circuit boards for final programming and test equipment and measurement of the basic parameters of the circuit (transmission and phase frequency characteristics of parts and units).
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Active Filters and their Transformation to Differential Structures
Bečková, Zuzana ; Herencsár, Norbert (referee) ; Vrba, Kamil (advisor)
Bachelor thesis is considered with transformation of single--ended frequency filters to fully--differential structures. Theoretical part contains a brief introduction to frequency filters and short summary of important features of signal flow graphs. Active elements, which are used in designed filters, are shown in the third chapter. Practical part of the thesis shows five single-ended filters (one already published, four newly designed) and their transformation to fully-differential structures. Results of simulations in programms OrCAD and SNAP are shown.
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Analysis of differential and non-differential filtering structures with adjustable current amplifier
Dvořák, Jan ; Vrba, Kamil (referee) ; Jeřábek, Jan (advisor)
The master thesis deals with designs of the single-ended and the fully-differential secondorder frequency filters with adjustable parameters. This filters operate in the current mode where main element is the current amplifier DACA (Digitally Adjustable Current Amplifier). The first part describes basic behaviour of frequency filters and distribution according to filter funcion, used parts and structure. The second part of thesis describes the design of the frequency filters by the M-C signal-flow graphs and the transformating single-ended structures to the fully-differential forms. The next part deals with properties of the active elements and their simulation models. The following part describe six circuits of the frequency filters with adjustable parameters and their simulations. Four simulation models with different properties were used for simulating of the DACA in the each circuits. The last part deals with the practical design and measurement of the selected frequency filters.
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Fully-differential frequency filter designing with current active elements using signal-flow graphs method
Štork, Petr ; Jeřábek, Jan (referee) ; Langhammer, Lukáš (advisor)
This master’s thesis deals with designing of fully-differential current-mode frequency filters using signal-flow graphs method. The first part is focused on a general description of frequency filters, its function and division. Active elements that create these frequency filters, such as multi-output current follower (MO-CF), balanced or multi-output transconductance amplifier (BOTA, MOTA) and digitally adjustace current amplifier (DACA) are described in the following part. Next, problems and various techniques of designing such filters are discussed on a theoretic basis. In the remaining part of the thesis there are six circuits of frequency filters described in detail; these connections are then transferred of passive elements to a proposed connections, with the assistance of a so-called reflection. Calculations of passive form are stated, as well as results of simulations, where nondifferential and differential variations of these designed frequency filters are compared. Finaly, it has been selected some variants of designs, which has been manufactured, then measured out and resulet has been compare between each other.
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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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Analysis of filter structures with controllable amplifiers
Pánek, David ; Langhammer, Lukáš (referee) ; Polák, Josef (advisor)
This bachelor thesis is focused on simulations and practical realizations of already existing frequency filters with modern active components in current mode. New simulation ABM model (Analog Behavioral Model) of DACA (Digital Adjustable Current Amplifier) element was used in the simulations. The first part informs about problems concerning analogue frequency filters. The second part deals with used active components - DACA (Digital Adjustable Current Amplifier), MO-CF (Multiple Output Current Follower), BOTA (Balanced transconductance amplifier) and UCC (universal current conveyor). Four circuits have been chosen and implemented into PCB (printed circuit board) on the basis of simulation results. The first circuit tunes the quality factor with help of DACA component. The second circuit tunes the natural frequency and quality factor with help of DACA components. The third and the fourth circuits are simulated and implemented in differential and also in single ended forms. These circuits tune the natural frequency with help of the same set of current amplification by DACA components. The last part is summary of simulation’s and practical measurement‘s result of this project.
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Analogue emulators of fractional-order circuits
Kubát, Pavel ; Langhammer, Lukáš (referee) ; Dvořák, Jan (advisor)
Diploma thesis deals with circuits contain fractional-order elements. The first part of this paper deals with this problem, there were also described methods of design fractionalorder elements and types of circuits containing the fractiona-order elements which can be applied in practice. Used active elements for practical part can be found in the second chapter. Design of GIC circuits and implementation of fractional-order element inside the circuit are shown in the last chapture. Parasitic analysis and stability of frequency filter containing fractional-order element had been also described.
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Design of electronically reconfigurable filtering structures with modern active elements
Prát, Marek ; Kubánek, David (referee) ; Langhammer, Lukáš (advisor)
The aim of master's thesis was design of electronically reconfigurable filters. Adjustability of pole frequency or quality factor is possible. First part of thesis deals with theoretical analysis of filters, their operation modes, design of frequency filters using Signal-Flow graph method and parasitic analysis. The next part describes active elements used in thesis. In a third part, three reconfigurable filters are described and designed and their simulations and parasitic analysis are made. Last part deals with filter design in EAGLE and experimental measurement.
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Current amplifier applications in differential frequency filters
Bokůvka, Tomáš ; Kubánek, David (referee) ; Jeřábek, Jan (advisor)
Bachelors’s thesis focuses on selection and analysis of suitable filtering structures working in current mode. In the first part, there is a common description of frequency filters in terms of function and division. The following text discusses the issues of active elements that creates basic construction of these filtering structures. Core of each circuit is formed by digitally adjustable current amplifier DACA, which enables change of amplification. Another used active elements are universal curret conveyor UCC, dual-output current follower DO-CF, multi-output current follower MO-CF, operational transconductance amplifier OTA and balanced-output transconductance amplifier BOTA. In the last part, there are described four chosen applications of frequency filters. There are introduced calculations of passive components a results of simulations. For experimental confirmation there are chosen two fully-differential structures. The end of work contains summary of measurements of these two frequency filters
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