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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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Fully-differential fractional frequency filters
Zapletal, Miroslav ; Dvořák, Jan (referee) ; Langhammer, Lukáš (advisor)
This diploma thesis is concentrated to fully differential and non-differential fractional-order filters with active elements. It describes how we can obtain fractional-order fully-differential filters design from non-differential design, thesis describes realization in OrCad program and simulation of this project. The first part of the thesis concerns theoretical analysis of frequency filters, active elements and fractional-order filters. The second part of the thesis includes designs of filters and simulations of differential structures and rest of non-differential structures simulation. The following part of the thesis concerns practical realization and experimental measurment of differential fractional-order filter. In the last part of this project, thesis evaluates all results which were revealed in our simulations and experimental measurment.
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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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Fully-differential frequency filters with controllable active elements
Zapletal, Miroslav ; Polák, Josef (referee) ; Langhammer, Lukáš (advisor)
This bachelor thesis deals with the fully-differential frequency filters that work in current-mode and the tunability is made possible by active elements. In the first part we will deal with theoretical analysis of frequency filters, and a closer approximation of a filter design method. The second part deals with designing of frequency filters using signal-flow graphs method, converting not differential structures to differential structures and comparing the results of proposed filters. In the third part will be made up our suggested filter. It will be also measured out in VUT laboratory to verifying his functionality. Last we will compare results of real detect values of differential and not differential connection. The last part is the conclusion, in which an assessment of the whole work is made.
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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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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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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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Fractional-order filter structures
Lefler, Filip ; Langhammer, Lukáš (referee) ; Dvořák, Jan (advisor)
Semestral thesis deals with fractional-order frequency filters. There is descripe proposal of the filter, their simulations and practical realizations. The first part is focused at the introduction to a frequency filters. The following is chapter which explore various proposals fractional-order frequency filters. The next chapter describes used activ elements in this thesis. Then there is briefly described a method of the signal flow graphs. The following is a description of the theoretical design of lowpass and highpass frequency filter, where order of the filter is between the first and second. Another part deal with the design and simulation of the four circuits. There are two curcuits consists of transconductance amplifiers (BOTA) and two curcuist consists of current followers. The last part of the thesis deals with practical realization of the two fractional-order filters.
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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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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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