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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 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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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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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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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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Application possibilities of controllable current amplifier
Bradáč, Josef ; Koton, Jaroslav (referee) ; Jeřábek, Jan (advisor)
This thesis deals with the application using digitally controlled current amplifiers DACA (Digitally Adjustable Current Amplifer), which was developed at the Department of Telecommunications FEEC in cooperation with ON Semiconductor in 2010. In introduction is decribed the topic of active filters and oscillators. Farther active current components, besides DACA are described current conveyor UCC (Universal Current Conveyor), current amplifier DO-CF (Dual-Output Current Follower), MO-CF (Multiple-Output Current Follower) and FD-CF (Fully Diferential Current Follower) and operational transconductant amplifier BOTA (Balanced-Output Operational Transconductance Amplifer) and MOTA (Multiple-Output Operational Transconductance Amplifier). The following is a compilation of theories circuits using signal flow graphs, which are designed using a simulated filter circuits to control the cutoff frequency or the quality factor. Then design and simulation with auxiliary oscillator circuit AGC for controlling the oscillation frequency. Simulations are conducted with ideal models and with models that include some real properties. The conclusion of this work is devoted to the printed circuit board design for a selected filter circuit realization and 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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Filtering structures containing a fractional-order elements
Kubát, Pavel ; Kubánek, David (referee) ; Dvořák, Jan (advisor)
Bachelor work deals with fractal order frequency filters. The first part describes basic division frequency filters, the following part describes fractional order frequency filters and design of the circuit with fractal order. The following part contains active elements that are used for the design of the frequency filters. The last theoretical part shows design method for frequency filters, where signal flow graph is shown. Realisation, simulation and measurement are described in the practital parts.
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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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Filtering structures containing a fractional-order elements
Kubát, Pavel ; Kubánek, David (referee) ; Dvořák, Jan (advisor)
Bachelor work deals with fractal order frequency filters. The first part describes basic division frequency filters, the following part describes fractional order frequency filters and design of the circuit with fractal order. The following part contains active elements that are used for the design of the frequency filters. The last theoretical part shows design method for frequency filters, where signal flow graph is shown. Realisation, simulation and measurement are described in the practital parts.
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