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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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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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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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Crowd Counting in Video
Kuřátko, Jiří ; Sochor, Jakub (referee) ; Herout, Adam (advisor)
This master's thesis prepared the programme which is able to follow the trajectories of the movement of people and based on this to create various statistics. In practice it is an effective marketing tool which can be used for instance for customer flow analyses, optimal evaluation of opening hours, visitor traffic analyses and for a lot of other benefits. Histograms of oriented gradients, SVM classificator and optical flow monitoring were used to solve this problem. The method of multiple hypothesis tracking was selected for the association data. The system's quality was evaluated from the video footage of the street with the large concentration of pedestrians and from the school's camera system, where the movement in the corridor was monitored and the number of people counted.
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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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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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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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