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Adaptive frequency filter
Kříž, Petr ; Hájek, Karel (referee) ; Sedláček, Jiří (advisor)
The aim of this work is to design a filter of the type low–pass of order 5th with Butterworth’s approximation in the range of over-tuning 10 – 100 kHz and if it will be possible so! achieve even higher marginal frequencies. To compare two typical representatives of the frequency filters cascading and non-cascading synthesis from the viewpoint the accuracy of an! approximation function, sensitivity to the tolerance values of components, number of the components (mainly OZ) and viability, especially the possibility of electronic over-tuning in selected frequency range. On the basis of these conditions will be chosen one design, which will be realized later. Further it will be necessary to consider the possibilities of electronic over-tuning and to choose for this over-tuning suitable component, to design user management changes of marginal frequency fm by the help of keyboard + LCD and control application on the PC. For this hardware will be programmed appropriate control software. At the end of this work will be constructed appropriate device, which fullfils requirements written above and will be subjected to the laboratory measurements that verify function of this device. The constructional details of the filter are presented in the enclosure at the end of this work. At the CD are available all materials, which were created during the master’s thesis or which are necessarily concerned.
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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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Frequency filters with OTA amplifiers
Naider, Jan ; Kubánek, David (referee) ; Vrba, Kamil (advisor)
Work is bent on problems frequency-selection filter with OTA amplifier. Analyses suggestions frequency-selection filter 2.order with OTA amplifier plus frequency-selection filter highers order. Smoothing - out proposal multifunction frequency-selection filter 2.order with by three OTA amplifier in suspense regime, with the support computer methods proposal plus his realization. Establishes temporary carrier function designed filter command plus malingers his temporary carrier frequency characteristics. Designed frequency-selection filter implements plus experimentally checks his characteristics. Record confront with abstractedly gained values computer malingering.
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Design of tunable frequency filters with modern current active elements
Stejný, Jiří ; Herencsár, Norbert (referee) ; Jeřábek, Jan (advisor)
This master´s thesis deals an active elements called digitally controlled current amplifier, multiple-output current follower and its usage in tunable frequency filters. These tunable frequency filters operate in a pure current mode. In the first part of this work are presented the different types of current active elements. Universal current conveyor, multiple-output current follower, digitally controlled current amplifier (UCC, MO-CF, DCCA). In the second part of this work are introduced particular methods of design tunable frequency filters. Special attention is given to using the design method of via autonomous circuits because it is one of the most. In the last part of this thesis are designed and computer-simulated individual multifunction tunable frequency filters with those already active yet elements. These filters were designed via autonomous circuits or modification of existing circuits. The functionality of the proposed filtres have been verified by computer simulation. Snap3 program was used for the symbolic analyse of circuit and OrCad PSpice program was used to simulate the characteristics of multifunction filters.
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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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Frequency Filters with Controllable Current Followers
Novotný, Matouš ; Herencsár, Norbert (referee) ; Koton, Jaroslav (advisor)
Submitted work engage in suggestion and realization of frequency-selection filters with usage one or more active devices CMI (Current Mirror and Inverter). The preamble of thesis is applied to theory of frequency-selection filters and possible usage of them. The projected circuit layouts are discussed next to would be possible change some of choice parameters of frequency-selection filter. The part of thesis is numerical suggestion of found solutions, their simulation in suitable program and realization.
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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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Frequency Filters with Current Active Elements
Jeřábek, Jan ; Ondráček,, Oldřich (referee) ; Kolka, Zdeněk (referee) ; Vrba, Kamil (advisor)
This doctoral thesis is focused mainly on research of new current active elements and their applications in frequency filters suitable for current-mode. Work is focused on design of new filtering structures suitable for traditional single-ended signal processing and also on structures suitable for fully-differential applications. The thesis contains three designed general conceptions of KHN-type second-order filters. Adjustability of quality factor and pole frequency is provided by controllable current amplifiers that are placed properly in designed structures. Structures also contain second-generation current conveyors, multiple-output current followers, transconductance amplifiers and their fully-differential equivalents. There are lot of possible solutions that could be obtained from general structures, some of them are presented in the work. The thesis also presents several multifunctional and also single-purpose filtering structures of second-order and two variants of n-th order synthetic elements which are suitable to realize higher order filters both in single ended and fully differential type. In each case, functionality of new solutions is verified by simulations and in several cases also by real measurement.
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Voltage Conveyors in Linear Blocks
Dohnal, Pavel ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
The main goal of this diploma thesis will be realization of tunable frequency filters using voltage conveyors, that are only little explored yet. At the beginnig of diploma thesis the frequency filters and their types will be defined. The theory of voltage conveyors based on principle of duality results from the character of current conveyors. Accordingly these active components will be closely presented. At first there will be defined individual types of voltage conveyors and their closer characteristics. Then design methods of frequency filters using unconventional active components will be described. There will be defined the method of the total admitance net, subsequently design using synthetic components and at the end there will be presented method using follow graphs that will be used to design concrete circuit solution. Using follow graphs method will be found circuit solutions of current structures with unconventional active components. During searching circuit solutions will be very important the posibility to operate the quality factor. That can be obtained by two ways. One way is the activ operation which is done by coeficients of the activ component. Other way is operating using the passiv component. There are found 26 circuits that realize condition of active operating using two active and four passive components. One of these circuits will be chosen and simulated in simulation program PSpice. To compare both methods of operation there will be compiled some circuit with passive operating with two active and five passive components and one of the passive components will be able to operate the quality factor. This circuit will be simulated in the simulation program PSpice again. The circuit will be real compiled and experimentaly measured in laboratory. Results of this measurement will be compared with calculated values and with values acquired from the simulations.
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