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Design and analysis of electronically reconfigurable filtering structures
Kříčka, Tomáš ; Dvořák, Jan (referee) ; Langhammer, Lukáš (advisor)
This bachelor thesis deals with the proposal of analog filters with the ability of the electronic reconfiguration. The main aim was to propose three fully electronically reconfigurable filters using different methods. The work focuses on the use of modern active elements that ensure the electronic reconfiguration. Specifically on operational transconductivity amplifiers, second-generation current conveyors and current amplifiers. The transfer functions are simulated in the Orcad PSpice software, at the ideal and behavioral level. Sensitivity and parasitic analysis is applied to the two proposed filtration structures. Both structures are made on printed circuit boards, which are measured and then their transfer functions are compared with the simulated functions.
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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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All-pass filters based on modern functional blocks
Horák, Ondřej ; Petržela, Jiří (referee) ; Dostál, Tomáš (advisor)
The present thesis is focused on all pass filters. The principle of all pass filters, their properties, the design of nth degree of these circuits will be analysed in succession and then some of functional blocks, by which these structures can be made, will be described. After that, the allpass filters will be designed and simulated in program OrCAD PSpice. First of all, the analysis will be performed with ideal components, then with real components. After that, the sensitivity and tolerance analysis will be made and the influence of parasite effects on circuit parameters will be examined. Once the experiments are finished, the design of Printed Circuit Board's (PCB) will be realized. Circuit showing the best parameters will be chosen for the design.
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Analysis of methods of measurement of fully-differential frequency filters
Kučera, Tomáš ; Kubánek, David (referee) ; Jeřábek, Jan (advisor)
This bachelor thesis focuses on measurements methods of differential frequency -selection filters with active elements in current mode. Firstly it describes differential frequency-selection filters in current mode and conversions from voltage to current mode. Next the thesis deals with measuring of particular voltage converters to differential current and back from differential current to voltage, which is an integral part for measurements of differential frequency-selection filters in current mode. For design of particular converters there was used program OrCAD there and subsequent simulation was executed in program PSpice.
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Design of new active filters, using signal flow graphs
Jašek, František ; Kubánek, David (referee) ; Vrba, Kamil (advisor)
This master’s thesis describes the design of the frequency filters by the help of the graph of the signal flows. There are defined by modern components like GVC (Generalized Voltage Conveyor), GCC (Generalized Current Conveyor), CF (Current Follower), DO-CF (Dual-Output Current Follower), OTA (Operational Transconductance Amplifier), BOTA (Ballanced Operational Transconductance Amplifier) and CFTA (Current Follower Transconductance Amplifier), the graphs of the signal flows, which describe their activity in the thesis. In the other part of the thesis is illustrated the procedure of the design of the frequency filters by the help of the graphs of the signal flows. For the concrete design was selected in the first case as the active component double output current follower and in the second case the CFTA. There are noted all designed circuits of the frequency filters also their characteristic equations in this thesis. The activity of the selected circuits was remitted to the analysis in the simulation program called PSpice. Because the active components, with which was engaged in the design of the filter which doesn’t exist in the real form, that is why the UCC, which is sufficing for attestation of the function of the circuit, was used for the simulation. The simulation was implemented in the frequency range 10 Hz to 10 MHz.
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Direct realization of the transfer function using modern fuctional blocks
Vyskočil, Jiří ; Petržela, Jiří (referee) ; Dostál, Tomáš (advisor)
The aim of my bachelor’s thesis is a direct realization of the transfer function using modern functional blocks. It is a circuit design of multifunction frequency-selection filters. A merit of the direct realization of the transfer function is for example an easy modification of the circuit design using the signal flow graph. These circuit designs can work in current and voltage modes. My task is to design a few such designs using modern function blocks. Then I verify their function and basic characteristics, I make tolerance and sensitivity analyses and lastly I scrutinize effects of parasitic phenomena and real building components.
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Unconventional Circuit Elements for Ladder Filter Design
Shaktour, Mahmoud ; Dobeš,, Josef (referee) ; Mišurec, Jiří (referee) ; Biolek, Dalibor (advisor)
Kmitočtové filtry jsou lineární elektrické obvody, které jsou využívány v různých oblastech elektroniky. Současně tvoří základní stavební bloky pro analogové zpracování signálů. V poslední dekádě bylo zavedeno množství aktivních stavebních bloků pro analogové zpracování signálů. Stále však existuje potřeba vývoje nových aktivních součástek, které by poskytovaly nové možnosti a lepší parametry. V práci jsou diskutovány různé aspekty obvodů pracujících v napěťovém, proudovém a smíšném módu. Práce reaguje na dnešní potřebu nízkovýkonových a nízkonapěťových aplikací pro přenosné přístroje a mobilní komunikační systémy a na problémy jejich návrhu. Potřeba těchto výkonných nízkonapěťových zařízení je výzvou návrhářů k hledání nových obvodových topologií a nových nízkonapěťových technik. V práci je popsána řada aktivních prvků, jako například operační transkonduktanční zesilovač (OTA), proudový konvejor II. generace (CCII) a CDTA (Current Differencing Transconductance Amplifier). Dále jsou navrženy nové prvky, jako jsou VDTA (Voltage Differencing Transconductance Amplifier) a VDVTA (Voltage Differencing Voltage Transconductance Amplifier). Všechny tyto prvky byly rovněž implementovány pomocí "bulk-driven" techniky CMOS s cílem realizace nízkonapěťových aplikací. Tato práce je rovněž zaměřena na náhrady klasických induktorů syntetickými induktory v pasivních LC příčkových filtrech. Tyto náhrady pak mohou vést k syntéze aktivních filtrů se zajímavými vlastnostmi.
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Synthesis of frequency filters with ability of the electronic reconfiguration
Theumer, Radek ; Šotner, Roman (referee) ; Langhammer, Lukáš (advisor)
This bachelor thesis deals with proposal of frequency filters providing electronic controllability of its transfer function. The main aim was to propose new filtering structures working in voltage and current mode based on suitable proposal methods. Active elements are implemented by available operational transconductance amplifiers, current amplifiers and conveyors, eventually voltage amplifiers. Four different active controllable filters are presented. Their function is simulated in software PSpice with help of models at transistor level in comparison with ideal behavior (idealized models). Two designed filtering structures were chosen and complemented on parasitic, sensitivity, stability, temperature analysis and Monte Carlo analysis. These circuits were realized on PCB. Measurement results are presented at the end of thesis, including comparison with simulations.
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Multifunctional tuned active filter
Šotner, Roman ; Petržela, Jiří (referee) ; Dostál, Tomáš (advisor)
The diploma thesis deals about design of the ARC multifunctional filters using modern functional blocks. These active blocks are for example voltage feedback operational amplifiers (OAs), operational transconductance amplifiers (OTAs), current conveyors (CCIIs) or current mode analog multipliers, current feedback amplifiers (CFAs), integrated circuits with switched capacitors building blocks (SCs) and digital potentiometers. The filters are studied with ideal circuit models and models of third level (3) based on voltage controlled voltage sources, voltage controlled current sources etc. (analog behavioral modelling). The professional macromodels are used for example LT 1364 (Linear Technology), EL 2045 (Intersil), LT 1228 (Linear Technology), LM 13700 (National Semiconductor), EL 2082 (Intersil), AD 844 (Analog Devices) and others. The circuits of the designed filters are simulated in PSpice (OrCAD), parasite effects and effects of the real parts are studied. Tuning and electronic adjusting parameters these filters are discussed and controlled by simulation in PSpice. Properties some simulated circuits are compare with experimental results. In conclusion individual filters are discussed and compared their properties. The constructional details of the some filters are presented at the end of this work.
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Analysis of methods of measurement of fully-differential frequency filters
Kučera, Tomáš ; Kubánek, David (referee) ; Jeřábek, Jan (advisor)
This bachelor thesis is analysing methods of measuring of differential frequency-selection filters with usage of active elements especially in current mode. Firstly it describes techniques of scheme of differential frequency-selection filters in current mode and conversions of linkage from voltage to current mode. Next the thesis aims at methods of measuring of particular voltage converters to differential current and back from differential current to voltage, which are an integral part for measurements of differential frequency-selection filters in current mode. For verification of characteristics of solutions designed separately as well as in cascade with particular solvent of frequency-selection filter there were used simulation instruments SNAP and OrCAD there, chosen resolutions were constructed and its characteristics were checked during laboratory test.
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