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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 nontraditional active elements
Dvořák, Jan ; Koton, Jaroslav (referee) ; Jeřábek, Jan (advisor)
Bachelor's thesis deals with designs of fully-differential frequency filters which operate in current mode where it is possible to control their parameters by change the transconductance or the amplification. The first part divides and describes in general frequency filters. Furthermore, there are described active elements together with their simple simulation models. The second part describes the design of frequency filter by M-C signal-flow graph and methods of transforming final circuit to fully-differential structure. Next part presents several structures of the second-order filter with their simulations in non-differential and fully-differential forms. Last part presents designs of boards of printed circuits and measurement results of two chosen circuits.
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Analysis of differential and non-differential filtering structures with adjustable current amplifier
Dvořák, Jan ; Vrba, Kamil (referee) ; Jeřábek, Jan (advisor)
The master thesis deals with designs of the single-ended and the fully-differential secondorder frequency filters with adjustable parameters. This filters operate in the current mode where main element is the current amplifier DACA (Digitally Adjustable Current Amplifier). The first part describes basic behaviour of frequency filters and distribution according to filter funcion, used parts and structure. The second part of thesis describes the design of the frequency filters by the M-C signal-flow graphs and the transformating single-ended structures to the fully-differential forms. The next part deals with properties of the active elements and their simulation models. The following part describe six circuits of the frequency filters with adjustable parameters and their simulations. Four simulation models with different properties were used for simulating of the DACA in the each circuits. The last part deals with the practical design and measurement of the selected frequency filters.
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Frequency filters with untraditional combination of active elements
Filgas, Jaroslav ; Herencsár, Norbert (referee) ; Jeřábek, Jan (advisor)
The Bachelor’s thesis deals with the theory and designing of analog frequency filters of the second order, which operate in current mode and use the untraditional combination of active elements. The filters are designed by means of the autonomous circuits. Active elements used in the design is Multiple Output Current Follower MO-CF, Digitally Controlled Current Amplifier DACA, Generalized Current Mirror and Inverters GCMI, Balanced Operational Transconductance Amplifier BOTA, Inverting Current Conveyor 1st and 3rd Generation ICCI/ICCIII and Universal Voltage Conveyor UVC. The proposed filters work in current mode and their ideal and real models are verified in the simulation environment OrCad. The thesis is structured into five chapters including the conclusion. The first chapter gives the general characteristics of the frequency filters, types of filter functions, types of filters and general equations. The second chapter is devoted to the theory of the active elements. The third charter is about methods of designing and the fourth includes custom designed filters, including their transfer functions and the results verify their functionality in the simulation environment.
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The Tolerance Analysis of Filters with CDTA
Miksl, Jan ; Jeřábek, Jan (referee) ; Šotner, Roman (advisor)
The bachelor thesis deals with the concept, design, modeling, tolerance and sensitivity analysis of the KHN filter using CDTA. The first part contains theoretical introduction about filters and their general properties. Secondly, the CDTA element, its block structure, schematic symbol as well as its circuit features are defined. Standard KHN filter structure with operational amplifiers is simulated. Results of this simulation are used for comparison with simulations results of CDTA KHN filter structure. The multifunctional CDTA KHN filter structure is simulated using ideal CDTA models, third-level models and models based on professional macromodels of attainable components (AD 844, MAX 435). Then tolerance and sensitivity analyses are explained and described. The following section discusses ways of modifying the structure and design KHN structure with CDTA models 3rd level. In the last chapter the circuit is optimized using PSpice and the attention is focused on achieving the best possible involvement of the typical characteristics of the elements of tolerance. In conclusion, the results of simulations are evaluated, compared the characteristics of circuit before and after optimization, and mention the advantages and disadvantages of filter elements with CDTA.
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Analysis, features and applications of available current mode multipliers
Miksl, Jan ; Jeřábek, Jan (referee) ; Šotner, Roman (advisor)
The diploma thesis deals with analysis, validation, measurement of parameters of the commercially available current multiplies (namely the EL2082 and EL4083) and their applications in practice. Control analysis are carried out in OrCAD PSpice program and compared with values from datasheets. Control analysis are focused on AC and DC characteristics of these active blocks. There are discusses the input impedance, the output impedance, the current gain and the possibility of electronic adjusting. The parameters of the elements were verified by measurements. Proposals for circuit applications (selective circuit, oscillator, frequency filter) with EL2082 and EL4083 are presented and analyzed in the program OrCAD. Three oscillator circuit designs are experimentally tested and the results are compared with the theoretical expectations and simulations in OrCAD. The possibility of electronic control for oscillators is examined. Also the sensitivity and the tolerance analysis are carried out. The constructional details of oscillators are presented at the end of this work.
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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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Pseudo-differential higher-order frequency filters
Jeleček, Jiří ; Dvořák, Jan (referee) ; Sládok, Ondřej (advisor)
This Master's thesis deals with pseudo-differential frequency higher order filters working in voltage mode. The thesis deals with the description of frequency filters, their types and applications. Follows an analysis of differential and pseudo-differential transmissions. Next part contains a description of used active elements (conveyors) at thesis (CCII, DVCC, DDCC, UCC). In the last part the thesis is devoted to the own design of the pseudo-differential filter. Design functionality is verified by experimental simulation.
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Electronically Configurable Transfer Structures
Langhammer, Lukáš ; Hospodka, Jiří (referee) ; Vávra, Jiří (referee) ; Šotner, Roman (advisor)
Práce se zaměřuje na vývoj a výzkum v oblasti elektronicky rekonfigurovatelných přenosových struktur. Primárním cílem je návrh těchto struktur za užití moderních elektronicky řiditelných aktivních prvků. V práci je prezentováno množství elektronicky rekonfigurovatelných filtračních struktur, jež byly vytvořeny za užití různých návrhových metod. Důraz je dále kladen na možnost řídit některý z typických parametrů filtru pomocí řiditelných aktivních prvků. Práce dále obsahuje několik obvodových návrhů aktivních prvků či stavebních bloků s vhodně řešenou elektronickou řiditelností, tak, aby tyto prvky/bloky mohly být dále použity pro návrh elektronicky rekonfigurovatelných filtrů. Správnost návrhu jednotlivých zapojení je podpořena PSpice a Cadence simulacemi s modely na tranzistorové úrovni. Vybraná zapojení jsou dále realizována za pomocí dostupných aktivních prvků a podrobena experimentálnímu měření.
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Differential and pseudo-differential frequency filters
Sládok, Ondřej ; Herencsár, Norbert (referee) ; Koton, Jaroslav (advisor)
This thesis deals with fully differential and pseudo-differential frequency filters. Significant emphasis is placed on the characteristics of common-mode signal. Further, the text deals with the design issue of fully-differential structure and transformation of non-differential to pseudo-differential structures. In the thesis one non-differential structure, one fully-differential and three pseudo-differential structures are proposed, one of them working in current mode. The thesis also describes the analysis from the perspective of non-ideal properties of the active element of two circuit solutions, which is trying to find the optimal solution. In each case, functionality of new solutions is verified by simulations and in several cases also by experimental measurement.
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