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Mutlifunctional electronically adjustable KHN filters
Harsa, Jan ; Petržela, Jiří (referee) ; Šotner, Roman (advisor)
In the bachelor thesis some types of KHN filters are analyzed and presented. Filters contain various active elements and they works in the current, voltage and hybrid mode. Great attention is paid to the so-called diamond transistor, which may represent different functional blocks (amplifier with current feedback link, transconductance amplifier and current conveyor) in these circuits. Attention is also paid to the possibility of tuning the filter, which consists in changing the characteristic frequency and quality factor independently. Tuning is achieved by using electronically tuneable active blocks such as voltage controlled operational amplifiers or analogue multipliers. Adjustability is also realized by tuneable passive components (potentiometers). Circuits are tested using the simulation program PSpice. Simulations are performed with professional macromodels, such as model OPA860 or VCA610 (Texas Instruments). In the thesis are results for sensitivity and tolerance analysis, which were gotten with third-level models. The optimization is also resolve for parameters of tuneable filters. The characteristics of the filter operating in voltage mode were verified by measurement.
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Design of the high frequency tunable oscillators
Malec, Tomáš ; Vochyán, Josef (referee) ; Petržela, Jiří (advisor)
This paper deals with the simplest structure capable of generate harmonic signals of high frequency and stable amplitude. As essential elements of these oscillators have been used active blocks known as diamond transistors. The proposal was given to minimize the number of components and smooth electronic retuning. These proposed districts have been theoretically analyzed by the program PSpice and practically verified. The document contains the results of these reviews and readings focusing on the total harmonic distortion, frequency agility and range of phase noise.
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Applications of multi-output active elements in current-mode
Maňas, Stanislav ; Jeřábek, Jan (referee) ; Šotner, Roman (advisor)
Bachelor's thesis deals with analyzing the characteristics of the block in current mode CCII and its applications. The first part is devoted to the theory of CC block, the theory of CCII block his peripheral involvement and exploration properties. The second part is a third model levels and this is carried out sensitivity and tolerance analysis of individual involvement. The third part is a block CCII surveyed as part of participation frequency filters and oscillators. One involvement has been experimentally tested. At the end of each subsection is obtained by a comparison of the characteristics of individual involvement.
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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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Higher-order current mirror filters
Semmler, Petr ; Jeřábek, Jan (referee) ; Lattenberg, Ivo (advisor)
The bachelor's thesis deal with designing frequency filters fourth and sixth rule with current component CMI, GCMI and MCMI and with multi-output current mirrors. The introduction presents basic information about frequency filters divided base several views. Next information attention about current mirrors with divided base several views. Theory part is closed information about current component GCMI, CMI, MCMI. Second part my bachelor's thesis deal manual designing frequency filter with method of autonomous circuits. This method were designed several circuit for fourth and sixth rule. Then he was always one circuit selected for the final analysis, an analysis was performed using program PSpice and Snap. The last section is devoted to the replacement of components of current mirrors. It analyzed the functionality of current mirrors including verification of the functionality of filters incorporating current mirrors.
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Frequency filters with tunable current amplifier
Jemelík, Lukáš ; Lattenberg, Ivo (referee) ; Jeřábek, Jan (advisor)
The bachelor thesis deals with the designing of active frequency filters of the second – order which are make use of active elements. These filters were designed by means of autonomous circuits. Digitally Controlled Current Amplifier DCCA and Multiple Output Current Follower MO-CF were used as active elements. Designed filters works in current mode. The bachelor thesis is divided into five chapters. In the introductory part there are described general characters of frequency filters, the second part contains the description of the active elements, the third part includes the method of construction high – order filters. In fourth part there are described particular circuitry, their transmission functions and confirmation of their functionality in computer software.
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Fully-differential current mode frequency filters
Kubík, Milan ; Koton, Jaroslav (referee) ; Jeřábek, Jan (advisor)
The bachelor thesis focuses on design of fully-differential frequency filters in current mode. First part informs about problems concerning frequency filters and creating differential structures in current mode. Second part deals with used active components - Digitally Controlled Current Amplifier (DCCA) and Multiple Output Current Follower (MO-CF). Key point is own design of differential filters, which is divided into three parts. In the first part of design results there are filters obtained with help of models from FilterPro software. There are presented circuit structures implementing low pass, high pass and band pass frequency filters. At the next part two filters derived from autonomous circuits. These circuits are working as low pass and high pass frequency filters. In the last part are designed two types of integrator type components – loss integrator and lossless integrator. These circuits were used to realize cascade connection achieving three filtering function – band pass 1, band pass 2 and low pass. Final part summarises the thesis and features of designed structures.
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Current-mode tunable frequency filters
Prekop, Pavel ; Kubánek, David (referee) ; Jeřábek, Jan (advisor)
In first part of my bachelor’s thesis I deal with the matter of frequency filters, types of transferential functions, possibilities and reasons using active filters. In next part of my thesis I submit various types of active elements especially elements working in current mode. My thesis also deals with various techniques that we can use when creating frequency filters. In last part of my thesis I submit design some filters, as well as final simulations in a OrCAD software.
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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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Active frequency filter using current mode
Paščinský, Jiří ; Dostál, Tomáš (referee) ; Slezák, Josef (advisor)
The aim of this work is design of frequency filter working in current mode. The introduction of the work deals with features and applications of frequency filters. Special attention is paid to the transfer function of the filter. In third chapter different operational modes of electrical circuits and their advantages and disadvantages are discussed. Attention is paid to active blocks suitable for circuits working in current mode. There is description of components AD844 and EL2082 which represent current conveyors of the second generation and are used in the designed filter. The last two chapters deal with design of component values of the frequency filter. The designed circuit was simulated in PSpice and the results were compared with measurments. Also sensitivity and tolerance analysis of the filter were performed.
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