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Design of frequency filters with non-traditionally combined active elements
Danyi, Ivo ; Koton, Jaroslav (referee) ; Jeřábek, Jan (advisor)
This paper discusses the frequency second-order filters that work in the current mode. As active elements are used VDTA (voltage differential transconductance amplifier) and CCTA (Current Conveyor Transconductance Amplifier) design method as a method is used to graph of signal flow. They are designed and analyzed four frequency filters. The first uses only one element VDTA and is a multifunctional frequency-controllable frequency filter of the second order. The second is composed of two elements, is VDTA fully controllable multifunctional frequency filter of the second order. The third uses one element CCTA represents a multifunctional frequency filter of the second order without control. The fourth element uses a single CCTA and VDTA and is a multifunctional frequency-controlled frequency filter of the second order. All frequency filters are subjec- ted to sensitivity analysis and simulated for ideal and non-ideal active element. Second circuit wiring with two VDTA elements is realized and analyzed the characteristics of this filter.
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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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Non-linear circuit structures with active current elements
Langhammer, Lukáš ; Lattenberg, Ivo (referee) ; Koton, Jaroslav (advisor)
This thesis deals with non-linear curcuit structures with current active elements. In its introduction this work deals with a description of the current conveyor. Further the text pays attention to the possiblities of the circuits for modification signals in analogue technology. First are described circuits of diode limiters and transducer. Great attention is paid to the amplifiers with current active parts. In conclusion are realized circuits of universal precise full-wave rectifiers using operational amplifier and current conveyor and made comparisons.
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Universal active elements and their usage in frequency filters
Vencálek, Roman ; Kubánek, David (referee) ; Herencsár, Norbert (advisor)
This master’s thesis deals with the advanced universal modern active elements, such as the current and voltage conveyors. The problem with small bandwidth has been fixed due to the quick development in recent years. Current and voltage conveyors are still being researched. The good properties of conveyors promise their possible commercial usage in the future. For the research of current conveyors we can use parts of other integrated circuits and thus get elements with similar properties. This thesis suggests how to make an active filter using the DBTA and FDBTA elements which were created by “combination” of the universal current and voltage conveyor. Simulations were carried out on selected circuits containing the DBTA to verify their properties. It was for finding out about their behaviour in real applications that the circuits were constructed. This enabled the comparison of the results acquired from the simulation programs with the ideal behaviour of the elements and with the models simulating real properties against the values acquired by measurements of the circuits.
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Behavioral Model of Current Conveyor with Advanced Controllable Inter-Terminal Relations
Jagla, Lukáš ; Langhammer, Lukáš (referee) ; Šotner, Roman (advisor)
Bachelor's thesis deals with model of current conveyor with advanced controllable inter-terminal relations. The behavioral model based on commercially available active devices has been proposed and designed as real implementation (including BCP design for experiments). Features of the behavioral model are verified by PSpice simulations as well as by experiments. Proposed device is utilized for synthesis and design of unconventional types of electronically controllable sine-wave oscillators and electronically adjustable filters. Simulated characteristics of the behavioral model as well as proposed applications are compared with experiments.
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Linear system stability analysis
Jelen, Michal ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
This bachelor’s thesis will be dealing with stability analysis of linear systems. In theoretical part will be mentioned stability and its conditions, stability criteria, their partition to groups and description of each criterion. In practical part will be chosen one stability criterion which will be working with afterwards. As examined circuit will be a filter with current conveyors as active elements which will be obtained a characteristic multinomial from. There will be working with transmittion functions of single and double pole model in examples. It will be created a computer programme which will enable an automatization of Routh’s stability criterion and plot graphical outputs in dependence on input parameters and their values.
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Frequency filters using current active elements
Homola, Radek ; Lattenberg, Ivo (referee) ; Koton, Jaroslav (advisor)
This master´s thesis is about MO-CF, DCCA and CC frequency filters with current active elements proposal. Current active elements, their features, structure and utilization are shown in introduction. A progress propose of universal filter is described in thesis. With the use of active elements has been established an universal filter with basic parameter changes capability (quality and limit frequency). SNAP software was used in this propose and the characteristics simulation have been done in OrCad-PSpice. For control changes of quality and limit frequency was used active element DCCA. The main circuit board of universal controlled filter was made with the EAGLE software. Created sample was measured for each type of filter, the different quality and limit frequency. These values were compared with simulated values of the filter.
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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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Differential and pseudo-differential filtering circuits
Hrbek, Tomáš ; Bečková, Zuzana (referee) ; Jeřábek, Jan (advisor)
This bachelor thesis deals with analog frequency filters operating in differential and pseudodifferential mode. It is focused on active filters second order that use modern active elements. For specific solution is analyzed the ability to control filter parameters. It also deals with the design of fully differential filters and transformations from non-differential filters. The thesis analyzes three specific filtering solutions with which ideal simulations and simulations using third order models are performed. A printed circuit is constructed for one filter solution, its parameters are measured and compared with simulations.
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