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Controllable Frequency Filters with Modern Active Elements
Preclík, Milan ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
The work deals with design of transformation cells suitable for realization of higher orders frequency filters with possibility of cutoff frequency control. At first, there is a common description of frequency filters and active elements like current and voltage conveyors. Furthermore assumptions of cutoff frequency control are defined which result in a convenient characteristical equation. Phylosophy of synthetic elements DP , EP , DS , ES including a possibility of change of cutoff frequency is next in line. By exploitation of synthetic elements theory new circuit’s schemes of transformation cells are searched. The work continues with the choice of appropriate transformation cells for resulting circuit’s solutions of frequency filters with possibility of cutoff frequency control by using transfer coefficients of active elements or with help of passive elements. The work concludes with verification of its proper function based on a simulation executed in OrCAD and with practical implementation of choosen circuit’s solution.
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Selected frequency filter design methods using non-traditional active elements
Omasta, Zdeněk ; Koton, Jaroslav (referee) ; Herencsár, Norbert (advisor)
This master’s thesis is bent on comparison of four newest method of analog frequency filter design. After the introductory part, a description of properties and internal structure of active elements (Second-Generation Current Conveyor), VG-CCII (Variable Gain Current Conveyor), VCG-CCII (Voltage and current gained second generation current conveyor) a CFTA (Current Follower Transconductance Amplifier) is mentioned. This active elements are used in subsequent design. At the next part, process of frequency filters design by generalized method of filter design flowing from the full admittance network, by extending autonomous circuits, design using the signal flow graphs theory and design with synthetic high-order elements are presented. Thirty nine autonomous circuits are derived from full admittance networks with one and two active elements CFTA. Selected autonomous circuits are used for direct design of frequency filter and for filter design by extending autonomous circuits. Produced structures guarantee the possibility of controlling the quality factor Q0 independently of the characteristic frequency f0. Three frequency filters are designed by method using the signal flow graph theory. Active elements CFTA, VG-CCI and VCG-CCII are used. Full multifunctional frequency filter with conveyors VG-CCII and VCG-CCII guarantee the possibility of controlling the quality factor Q0 and the characteristic frequency f0 independently of the each other. In last part, from 2nd to 5th order low-pass filters by the method using synthetic high-order elements are designed. The behaviour of the selected filters has been verified by simulations in the PSpice program for all of the mentioned methods separately.
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Differential frequency filters with modern active elements
Kubík, Milan ; Vrba, Kamil (referee) ; Jeřábek, Jan (advisor)
The master thesis focuses on design of fully-differential frequency filters with modern active components in current mode. First part informs about problems concerning analogue frequency filters and creating differential structures. Second part deals with methods of create filters and used active components - DACA (Digital Adjustable Current Amplifier) and MO-CF (Multiple Output Current Follower). Own design of differential filters is divided on two parts. In the first part of design results there are filters created with synthetic higher-order elements. There are presented circuit structures implementing the third order low pass filter and high pass filter. In the second part are designed filters with signal flow graphs. The first circuit implementing low pass, high pass, band pass, band rejection and all-pass filter. The second circuit is with help of the same set of current amplification by DACA components tuning of the natural frequency. For this circuit was make sensitivity analysis. In the final part is practical implementation of the differential frequency filter for tuning of the natural frequency and summarises the thesis.
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Synthesis and Analysis of Circuits with Modern Active Elements
Koton, Jaroslav ; Vrba, Kamil (advisor)
The dissertation thesis deals with the synthesis and design of active frequency filters using current (CC) and voltage (VC) conveyors, or current active elements CMI (Current Mirror and Inverter), MCMI (Multi-output CMI) and PCA (Programmable Current Amplifier). As introduction, these active elements are described as suitable for the design of the circuits working in the voltage-, current,- ,and mixed-mode, or in pure current-mode speaking about the current active elements. The new frequency filter structures presented in this thesis using the above mentioned active elements were designed by the generalized autonomous circuit method, transformation cells and signal flow-graph theory. The generalized autonomous circuit method is based on full admittance network to which generalized active elements are connected. The described admittance networks can be used for other active elements. The next method is based on the transformation cells that subsequently are used for the design of synthetic elements with higher-order imittance. Original conditions for the design of such blocks are given that lead to maximal simplicity of the final structure with minimal number of passive and active elements. For effective usage of another method utilizing signal flow-graphs, new reduced graphs of chosen active elements are given. Their usage leads to direct function blocks synthesis with required properties. The functionality and behavior of chosen circuit solutions have been verified by analyses in simulation programs. The active elements were simulated by the universal current conveyor (UCC) or universal voltage conveyors (UVC) that were designed at the FEEC, BUT in cooperation with AMI Semiconductor Design Centre Brno with the CMOS 0.35 m technology. These active elements have been also used for the realization of chosen filter structures. The experimental measurements were performed in the in the frequency range 10 KHz to 100 MHz.
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Synthetic Circuit Elements with Higher-Order Immittance with Controlled Current Sources
Popelka, Petr ; Vrba, Kamil (referee) ; Kubánek, David (advisor)
This thesis deals with design and use synthetic circuit elements with higher-order immittance with controlled current sources to implement the frequency filters. Controlled current sources which are derived from the voltage variations are presented. They are current follower, current invertor and current operational amplifier. Low-pass and high-pass filter which are used synthetic elements are simulated on computer. The influence of real properities of active elements and passive elements tolerances on filter functionality is investigated. Selected circuit of frequency filter is realized and measured the frequency characteristic.
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Synthetic immittance dipoles using active current elements
Mráka, Michal ; Jeřábek, Jan (referee) ; Koton, Jaroslav (advisor)
This master thesis discusses the design of Synthetic immittance dipoles using active current elements. The introduction presents aktive current elemetns MO-CF and DACA as buildings blocks for analog filters that are able to process signals with frequencies up to ten megahertz. Methods of synthetic elements using active current elements design is described in this thesis.Is resulted from full addmitances net which contains one active current element Subsequently there are designed various types of frequency filters working in current mode. The functionality of designed filters was verified by computer simulation. Selected designed filter were practically verified with commercially available elelments and active element MO-CF. Measurements in the frequency domain were carried on. On all of types of filters are made sensitivity analysis.
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Frequency filters using voltage conveyors
Dohnal, Pavel ; Vrba, Kamil (referee) ; Minarčík, Martin (advisor)
The topic of this bachelor´s thesis was frequency filters and their realization using voltage conveyors. The main goal of my thesis was design and simulation of frequency filters with voltage conveyors through two different methods. At first there were found filters second order with voltage conveyors using autonomous circuits. These circuits resulted from total admitance net. Then the frequency filters using voltage conveyors were solve through synthetic components. At the beginnig of this project the frequency filters, their characteristics, realizations and types were defined. Then were designed basic properties of current conveyors, from which we can derive voltage conveyors. The voltage conveyors are basic building components of my thesis. There were defined individual types of voltage conveyors and their close specification. There was defined universal voltage conveyor. Through the universal voltage conveyor we can realize all types of voltage conveyors. After the definition of useful species there were designed the frequency filters second order using voltage conveyors with four passive components using the total admitance net. There were found 44 these circuits. Then one of these circuits was selected and this circuit was simulated to lowpass and hipass. Subsequently the other method was used, where were used the synthetic components to creation of filters secon order. The circuits resulted from autonomous circuits, which were produced by the first method. 25 of these autonomous circuits were usable for this method. One of these circuits was simulated to lowpass and hipass.
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Synthesis and Analysis of Circuits with Modern Active Elements
Koton, Jaroslav ; Vrba, Kamil (advisor)
The dissertation thesis deals with the synthesis and design of active frequency filters using current (CC) and voltage (VC) conveyors, or current active elements CMI (Current Mirror and Inverter), MCMI (Multi-output CMI) and PCA (Programmable Current Amplifier). As introduction, these active elements are described as suitable for the design of the circuits working in the voltage-, current,- ,and mixed-mode, or in pure current-mode speaking about the current active elements. The new frequency filter structures presented in this thesis using the above mentioned active elements were designed by the generalized autonomous circuit method, transformation cells and signal flow-graph theory. The generalized autonomous circuit method is based on full admittance network to which generalized active elements are connected. The described admittance networks can be used for other active elements. The next method is based on the transformation cells that subsequently are used for the design of synthetic elements with higher-order imittance. Original conditions for the design of such blocks are given that lead to maximal simplicity of the final structure with minimal number of passive and active elements. For effective usage of another method utilizing signal flow-graphs, new reduced graphs of chosen active elements are given. Their usage leads to direct function blocks synthesis with required properties. The functionality and behavior of chosen circuit solutions have been verified by analyses in simulation programs. The active elements were simulated by the universal current conveyor (UCC) or universal voltage conveyors (UVC) that were designed at the FEEC, BUT in cooperation with AMI Semiconductor Design Centre Brno with the CMOS 0.35 m technology. These active elements have been also used for the realization of chosen filter structures. The experimental measurements were performed in the in the frequency range 10 KHz to 100 MHz.
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Frequency filters using voltage conveyors
Dohnal, Pavel ; Vrba, Kamil (referee) ; Minarčík, Martin (advisor)
The topic of this bachelor´s thesis was frequency filters and their realization using voltage conveyors. The main goal of my thesis was design and simulation of frequency filters with voltage conveyors through two different methods. At first there were found filters second order with voltage conveyors using autonomous circuits. These circuits resulted from total admitance net. Then the frequency filters using voltage conveyors were solve through synthetic components. At the beginnig of this project the frequency filters, their characteristics, realizations and types were defined. Then were designed basic properties of current conveyors, from which we can derive voltage conveyors. The voltage conveyors are basic building components of my thesis. There were defined individual types of voltage conveyors and their close specification. There was defined universal voltage conveyor. Through the universal voltage conveyor we can realize all types of voltage conveyors. After the definition of useful species there were designed the frequency filters second order using voltage conveyors with four passive components using the total admitance net. There were found 44 these circuits. Then one of these circuits was selected and this circuit was simulated to lowpass and hipass. Subsequently the other method was used, where were used the synthetic components to creation of filters secon order. The circuits resulted from autonomous circuits, which were produced by the first method. 25 of these autonomous circuits were usable for this method. One of these circuits was simulated to lowpass and hipass.
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Differential frequency filters with modern active elements
Kubík, Milan ; Vrba, Kamil (referee) ; Jeřábek, Jan (advisor)
The master thesis focuses on design of fully-differential frequency filters with modern active components in current mode. First part informs about problems concerning analogue frequency filters and creating differential structures. Second part deals with methods of create filters and used active components - DACA (Digital Adjustable Current Amplifier) and MO-CF (Multiple Output Current Follower). Own design of differential filters is divided on two parts. In the first part of design results there are filters created with synthetic higher-order elements. There are presented circuit structures implementing the third order low pass filter and high pass filter. In the second part are designed filters with signal flow graphs. The first circuit implementing low pass, high pass, band pass, band rejection and all-pass filter. The second circuit is with help of the same set of current amplification by DACA components tuning of the natural frequency. For this circuit was make sensitivity analysis. In the final part is practical implementation of the differential frequency filter for tuning of the natural frequency and summarises the thesis.
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