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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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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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Electronic tunable harmonic oscillator
Veselý, Jiří ; Jeřábek, Jan (referee) ; Šotner, Roman (advisor)
This masters project describes properties and primary parameters of active function blocks (OPA, VCA, OTA, CFA, CC) usable in construction of harmonic oscillators. Basic principles of harmonic generators, especially feedback oscillators, are introduced. In next section are presented five particular schematics of harmonic tuned oscillators. For this oscillators are indicated basic formulas, essential qualities performed by simulations and results of sensitivity and tolerance analysis. In the last part of diploma thesis there are selected three circuits which are made and their features are measured.
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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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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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Synthesis of differential filtering structures with complex active elements
Pánek, David ; Kubánek, David (referee) ; Langhammer, Lukáš (advisor)
This document is focused on already existing single-ended frequency filters with modern active components working in current mode and their modification into fully-differential ended form. After the modification both versions were compared between each other. The first part informs about problems concerning analogue frequency filters. The second part deals with used active components - MO-CF (Multiple Output Current Follower), BOTA (Balanced transconductance amplifier), UCC (universal current conveyor), VDTA (Voltage differencing transconductance amplifier), CDTA (Current differencing transconductance amplifier) and VDCC (voltage differencing current conveyor). Four circuits have been chosen and transformed into their differential form. Two circuits have been chosen and realised into PCB and then practicaly measured in a laboratory. The last part is a summary of simulations and measured results and check of circuits behavior result.
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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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Design of frequency filters with non-traditional transconductance elements
Gajdoš, Adam ; Vrba, Kamil (referee) ; Jeřábek, Jan (advisor)
The aim of Bachelor’s thesis was to study, design and practically realize controllable frequency filters, working in the current mode, using non-traditional active elements, containing a combination of transconductance amplifiers with current conveyors. Thesis deals in the theoretical part with the basic division of frequency filters, operating modes of circuits and design method of signal flow graphs, which are used for design of the circuits in the practical part. The next section describes all the active elements that are used for circuits realization. In the practical part five circuits are designed with the element VDCC and one circuit with CCTA. Simulation is performed on all circuits using a previously defined model of the real UCC. Last part of thesis describes the design of the PCB and the results of experimental measurements for chosen circuit.
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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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