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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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Fully-differential frequency filter designing with current active elements using signal-flow graphs method
Štork, Petr ; Jeřábek, Jan (referee) ; Langhammer, Lukáš (advisor)
This master’s thesis deals with designing of fully-differential current-mode frequency filters using signal-flow graphs method. The first part is focused on a general description of frequency filters, its function and division. Active elements that create these frequency filters, such as multi-output current follower (MO-CF), balanced or multi-output transconductance amplifier (BOTA, MOTA) and digitally adjustace current amplifier (DACA) are described in the following part. Next, problems and various techniques of designing such filters are discussed on a theoretic basis. In the remaining part of the thesis there are six circuits of frequency filters described in detail; these connections are then transferred of passive elements to a proposed connections, with the assistance of a so-called reflection. Calculations of passive form are stated, as well as results of simulations, where nondifferential and differential variations of these designed frequency filters are compared. Finaly, it has been selected some variants of designs, which has been manufactured, then measured out and resulet has been compare between each other.
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Synthesis of the electronically reconfigurable frequency filters
Michalička, Filip ; Dvořák, Jan (referee) ; Langhammer, Lukáš (advisor)
This diploma thesis deals with design of reconection-less electronically reconfigurable filter structures which have single input and single output using unconventional active elements, which have ability to adjust one of their parameter e.g. gain or transconductance. The first part describes basic parameters of frequency filters, the division of filters by frequency transfer response and used circuit elements, their operational modes, the principle of reconnection-less electronically reconfiguration and the circuit design method MUNV. Second part describes all active elements used in the proposal of filters, their properties and the implementation using existing transistor-level models. The third part contains the design of three reconnection-less electronically reconfigurable filters and the simulations results obtained from simulation programs OrCAD Capture and PSpice. The obtained results were compared with theoretical behaviour. This part also contains results of these analyses: sensitivity, parasitic, Monte Carlo and temperature to determine the behaviour in varied cases.
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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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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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Application possibilities of LNVGA programmable amplifier
Sobotka, Josef ; Hanák, Pavel (referee) ; Jeřábek, Jan (advisor)
This thesis deals with the theoretical description of the qualitative characteristics and parameters of some modern active elements, also discusses the theory of signal flow graphs at the level applicable for the following frequency filter design methods. The thesis is also generally discussed the issue with the circuit simulator PSpice modeling theory and voltage amplifiers on the basic 6-levels. The practical part of the work is divided into two parts. The first practical part is dedicated to design four levels of simulation model of components LNVGA element. The second practical part contains detailed theoretical proposals for three circuit structures implementing the frequency filters 2nd order (based on the basic structure of the OTA-C) using signal flow graphs with configuration options of Q and fm based on the parameters of active elements in the peripheral structure and their verification with prepared LNVGA model layers.
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Synthesis of electronically configurable filters with modern active elements
Hricko, Tomáš ; Šotner, Roman (referee) ; Langhammer, Lukáš (advisor)
This bachelor thesis is concerned of proposal electronically configurable filters. The first part describes the basic division of frequency of filters and working modes alongside with the principle of electronically configuration. All active elements used in the proposal of presented circuit solutions are defined in the second section. The third part consist of the design of three circuits of electronically configurable filters and comparison of theory with simulation results obtained from program OrCAD PSpice. The concluding part of the work compares the experimental results of the implemented filters with the PSpice simulations.
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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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Fully-differential frequency filters with controllable active elements
Zapletal, Miroslav ; Polák, Josef (referee) ; Langhammer, Lukáš (advisor)
This bachelor thesis deals with the fully-differential frequency filters that work in current-mode and the tunability is made possible by active elements. In the first part we will deal with theoretical analysis of frequency filters, and a closer approximation of a filter design method. The second part deals with designing of frequency filters using signal-flow graphs method, converting not differential structures to differential structures and comparing the results of proposed filters. In the third part will be made up our suggested filter. It will be also measured out in VUT laboratory to verifying his functionality. Last we will compare results of real detect values of differential and not differential connection. The last part is the conclusion, in which an assessment of the whole work is made.
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