• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 4
  • Tagged with
  • 13
  • 13
  • 13
  • 9
  • 8
  • 8
  • 8
  • 7
  • 7
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

REALIZATION OF CASCADE OF RESONATORS WITH DISTRBUTED FEED-BACK SIGMA-DELTA

Saleem, Jawad, Malik, Abdul Mateen January 2009 (has links)
<p>The Sigma Delta Modulator (SDM) based analog to digital conversion is cost effective and have the advantages as higher reliability, increased functionality, and reduction in chip cost.</p><p>The thesis work includes the modeling of SDM with the signal flow graph in Matlab, optimization of the coefficients to improve the noise transfer function and signal transfer function. A procedure to find the maximum stable input range for the design. Scaling the inputs of the integrator so that the maximum output signal can be obtained according to the operational transconductance amplifier (OTA) output range. Further we derived error bound for the design. Then step by step realization of the SDM form the signal flow graph (SFG) to a fully differential switched-capacitor (SC) network is shown. The work also includes complete differential transistor level realization for 3-bit flash analog to digital converter (ADC), thermometric to binary encoder, a switch-capacitor digital to analog converter (DAC) circuit and an on-chip circuit realization of the non-overlapping clock generation circuitry.</p>
2

Realization of Cascade of Resonators with Distributed Feed-Back Sigma-Delta

Saleem, Jawad, Malik, Abdul Mateen January 2009 (has links)
The Sigma Delta Modulator (SDM) based analog to digital conversion is cost effective and have the advantages as higher reliability, increased functionality, and reduction in chip cost. The thesis work includes the modeling of SDM with the signal flow graph in Matlab, optimization of the coefficients to improve the noise transfer function and signal transfer function. A procedure to find the maximum stable input range for the design. Scaling the inputs of the integrator so that the maximum output signal can be obtained according to the operational transconductance amplifier (OTA) output range. Further we derived error bound for the design. Then step by step realization of the SDM form the signal flow graph (SFG) to a fully differential switched-capacitor (SC) network is shown. The work also includes complete differential transistor level realization for 3-bit flash analog to digital converter (ADC), thermometric to binary encoder, a switch-capacitor digital to analog converter (DAC) circuit and an on-chip circuit realization of the non-overlapping clock generation circuitry.
3

Řiditelné filtry s maximálním možným přeladěním a netradičními aktivními prvky / Adjustable filters with utmost tuning and untraditional active elements

Voráč, Ladislav January 2010 (has links)
The thesis is paid to design frequency filters steerable jet active elements of the MO–CF (Multiple-Output Current Follower) and also newly-developed current active element DACA (Digitally Adjustable Current Amplifier) in the company ON Semiconductor. The first three chapters focus on basic properties of frequency filters, used components and circuit design methods. The digitally controllable current amplifier DACA is used for managing the radio frequency filters and adjust it using the current amplification parameter A through the digital input CTR. For the design of filters of the second order a method of M-C Signal flow graphs is used. This method is in the work proved very useful and contributed to the modification of already designed frequency filters. The fourth chapter describes the actual detailed design of circuits with quality management, or marginal frequencies to the two parameters. Involvement of the proposed filter is simulated in the OrCAD program for different levels of models of the circuit elements. At the end of each filter design there is a comparison of theoretical and simulated values of the adjustable parameters circuit. The conclusion was one of the districts selected for experimental verification, followed by comparing the measured and simulated transmission characteristics.
4

Interacting Hopf Algebras- the Theory of Linear Systems / Interacting Hopf Algebras - la théorie des systèmes linéaires

Zanasi, Fabio 05 October 2015 (has links)
Dans cette thèse, on présente la théorie algébrique IH par le biais de générateurs et d’équations.Le modèle libre de IH est la catégorie des sous-espaces linéaires sur un corps k. Les termes de IH sont des diagrammes de cordes, qui, selon le choix de k, peuvent exprimer différents types de réseaux et de formalismes graphiques, que l’on retrouve dans des domaines scientifiques divers, tels que les circuits quantiques, les circuits électriques et les réseaux de Petri. Les équations de IH sont obtenues via des lois distributives entre algèbres de Hopf – d’où le nom “Interacting Hopf algebras” (algèbres de Hopf interagissantes). La caractérisation via les sous-espaces permet de voir IH comme une syntaxe fondée sur les diagrammes de cordes pour l’algèbre linéaire: les applications linéaires, les espaces et leurs transformations ont chacun leur représentation fidèle dans le langage graphique. Cela aboutit à un point de vue alternatif, souvent fructueux, sur le domaine.On illustre cela en particulier en utilisant IH pour axiomatiser la sémantique formelle de circuits de calculs de signaux, pour lesquels on s’intéresse aux questions de la complète adéquation et de la réalisabilité. Notre analyse suggère un certain nombre d’enseignements au sujet du rôle de la causalité dans la sémantique des systèmes de calcul. / We present by generators and equations the algebraic theory IH whose free model is the category oflinear subspaces over a field k. Terms of IH are string diagrams which, for different choices of k, expressdifferent kinds of networks and graphical formalisms used by scientists in various fields, such as quantumcircuits, electrical circuits and Petri nets. The equations of IH arise by distributive laws between Hopfalgebras - from which the name interacting Hopf algebras. The characterisation in terms of subspacesallows to think of IH as a string diagrammatic syntax for linear algebra: linear maps, spaces and theirtransformations are all faithfully represented in the graphical language, resulting in an alternative, ofteninsightful perspective on the subject matter. As main application, we use IH to axiomatise a formalsemantics of signal processing circuits, for which we study full abstraction and realisability. Our analysissuggests a reflection about the role of causality in the semantics of computing devices.
5

Vybrané metody návrhu kmitočtových filtrů s netradičními aktivními prvky / Selected frequency filter design methods using non-traditional active elements

Omasta, Zdeněk January 2009 (has links)
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.
6

Využití grafů signálových toků k návrhu diferenčních filtrů / Utilization of signal-flow graphs in design of the fully-differential filters

Žůrek, Radomil January 2010 (has links)
The dissertation deals with the design of fully differential frequency filters using the signal flow graphs. It presents the procedures for designing frequency filters, focusing on the active elements such as multiple-output current followers (MO-CF) and digitally adjustable current amplifiers (DACA), which work in a current mode. It is theoretically discussed the issue of designing the M-C graphs, which are the graphic analogy of voltage and current incidence matrices. There are also presented three designs of 2nd order frequency filter circuits using the indirect method of design by M-C graphs and one circuit design using the direct method. The results of each simulation and measurement are presented in a module frequency characteristics. Finally, there is a summary of M-C graphs characteristics and applicability.
7

Návrh plně diferenčních kmitočtových filtrů s proudovými aktivními prvky za pomoci metody grafu signálových toků / Fully-differential frequency filter designing with current active elements using signal-flow graphs method

Štork, Petr January 2014 (has links)
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.
8

Hierarchical Modeling of Manufacturing Systems Using Max-Plus Algebra

Imaev, Aleksey A. January 2009 (has links)
No description available.
9

Transformační návrhová metoda filtrů vycházející z pasivních struktur / Transform-based filter design technique based on passive structures

Venclovský, Martin January 2009 (has links)
This diploma thesis deals with transformation of passive elements in filter structures onto substitutes with new active element CFTA. A basic characteristic, types of filters, their frequency characteristics and a form of transfer functions are listed in an introduction. After it is introduced a development of signal flow graphs, single type of graphs and their modifications. There is specified the method Mason-Coates graphs which proves as optimal for analysis circuits. There are listed rules for a correct evaluation and make-up the graphs. Further are described active elements CFTA, CDTA and a current conveyor. There are defined active substitutes to a floating and grounded inductance, a floating capacitor and also a floating and grounded resistor in this thesis. Here, there are also designed substitutes to parallel combinations of floating passive elements. All substitutes use CFTA as an active element and the grounded capacitor as a passive element of substitute. There are presented forms of M-C graphs, transfer functions and equations for calculation passive elements of substitute at created equivalents. Functionality of designed substitutes is always verified on second order passive filters by the help of a PC simulation. There are tabular listed defined equivalents with corresponding signal graphs, transfer functions and equations for calculation capacitor of substitute are here tabular listed too. In this work there are defined two ways of connecting defined substitutes within the scope of one circuit that can be used as a simple connection or integration bounded elements. In the case of usage of the integration bounded elements it is possible to reduce total number used active elements. The usage defined substitutions are verified by way of both methods on known higher order passive frequency filter structures. Third order low pass filter is here realized and scaled in frequency scope from 100 Hz to 100 MHz.
10

Návrh nových aktivních filtrů pomocí grafů signálových toků / Design of new active filters, using signal flow graphs

Jašek, František January 2010 (has links)
This master’s thesis describes the design of the frequency filters by the help of the graph of the signal flows. There are defined by modern components like GVC (Generalized Voltage Conveyor), GCC (Generalized Current Conveyor), CF (Current Follower), DO-CF (Dual-Output Current Follower), OTA (Operational Transconductance Amplifier), BOTA (Ballanced Operational Transconductance Amplifier) and CFTA (Current Follower Transconductance Amplifier), the graphs of the signal flows, which describe their activity in the thesis. In the other part of the thesis is illustrated the procedure of the design of the frequency filters by the help of the graphs of the signal flows. For the concrete design was selected in the first case as the active component double output current follower and in the second case the CFTA. There are noted all designed circuits of the frequency filters also their characteristic equations in this thesis. The activity of the selected circuits was remitted to the analysis in the simulation program called PSpice. Because the active components, with which was engaged in the design of the filter which doesn’t exist in the real form, that is why the UCC, which is sufficing for attestation of the function of the circuit, was used for the simulation. The simulation was implemented in the frequency range 10 Hz to 10 MHz.

Page generated in 0.086 seconds