|
|
Frequency Filters with Current Active Elements
Jeřábek, Jan ; Ondráček,, Oldřich (referee) ; Kolka, Zdeněk (referee) ; Vrba, Kamil (advisor)
This doctoral thesis is focused mainly on research of new current active elements and their applications in frequency filters suitable for current-mode. Work is focused on design of new filtering structures suitable for traditional single-ended signal processing and also on structures suitable for fully-differential applications. The thesis contains three designed general conceptions of KHN-type second-order filters. Adjustability of quality factor and pole frequency is provided by controllable current amplifiers that are placed properly in designed structures. Structures also contain second-generation current conveyors, multiple-output current followers, transconductance amplifiers and their fully-differential equivalents. There are lot of possible solutions that could be obtained from general structures, some of them are presented in the work. The thesis also presents several multifunctional and also single-purpose filtering structures of second-order and two variants of n-th order synthetic elements which are suitable to realize higher order filters both in single ended and fully differential type. In each case, functionality of new solutions is verified by simulations and in several cases also by real measurement.
|
|
|
Novel active function blocks and their applications in frequency filters and quadrature oscillators
Herencsár, Norbert ; Zahradník, Pavel (referee) ; Kolka, Zdeněk (referee) ; Lattenberg, Ivo (advisor)
Kmitočtové filtry a sinusoidní oscilátory jsou lineární elektronické obvody, které jsou používány v široké oblasti elektroniky a jsou základními stavebními bloky v analogovém zpracování signálu. V poslední dekádě pro tento účel bylo prezentováno velké množství stavebních funkčních bloků. V letech 2000 a 2006 na Ústavu telekomunikací, VUT v Brně byly definovány univerzální proudový konvejor (UCC) a univerzální napět'ový konvejor (UVC) a vyrobeny ve spolupráci s firmou AMI Semiconductor Czech, Ltd. Ovšem, stále existuje požadavek na vývoj nových aktivních prvků, které nabízejí nové výhody. Hlavní přínos práce proto spočívá v definici dalších původních aktivních stavebních bloků jako jsou differential-input buffered and transconductance amplifier (DBTA), current follower transconductance amplifier (CFTA), z-copy current-controlled current inverting transconductance amplifier (ZC-CCCITA), generalized current follower differential input transconductance amplifier (GCFDITA), voltage gain-controlled modified current-feedback operational amplifier (VGC-MCFOA), a minus-type current-controlled third-generation voltage conveyor (CC-VCIII-). Pomocí navržených aktivních stavebních bloků byly prezentovány původní zapojení fázovacích článků prvního řádu, univerzální filtry druhého řádu, ekvivalenty obvodu typu KHN, inverzní filtry, aktivní simulátory uzemněného induktoru a kvadraturní sinusoidní oscilátory pracující v proudovém, napět'ovém a smíšeném módu. Chování navržených obvodů byla ověřena simulací v prostředí SPICE a ve vybraných případech experimentálním měřením.
|
|
|
Frequency filters with untraditional combination of active elements
Filgas, Jaroslav ; Herencsár, Norbert (referee) ; Jeřábek, Jan (advisor)
The Bachelor’s thesis deals with the theory and designing of analog frequency filters of the second order, which operate in current mode and use the untraditional combination of active elements. The filters are designed by means of the autonomous circuits. Active elements used in the design is Multiple Output Current Follower MO-CF, Digitally Controlled Current Amplifier DACA, Generalized Current Mirror and Inverters GCMI, Balanced Operational Transconductance Amplifier BOTA, Inverting Current Conveyor 1st and 3rd Generation ICCI/ICCIII and Universal Voltage Conveyor UVC. The proposed filters work in current mode and their ideal and real models are verified in the simulation environment OrCad. The thesis is structured into five chapters including the conclusion. The first chapter gives the general characteristics of the frequency filters, types of filter functions, types of filters and general equations. The second chapter is devoted to the theory of the active elements. The third charter is about methods of designing and the fourth includes custom designed filters, including their transfer functions and the results verify their functionality in the simulation environment.
|
|
|
Frequency filter
Suchánek, Tomáš ; Kubánek, David (referee) ; Káňa, Ladislav (advisor)
The main objective of this thesis is to design and implement integration that will be building block for tunable active filters 2nd range of low , high and band pass through the jet structure Sallen - Key. This work first examines the use of different types of frequency filters, the detailed design of the components and selection of a suitable operational amplifiers for participation. Practical part focuses on the production of the finished product, measure its parameters resulting in graphs.In implementing are used software such as simulation programme Micro-cap and layout editor Eagle.
|
|
|
Frequency filters with tunable current amplifier
Jemelík, Lukáš ; Lattenberg, Ivo (referee) ; Jeřábek, Jan (advisor)
The bachelor thesis deals with the designing of active frequency filters of the second – order which are make use of active elements. These filters were designed by means of autonomous circuits. Digitally Controlled Current Amplifier DCCA and Multiple Output Current Follower MO-CF were used as active elements. Designed filters works in current mode. The bachelor thesis is divided into five chapters. In the introductory part there are described general characters of frequency filters, the second part contains the description of the active elements, the third part includes the method of construction high – order filters. In fourth part there are described particular circuitry, their transmission functions and confirmation of their functionality in computer software.
|
|
|
Electronically tunable frequency filters
Štěpán, Radim ; Jeřábek, Jan (referee) ; Herencsár, Norbert (advisor)
This bachelor thesis deals with a proposal of electronically controllable filters by means of modern active elemental parts such as current conveyors, transconduct amplifiers or programmable current amplifiers. The suggestion of new connection of frequency filters uses graphic chart of active and passive elements. In the introduction there is described the survey of signal flow graphs, modern active elements suitable for proposal frequency elements. The procedure of proposal of controllable frequency filter based on set typical formula of designed circuit is demonstrated as an example. On a basis of different modifications the designed circuit is made with various types of active elements. Simulation results of the program PCspice confirmed the proper working of the proposal circuits.
|
|
|
Filters with current mirrors
Kotlán, Petr ; Herencsár, Norbert (referee) ; Lattenberg, Ivo (advisor)
A second-order frequency-selection filters with current amplifier design is shortly shown in this bachelor's thesis. An autonomous circuit was modified to be conform with all rules of functionality of filters. A few version of autonomous circuit are shown i this text. The circuits were simulated by a program Microcap expecially transient and AC analysis. The current amplifier was replaced by a current mirror or more precisely by a current inverter. A direct-current and his relations to suplied harmonic signal were investigated. A deformation of a harmonic signal is unwanted. This deformation is ussualy created by the transistors in nonlinear mode. This current have to have special ratio to the alternating-current. A sixth-order filter was created by cascade connection of three second-order blocks. This more intricated circuit is correct. A correct rate of characteristic due for low-pass, high-pass and band-pass was shown thanks AC analysis.
|
|
|
Active frequency filter using current mode
Paščinský, Jiří ; Dostál, Tomáš (referee) ; Slezák, Josef (advisor)
The aim of this work is design of frequency filter working in current mode. The introduction of the work deals with features and applications of frequency filters. Special attention is paid to the transfer function of the filter. In third chapter different operational modes of electrical circuits and their advantages and disadvantages are discussed. Attention is paid to active blocks suitable for circuits working in current mode. There is description of components AD844 and EL2082 which represent current conveyors of the second generation and are used in the designed filter. The last two chapters deal with design of component values of the frequency filter. The designed circuit was simulated in PSpice and the results were compared with measurments. Also sensitivity and tolerance analysis of the filter were performed.
|
|
|
Design of frequency filters with active current elements
Hort, Jiří ; Jeřábek, Jan (referee) ; Vrba, Kamil (advisor)
This bachelor's thesis deal with designing frequency filters with current active elements. Preamble is devoted to description of basic properties and division of filters. Next part presents some way of designing frequency filter. The element CMI (Current Mirror and Inverter) seems like optimal possible solution for application working in purely current mode. To design purposes serves generalized version GCMI. This thesis describes way of designing the autonomous circuit based on full admitance nets with one and two active elements CMI. Several autonomous circuits with four or five passive elements are derived from every admitance network. Individual autonomous circuits are then presented in chart with their characteristic equation. In conclusion is shown design of selected multifunction frequency filter working in current mode as in voltage mode together with characterization for its various transmission functions.
|
|
| |
guest ::
