|
|
Design of a New Structure of an Active Filter on Transistor Level
Michalička, Filip ; Dvořák, Jan (referee) ; Bečková, Zuzana (advisor)
Bachelor's thesis deals with designs of new structures of active frequency filters which operate in voltage mode using active element designed on transistor level. The first part describes parameters and kinds of basic frequency filters and types of aproximation. The second part contains a briefing of unipolar transistors, MOS transistor and his properties. The next part deals with method of signal flow graphs and describes the topology of leap-frog frequency filters. Practical part shows transistor based design of an operational transconductance amplifier using transistors TSMC 0,18 µm from the Taiwan Semiconductor company and designs of two new structures of frequency filters using leap-frog topology. Last part presents schematic diagrams from simulation programms. Verification the function of the operational transconductance amplifier and analysis of the new filter structures is performed by simulation programms OrCAD Capture and PSPICE.
|
|
|
Fully-Differential Frequency Filters with Modern Active Elements
Langhammer, Lukáš ; Dostál, Tomáš (referee) ; Štork, Milan (referee) ; Jeřábek, Jan (advisor)
Tato disertační práce se zaměřuje na výzkum v oblasti frekvenčních filtrů. Hlavním cílem je navrhnout a analyzovat plně diferenční kmitočtové filtry pracující v proudovém módu a využívající moderní aktivní prvky. Prezentované filtry jsou navrženy za použití proudových sledovačů, operačních transkonduktančních zesilovačů, plně diferenčních proudových zesilovačů a transrezistančních zesilovačů. Návrh se zaměřuje na možnost řídit některý z typických parametrů filtru pomocí řiditelných aktivních prvků, které jsou vhodně umístněny do obvodové struktury. Jednotlivé prezentované filtry jsou navrženy v nediferenční a diferenční verzi. Velký důraz je věnován srovnání plně diferenčních struktur s jejich odpovídajícími nediferenčními formami. Funkčnost jednotlivých návrhů je ověřena simulacemi a v některých případech i experimentálním měřením.
|
|
| |
|
| |
|
| |
|
|
Proposal of the fractal order filtering structures
Uher, Jiří ; Dvořák, Jan (referee) ; Langhammer, Lukáš (advisor)
This thesis deals with the fractional (1+)-order filters. The proposed filters operate in the current-mode. The derivation of the filters has been achieved using a third-order aproximation of the coresponding fractional-order transfer functions. It also describes active elements such as universal current conveyor, current follower and operational transconductance amplifier. In the end of this thesis some new circuit solutions of the fractional-order filter are proposed. Then the proposed filters are realized and experimentally measured.
|
|
|
Electronically tunable oscillators
Polanský, David ; Šotner, Roman (referee) ; Petržela, Jiří (advisor)
The goal of bacheolor’s project introduce the reader to the basic principles of oscillator with a possibility of coherent electrical tunning frequency. Project is focused on utilization of non-standard active elements like OTA and CCII. A few wiring circuits are listed, in which it's tunning scale is calculated in PSpise program. Next these devices are compared.
|
|
|
Nonlinear circuits using current active elements
Langhammer, Lukáš ; Kubánek, David (referee) ; Koton, Jaroslav (advisor)
This thesis deals with non-linear curcuit structures with current active elements. In its introduction this work deals with a description of the current active elements, such as current conveyor, transconductance operational amplifier and current follower. Further the text pays attention to the possiblities of the circuits for modification signals in analogue technology. First are described circuits of diode limiters and transducer. Great attention is paid to the amplifiers with current active elements. Are propřed simulated and practically realized circuits of universal precise full-wave rectifiers using operational amplifier and current conveyor and made comparisons of known and proposed circuits. The paper also discussed other circuit structures using of current active elements, such as multiplier, divider, a triangular signal generator and oscillators.
|
|
| |
|
|
Oscillators RC for higher frequency range
Polách, Petr ; Petržela, Jiří (referee) ; Dostál, Tomáš (advisor)
This thesis deals with RC oscillators applicable in higher frequency ranges with the use of modern active elements. For individual function blocks (conveyor, current feedback amplifier, operational transconductance amplifier, voltage feedback amplifier) suitable models are suggested for the circuit simulator PSpice covering their characteristics on various levels, from an ideal one up to the full description of parasitic effects. On the basis of the study of recommended literature and company documentation various oscillator connections of the ranks 2 and 3 are suggested. By analysis through computer (PSpice, SNAP) the fulfilment of oscillation conditions, onset of oscillations were verified and by means of suitable simulations the effects of the impact on the parasitic characteristics of active elements was examined. Finally there are two oscillator connections stated and verified by simulations with the possibility of electronic retuning.
|
guest ::
