|
|
ARC oscillator with blocks with variable parameter
Bořecký, Tomáš ; Kolka, Zdeněk (referee) ; Slezák, Josef (advisor)
Within the master’s thesis there is comparison of different structures of ARC oscillators with respect to their harmonic distortion. Individual blocks of oscillator are analyzed. Attention is paid to choosing and design of suitable ARC filter structure and possibilities of its tuning. Also possibilities of stabilization of amplitude are analyzed. Different types of controlled amplifiers and circuits for controlling of their amplification are discussed. Next captures are focused to designing and simulation of the ARC oscillator. The oscillator can be tuned in the frequency range from 100 Hz to 20 kHz with harmonic distortion smaller than 1%. At the end of the thesis, practical realization of the proposed circuit is described. Also results of the measurement of parameters of the oscillator are given.
|
|
|
ARC filter for frequency analyser
Janečka, Martin ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this work is to propose and realization an active frequency filter with a 4th grade bandpass for making it possible to electronically tune the resonant frequency in range of 10Hz to 100kHz and adjust bandwidth. The thesis discussed two possibilities of filter connections using cascade synthesis. To choose a better option a filter simulations were made in Pspice. Based on the simulations, the number of components and the possibility of electronic tuning a better option is selected. This circuit is implemented, measured and then compared with simulations.
|
|
|
Active Frequency Filters for Higher Frequencies
Fröhlich, Lubomír ; Dostál, Tomáš (referee) ; Biolek, Dalibor (referee) ; Sedláček, Jiří (advisor)
This thesis deals with the synthesis and optimization of frequency analogue filters with modern active elements usable for higher frequencies. The thesis is divided into three parts, the first part deals with the problematic concerning Leap-Frog combined ARC structure. Due to a difficult design, this method is not described in a detail and used in practice, although it shows e.g. low sensitivity. Firstly, a complete analysis of individual filters was made (for and T endings) and consequently these findings were used during implementation of this method to NAF program. Finally, samples of real filters were realized (for verification of functioning and correct design). Another very interesting topic concerning filters is usage of coupled band-pass for small bandwidth, where it is necessary to solve the problems concerning ratio of building elements values, but also price, quality, size of coils, sensitivity, Q factors, coefficients etc. That is why in practice a coil is very often substituted with other equivalent lossy and lossless blocks which create ARC filters structure. The design and the possibility of usage of lossy grounded elements were described here (such as synthetic inductors, frequency dependent negative resistor). Some parts of the design are individual computer sensitivity analysis, setting of usage and quality comparison of individual lossy grounded blocks. Besides, a program for these elements was created, it is useful for a quick design and depiction of transfer characteristics. The third part deals with the usage of tuning universal filters consisting three or more operational amplifiers, which secures its universality and possibility to create different kinds of transfer characteristic. In practice, Akerberg - Mossberg and Kerwin - Huelsman - Newcomb are the most used types of filters. These were also compared with less common universal filters. In the end, the possibility of digital tuning of universal filter with the help of digital potentiometers for filters of 10th order and frequency around 1 MHz was shown.
|
|
|
ARC filter for frequency analyser
Janečka, Martin ; Murina, Milan (referee) ; Sedláček, Jiří (advisor)
The aim of this work is to propose and realization an active frequency filter with a 4th grade bandpass for making it possible to electronically tune the resonant frequency in range of 10Hz to 100kHz and adjust bandwidth. The thesis discussed two possibilities of filter connections using cascade synthesis. To choose a better option a filter simulations were made in Pspice. Based on the simulations, the number of components and the possibility of electronic tuning a better option is selected. This circuit is implemented, measured and then compared with simulations.
|
|
|
Active Frequency Filters for Higher Frequencies
Fröhlich, Lubomír ; Dostál, Tomáš (referee) ; Biolek, Dalibor (referee) ; Sedláček, Jiří (advisor)
This thesis deals with the synthesis and optimization of frequency analogue filters with modern active elements usable for higher frequencies. The thesis is divided into three parts, the first part deals with the problematic concerning Leap-Frog combined ARC structure. Due to a difficult design, this method is not described in a detail and used in practice, although it shows e.g. low sensitivity. Firstly, a complete analysis of individual filters was made (for and T endings) and consequently these findings were used during implementation of this method to NAF program. Finally, samples of real filters were realized (for verification of functioning and correct design). Another very interesting topic concerning filters is usage of coupled band-pass for small bandwidth, where it is necessary to solve the problems concerning ratio of building elements values, but also price, quality, size of coils, sensitivity, Q factors, coefficients etc. That is why in practice a coil is very often substituted with other equivalent lossy and lossless blocks which create ARC filters structure. The design and the possibility of usage of lossy grounded elements were described here (such as synthetic inductors, frequency dependent negative resistor). Some parts of the design are individual computer sensitivity analysis, setting of usage and quality comparison of individual lossy grounded blocks. Besides, a program for these elements was created, it is useful for a quick design and depiction of transfer characteristics. The third part deals with the usage of tuning universal filters consisting three or more operational amplifiers, which secures its universality and possibility to create different kinds of transfer characteristic. In practice, Akerberg - Mossberg and Kerwin - Huelsman - Newcomb are the most used types of filters. These were also compared with less common universal filters. In the end, the possibility of digital tuning of universal filter with the help of digital potentiometers for filters of 10th order and frequency around 1 MHz was shown.
|
|
|
ARC oscillator with blocks with variable parameter
Bořecký, Tomáš ; Kolka, Zdeněk (referee) ; Slezák, Josef (advisor)
Within the master’s thesis there is comparison of different structures of ARC oscillators with respect to their harmonic distortion. Individual blocks of oscillator are analyzed. Attention is paid to choosing and design of suitable ARC filter structure and possibilities of its tuning. Also possibilities of stabilization of amplitude are analyzed. Different types of controlled amplifiers and circuits for controlling of their amplification are discussed. Next captures are focused to designing and simulation of the ARC oscillator. The oscillator can be tuned in the frequency range from 100 Hz to 20 kHz with harmonic distortion smaller than 1%. At the end of the thesis, practical realization of the proposed circuit is described. Also results of the measurement of parameters of the oscillator are given.
|
guest ::
