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PC Controlled PLL Synthesizer
Málek, Miroslav ; Šrámek, Petr (referee) ; Vágner, Petr (advisor)
The aim of this bachelor´s thesis is a practical realization of computer controlled PLL synthesizer using USB serial port. FT232RL was used as an interface between the PLL synthesizer ADF4110 and PC. A software with graphical user interface was also developed in order to control registers of the syntesizer.
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Frequency synthesizer for microwave communication systems
Klapil, Filip ; Vondra, Vlastimil (referee) ; Kasal, Miroslav (advisor)
The main aim of the thesis is to develop a solution of a frequency synthesizer for a microwave communication systems. Specifically, it suggests a design for frequency synthesizer with phase-locked loop. At beginning of the thesis the principle and basic properties of this method of signal generation are explained. Then it is followed by a brief discussion of the parameters of synthesizers and their influence on design. Another part of the work is the analysis of circuit the frequency synthesizer with the phase-locked loop MAX2871, which is followed by a proposal for the design of the frequency synthesizer module hardware. The last part of the work deals with practical implementation, verification of function and measurement of achieved parameters and their evaluation.
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Controll Module for Circuits with ADF4360 and Selected DDS
Lambor, Jiří ; Vágner, Petr (referee) ; Urbanec, Tomáš (advisor)
This bachelor’s thesis is focused on issues of communication between microprocessor unit and frequency synthesizer circuits - direct digital synthesis circuit (DDS), voltage control oscillator with phase lock loop (ADF). The basic theoretical function of DDS, ADF and SPI interface is described in the introduction. The solution and drafts of modules hardware are shown in next chapter. Last chapter describes programming of DDS and ADF circuits with examples of this code in C language. Schemes and board layouts of modules are attached in appendix.
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Software defined transceiver for radio amateur use
Paus, Anton ; Povalač, Karel (referee) ; Žalud, Václav (referee) ; Šrámek, Petr (advisor)
This project deals with possibilities of using the software defined radio conception for radio amateur use in a short wave band and its subsequent implementation into properly designed hardware. The aim of this work is to design a transceiver that would be capable of working in AM, FM, SSB, and CW modes. Within a theoretical part of the project the architectures of software defined radios and their components are discussed. This part was focused mainly on analog parts of the chain, such as amplifiers, filters and converters. Signal processing algorithms for both receiver and transmitter working in desired modes are studied subsequently and their computer models are built. Designed algorithms are implemented into FPGA structure (Virtex -5).
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FM Transmitter of APRS Telemetry in 144MHz Band
Sabol, Martin ; Špaček, Jiří (referee) ; Urbanec, Tomáš (advisor)
This work deals with analysis of protocol APRS Automatic Positioning System for telemetry. There is analyzed the structure of the most important frames and their application. It discusses the processing of GPS data and subsequent modulation of the selected frequency. This work also describes and discusses the proposed peripheral devices and the used firmware.
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Transmitter for professional microphone
Árva, Gábor ; Kubíček, Michal (referee) ; Kolouch, Jaromír (advisor)
This project deals with the design of a transmitter in a wireless microphone system, which connects to a microphone through an XLR connector. It contains detailed description of the individual blocks, which are necessary for processing and transmitting the signal received from the microphone. It discusses methods of frequency modulation using a phase locked loop and compares their advantages and disadvantages. As the last, it deals with the antenna selection and its shrinking methods.
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Zero-Cross Detection for Time Synchronization in the Environment of PLC Communication
Šťastný, Ladislav ; Steinbauer, Miloslav (referee) ; Vozňák, Miroslav (referee) ; Fiedler, Petr (advisor)
The doctoral thesis proposes a synchronization event detection method suitable for establishing a common time base across devices using power-line communication. The technique facilitates the creation of a synchronization procedure for smart grid terminal devices, thus bringing to the low-voltage segment new functionalities already known from the higher voltage levels of the distribution network. High-precision, zero-cross line voltage detection was employed as the synchronization event. The use of the PLL (phase-locked loop) was considered and analyzed as a potentially applicable option; however, such a solution proved to be insufficiently robust against interference. Further, an FFT-based approach was designed and reviewed. The technique performs zero-cross detection, but only for the fundamental harmonic component that remains the same across the entire network. The influence of incoherent sampling on the FFT, too, was tested during the development of the method; in this context, coherent sampling was found to constitute an essential prerequisite for accurate detection as it allows us to eliminate the spectral leakage error. The impact of an AD converter on the detection accuracy was also evaluated. The proposed approach ensures the accuracy required for all common measurements and operations to improve the production, distribution, and consumption of electricity through smart grids.
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Microprocessor control unit with frequency synthesizer for SW radiostation
Povalač, Aleš ; Fuchs, Michal (referee) ; Šebesta, Jiří (advisor)
The thesis is focused on the development of a radioamateur short-wave transceiver. The basic functions, features and parameters are described in the introduction. The bandplan and appropriate types of emission are also included in the introductory part. The frequency synthesis module is discussed in the second part of the document. Emphasis is placed on the direct digital synthesis method (DDS) using modern Analog Devices circuits. The proposed DDS module includes a high-speed clock source. The description of an intermediate frequency module with a demodulator is also placed there. The final part in devoted to the design of a transceiver control panel with a graphical display, a keyboard and a rotary encoder. The firmware for an ATmega128 microcontroller is described in detail at the end of the thesis.
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Concept of three-phase active rectifier
Bareš, Jiří ; Pazdera, Ivo (referee) ; Huták, Petr (advisor)
This work deals with three-phase active rectifier control. In first, theoretical part it describes several control strategies with focus on voltage oriented control. For this type of control a design is worked out, and created model and its simulation is described. Second, practical part deals with realisation on microcontroller TMS320F28335, which is main processing unit of device lent by company Elcom. Therefore in this part abilities and settings of the controller along with developped control algorithm are described. Reached results of measurement are then presented and in the conclusion they are evaluated.
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