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VHF SSB Receiver with Low Consumption
Matoušek, Martin ; Povalač, Aleš (referee) ; Urbanec, Tomáš (advisor)
This work is focused on proposal of SSB receiver operating at 30 MHz. The design was primarily focused on simplicity and low power consumption. This work was realized for the transmission of audio signals. SSB modulation is far more efficient in terms of the radio spectrum used. First part of this thesis describes a block diagram of a receiver. Next parts are focused on proposal of individual blocks of the receiver, especially its most important parts. Finally, the overall evaluations of the design characteristics of SSB receivers are discussed.
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DRM signal transmitter
Paták, Pavel ; Šebesta, Jan (referee) ; Lukeš, Zbyněk (advisor)
Master’s thesis deals with design and practical realisation of electronic circuits, which are needed for assembling of DRM signal transmitter for ham short waves bands. There is presented DRM standard as well as there are described the differencies between DRM for radio broadcast and for ham using. There is described design of input audio circuits, modulator, mixer, local generator, amplifier and filters. Principle of used SSB modulator is based on phase method, often called Tayloe modulator. This principle is analysed in detail including mathematical description, which was derived. It is possible to control the transmitter by program running at computer, communication takes place via USB. There is described establishment of communication in this work too.
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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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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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HF and IF circuits of shortwave radiostation
Šnajdr, Václav ; Vágner, Petr (referee) ; Lukeš, Zbyněk (advisor)
The study, description, design and implementation of selected blocks of multiband shortwave radio station are dealt with in the thesis. Focus is placed on the concept of multiband shortwave radio stations, with an emphasis on high frequency and intermediate frequency circuits. The first chapter is devoted to description of the transceiver block diagram which is designed as superheterodyne. The design of bandpass input filters, intermediate frequency crystal filters and output filters is described. Simulation results and the measured characteristics of the implemented functional blocks are presented. Furthermore, the amplifier circuits which maintain impedance matching of individual blocks are discussed. SSB signal generation in the transmitter part of radio station and final stage power amplification are depicted.
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