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Magnetic loop antenna with electronic tuning for frequencies below 30MHz
Burda, Miroslav ; Vágner, Petr (referee) ; Urbanec, Tomáš (advisor)
This project deals with electronic tuning and automated adjustment of magnetic loop antennas, working in the High Frequencys. The whole work is divided into three parts tuning, adjustment and control). The tuning part is realized by changing the capacity of the array capacitors and adjustment is done by different changes of power points. The whole system is controlled by a microprocessor ATmega16. According to utility switches the microprocessor capacity, which tunes the antenna to the required frequency, processes information about power adjustment and autimatically fine-tuning the antenna by changing the position of charging.
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Subharmonic Mixers for Microwave Bands
Kintr, Jindřich ; Frydrych, Jiří (referee) ; Urbanec, Tomáš (advisor)
The task of this master’s thesis is design and implementation subharmonic mixer for the microwave band. Subharmonic mixer is based on the principle of antiparallel diode. In the first two parts are theoretically described mixers (subharmonic mixer) and topology suitable for implementation. Another work describes the design subharmonic mixer. The proposal is implemented in the program Ansoft designer. DPS is created in Eagle or in Ansoft Designer. The mixer is designed and implemented first on the lower frequency and consequently at higher frequencies (24,048 GHz and 47,088 GHz). Work also includes the measurement results of the mixer.
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Power amplifier for 435MHz Band with High Efficiency
Herceg, Erik ; Špaček, Jiří (referee) ; Urbanec, Tomáš (advisor)
This diploma thesis is focused on design of high frequency power amplifiers in UHF band, specifically at 435 MHz. Amplifiers are designed in different classes of operation. The thesis deals with the comparison of main parameters in each class of operation, the most important parameter is effeciency. The amplifying part is unipolar transistor which is working in Single-stage mode. The results were simulated in Advanced Design Systems Software.
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Selective Circuits - Laboratory Experiment
Košťál, Stanislav ; Vágner, Petr (referee) ; Urbanec, Tomáš (advisor)
The aim of this thesis is to describe the distribution and behavior of selective circuits and methods for their implementation. There are formulas provided for the calculation of the frequency components of selected second-order RLC filters. It further describes the choice of filter frequency components and computing relationships needed for the construction of coils. The work also includes a description and complete information needed for making measurements of the measurement of the RLC band-pass. The annex to this work includes all the materials needed for implementation of laboratory tasks designed to measure using the product.
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Magnetic Loop Antenna with Electronic Tuning for Frequencies below 30MHz
Svoboda, Luděk ; Vágner, Petr (referee) ; Urbanec, Tomáš (advisor)
The aim of this bachelor's project was realization of a tuning system with complete software and testing of the system's functionality and parameters of antenna. The system is divided into two parts, tuner and controller. The tuner implements change of circuit capacity by switching capacitor series. For switching is used transistor with small transitional capacity but small maximal collector current, too. This parameter restricts the use of system. The second part, controller, uses microcontroller AT89C2051. The microcontroller switches capacitors (and thus sets frequency) according to requests sent from PC with control software. The functionality was checked by tests with network analyzer.
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BPSK transmitter for 435 MHz
Hocz, Jan ; Šebesta, Jiří (referee) ; Urbanec, Tomáš (advisor)
This thesis deals with basics of BPSK modulation. Another part compares different integrated circuits of transmitters able to use BPSK modulation on a given frequency, the choice of suitable microprocessor and transistor. Another part describes the connection of individual integrated circuits on printed circuit board and their realization. In the following section, the software and individual commands for transmitter control are described. In the final section is the functionality checked and the basic parameters reached are presented.
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Low noise amplifier for UHF band
Benites Ayala, Ivan Alejandro ; Urbanec, Tomáš (referee) ; Kasal, Miroslav (advisor)
This bachelor’s thesis presents the design of a low noise amplifier for UHF band 430-440MHz. This thesis is mainly focused on stability study and matching networks. For this design is used Ansoft Designer program, through which it is possible to simulate the low noise amplifier. The ATF-54143 transistor is used as main device for this design. Morover, there is designed a band pass filter, which satisfies the requirements for this low noise amplifier.
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Microwave power amplifier
Pecen, Vojtěch ; Urbanec, Tomáš (referee) ; Kasal, Miroslav (advisor)
The goal of this bachelor's thesis is to create a design of a microwave power amplifier working in X-band at the center frequency of 10.368GHz. The amplifier has to operate in CW mode and pulse mode with output power of 36dBm and gain of 20dB. Contents of this bachelor's thesis include a theoretical analysis, design of the amplifier and its bias and protective circuits, simulations of time constants of the bias circuits, simulations of the amplifier, construction and measurement of the amplifier parameters.
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Satellite Telemetry Archive
Vorálek, Jan ; Povalač, Aleš (referee) ; Urbanec, Tomáš (advisor)
This thesis deals with a design of telemetry archive of PSAT, PSAT-2 and BRICSat sattelites. This telemetry data need to be extracted from SDR IQ records. The thesis contains a Doppler effect theory and description of structure of telemetry data. Then it presents a design of a program for Doppler effect correction, demodulation and decoding of these records and saving the data to telemetry archive. Thesis also deals with analysis of decoded data.
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Antenna preamplifier for EMI measurements
Sedlák, Milan ; Urbanec, Tomáš (referee) ; Dřínovský, Jiří (advisor)
The master thesis deals with the design of a low noise preamplifier operating in the frequency range from 30 MHz to 1 GHz, usable for measuring and testing of electromagnetic interference in the electromagnetic compatibility test rooms. The introductory, theoretical, part is focused on the analysis and description of the necessary properties of the low noise preamplifier required for the subsequent design. The practical part deals with the selection of suitable components, simulation, design and subsequent realization of low noise preamplifier. At the end of the thesis the design and the final verification measurements are described and discussed.
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