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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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Computer modeling of communication systems
Polášek, Jiří ; Vágner, Petr (referee) ; Raida, Zbyněk (advisor)
The thesis will focus on using the program Ansoft Designer, more precisely, its module System Design, during simulation involving communication systems. A few examples show the work with the program on simulating the communication system without coding, and then with coding according to the standard 802.11 (Wi-Fi). The thesis also deals with creating custom blocks communication schemes. Described the creation of blocks and then their test.
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Studies of Influences of Oscillators Frequency Instabilities in Satellite Communication Systems
Baran, Ondřej ; Baláž, Igor (referee) ; Šimša, Jan (referee) ; Kasal, Miroslav (advisor)
The dissertation thesis deals with a study of an influence of a simultaneous incidence of an additive thermal noise and a multiplicative phase noise on the useful signal transmission in narrowband satellite communication systems. While the additive thermal noise affects the useful signal only on the receiver side of the communication system, the multiplicative phase noise is produced in all system oscillators. One investigates how the receiver filter bandwidth reduction takes effect on the influence of individual noise types. The thesis is divided into four units. The first one (chapters 4 and 5) solves the ways of modeling of both noise types. In the second part (chapter 6), on the simple example, the primary analysis of the phase noise influence is made. Basic modulation schemes used in the satellite communication are also discussed (chapter 7). Third part (chapter 8) is devoted to the modeling of a general digital system with a M PSK modulation made directly on the main carrier wave. The last part (chapter 9) describes the modeling of a digital system with a BPSK modulation on the auxiliary subcarrier wave followed by an SSB modulation on the main carrier wave. General conclusions are deduced from obtained simulation results.
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Small-size active integrated antenna
Nunvář, Rostislav ; Pokorný, Michal (referee) ; Raida, Zbyněk (advisor)
Bachelor’s thesis deals with basic types of planar antennas, with the design and simulation in the program ANSOFT Designer. The project is focused on the completion of a planar antenna by an active element (a transistor). The transistor can be integrated into planar structure by the N-Port function of Ansoft Designer. Finally, advantages and disadvantages of passive and active planar antennas are described.
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Multiband antenna design in ANSOFT Designer
Šulc, Ivo ; Řezníček, Zdeněk (referee) ; Raida, Zbyněk (advisor)
The project is focused on modeling multiband planar antennas in the program ANSOFT Designer. First, the methodology of the design and modeling of a patch antenna in ANSOFT Designer is described. Second, four types of multiband planar antennas are analyzed. The planar antenna is chosen in next step which is optimalized and subsequently produced. Finally, the analyzed antennas are mutually compared.
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Modeling and optimization of patch antennas
Šídlová, Ludmila ; Láčík, Jaroslav (referee) ; Raida, Zbyněk (advisor)
This work is engaged in modeling of patch antennas. It describes various types of synthesizing the layout and designing the microstrip feeder or probe feeding. This work is focusing on modeling and creating a patch antenna for 6 GHz fabricated from ARLON 25N and fed by a microstrip. The layout is first calculated from required antenna parameters and substrate parameters. The optimization of the patch antenna is carried out in the program ANSOFT Designer, which analyzes planar structures by the moment method. The fabricated patch antenna is measured by a vector analyzer. Results of measurements and computations are compared in terms of frequency response of the standing wave ratio for the frequency interval from 5.5 to 6.5 GHz. The patch antenna is also modeled in the program COMSOL Multiphysics as a two-dimensional conical monopole with a coaxial feeding, and a three-dimensional patch fed by a microstrip; the design is optimized for the operation frequency 6 GHz.
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Frequency doubling active antenna
Tomíček, Martin ; Černý, Petr (referee) ; Raida, Zbyněk (advisor)
This thesis deals with the analysis of a planar antenna operating at two frequencies with use frequency doubling. The design and simulation of the antenna in ANSOFT Designer is described. The antenna is designed for two operating frequencies 900 MHz and 1.8 GHz. The antenna is required to operate TM10 mode and TM01 modes.
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Planar antenna array for receiving the digital tv signal
Havelka, Michal ; Hertl, Ivo (referee) ; Raida, Zbyněk (advisor)
The master’s thesis deals in first part with the design of a single antenna element of an antenna array for receiving the digital TV. The resonant frequency of the antenna is 4.7 GHz, the antenna operates in the frequency band 4.4 to 5.0 GHz. Properties of the antenna are verified in programs CST Microwave Studio and Ansoft Designer. The final antenna element is experimentally produced. The second part is devoted to microstrip divider, 2x2 elements antenna array and 4x4 elements antenna array. The antenna array 4x4 elements was produced and its properties were measured.
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VSAT Terminal Model
Kudlička, Miroslav ; Ondráš, Radek (referee) ; Baran, Ondřej (advisor)
This work deals with the description of the communication using the VSAT satellite network. A used network topology, frequency bands, satellite orbits and also an access technology are defined. The next part is focused on the VSAT terminal, where the block diagram is shown. A model of the indoor unit IDU is designed in the system background of Ansoft Designer. Individual parts of the system model are analyzed in terms of input variables. The results of the simulation are shown. The curves of BER before Viterbi decoding and after Viterbi decoding are shown too.
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Modeling of planar coupling circuits
Valošek, Josef ; Puskely, Jan (referee) ; Láčík, Jaroslav (advisor)
This master’s thesis deals with modelling of the planar coupling circuits, namely type of the wideband couplers and the ultra-wideband couplers. The purpose of this thesis is an analysis, a synthesis, a numerical modelling and a fabrication (only chosen types) of the presented couplers. All of the couplers works on medium frequency f0 = 7 GHz with coupling C = 3 dB. Types of the substrate are Arlon 25N and Arlon AD600. EM simulator IE3D and circuit simulator in program Ansoft Designer are used for the numerical modelling. The realized wideband couplers were measuring by the vector analyzer Agilent E3864B.
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