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Shaping of light fields for control and correction of electron beams
Brada, Tomáš ; Bouchal, Petr (referee) ; Hrtoň, Martin (advisor)
Elektrony v elektronovém mikroskopu jsou běžně řízeny statickými elektrickými a magnetickými poli. Existuje však také možnost modifikovat dráhu elektronu skrze ponderomotivní potenciál vytvořený laserovým pulsem. Tato práce se zabývá tvorbou speciálně tvarovaných laserových svazků pro potřeby tohoto zařízení. V první části je vysvětlen princip fungování elektronového mikroskopu řízeného světlem. Následuje přestavení prostorového modulátoru světla, který bude k tvarování svazku využit. Poté je rozebráno hledání fázové masky pro prostorový modulátor, což zahrnuje komentář simulačních metod propagace světla, rešerši iterativních algoritmů pro problém hledání fáze a postup vývoje vlastního algoritmu. Na závěr je vyvinutý algoritmus otestován v experimentu.
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Spatial Division of Optical Beams
Hampl, Martin ; Lazar, Josef (referee) ; Vlček, Čestmír (referee) ; Wilfert, Otakar (advisor)
The dissertation thesis deals with a free space optical links, especially is focused directly to the transmission optical beams. The influence of environmental conditions like atmospheric turbulence, buildings movement and vibration is described. As a possibility to reduce these undesirable influences, the generation of the transmission beam by the help of the two-mode optical fiber is proposed. A possibility to drive the shape of the resulting transmission beam by means of the change of power ration of individual modes in fiber is described. The coherence features of the proposed beam are analyzed considering the possibility to reduce the influence of atmospheric turbulence. In the thesis there are introduced beam quality parameters that enable to evaluate the quality of the optical beam for the free space optical link. These parameters give the relationship between the shape of the optical beam and the power balance of the optical link and the statistical evaluation of the optical link.
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Beam steering antenna
Krejčíř, Dominik ; Pokorný, Michal (referee) ; Mikulášek, Tomáš (advisor)
The master s thesis deals with the design of the beamsteering antenna. Methods of the beamsteering and the final antenna design are described. This antenna operates in the ISM band with the central frequency of 5,8 GHz. The antenna is designed in the CST Studio Suite 2020. Butler matrix was designed as a feed network implemented as substrate integrated waveguide. An array of patch antennas was used for radiation.
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Laser beam shaping
Hantl, Josef ; Dvořák, Filip (referee) ; Hudcová, Lucie (advisor)
Thesis describes shortly types of waves and beams. Gaussian beam properties and parameters are described in more details, Gaussian beam is the most used in atmospheric optical links. The main goal of work is studying of possibilities of laser beam shaping, mainly the beam Top hat. In this project reasons why is suitable to shape laser beam for optical communications and the most used methods for shaping of laser beam are described. The suggested processes of beams shaping are experimentally verified and properties of beams shaped of single methods are compared with each other.
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Radar receiver beamforming implementation in FPGA
Bárta, Jakub ; Dvořák, Vojtěch (referee) ; Bohrn, Marek (advisor)
This thesis deals with design and implementation of digital beamformer for 3D radar. The text of this thesis contains derivation of beamforming algorithm and detailed description of it’s implementation on development kit with Cyclone V circuit. At the end of the thesis the beamformer design is verified and it’s further usage is discused.
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Beam steering antenna
Krejčíř, Dominik ; Pokorný, Michal (referee) ; Mikulášek, Tomáš (advisor)
The master s thesis deals with the design of the beamsteering antenna. Methods of the beamsteering and the final antenna design are described. This antenna operates in the ISM band with the central frequency of 5,8 GHz. The antenna is designed in the CST Studio Suite 2020. Butler matrix was designed as a feed network implemented as substrate integrated waveguide. An array of patch antennas was used for radiation.
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Radar receiver beamforming implementation in FPGA
Bárta, Jakub ; Dvořák, Vojtěch (referee) ; Bohrn, Marek (advisor)
This thesis deals with design and implementation of digital beamformer for 3D radar. The text of this thesis contains derivation of beamforming algorithm and detailed description of it’s implementation on development kit with Cyclone V circuit. At the end of the thesis the beamformer design is verified and it’s further usage is discused.
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Spatial Division of Optical Beams
Hampl, Martin ; Lazar, Josef (referee) ; Vlček, Čestmír (referee) ; Wilfert, Otakar (advisor)
The dissertation thesis deals with a free space optical links, especially is focused directly to the transmission optical beams. The influence of environmental conditions like atmospheric turbulence, buildings movement and vibration is described. As a possibility to reduce these undesirable influences, the generation of the transmission beam by the help of the two-mode optical fiber is proposed. A possibility to drive the shape of the resulting transmission beam by means of the change of power ration of individual modes in fiber is described. The coherence features of the proposed beam are analyzed considering the possibility to reduce the influence of atmospheric turbulence. In the thesis there are introduced beam quality parameters that enable to evaluate the quality of the optical beam for the free space optical link. These parameters give the relationship between the shape of the optical beam and the power balance of the optical link and the statistical evaluation of the optical link.
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