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Low-profile directional antenna
Žúrek, Dan ; Pítra, Kamil (referee) ; Láčík, Jaroslav (advisor)
This diploma thesis deals with a study of low-profile directional antennas, followed by design and optimization of parabolic reflector antenna in centimeter and millimeter band. The first part of this work is focused on the analysis of several kinds of directional antennas, mainly on parabolic reflector and on SIW technology, which will be used for final antenna realization. The next part of this project is about the particular concept of the substrate integrated parabolic antenna for 60 GHz ISM band, its simulation and optimization in the CST Microwave Studio software. The final part of this thesis is devoted to the results achieved.
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SIW-Based Circularly Polarized Antenna Arrays
Špůrek, Jan ; Joler,, Miroslav (referee) ; Mazánek, Miloš (referee) ; Raida, Zbyněk (advisor)
Tato disertační práce prezentuje nový koncept kruhově polarizovaných anténních řad na bázi vlnovodu integrovaného do substrátu. Hlavní devízou konceptu je modularita, kdy je základní stavební blok řady použitelný pro tvorbu komplexnějších řad a tento blok zároveň slouží jako šablona pro návrh komplexnější struktury. Anténní řada byla simulována a experimentálně ověřena pro frekvence 17 a 60 GHz. Na základě dosažených výsledků byla odvozena metodologie pro návrh a identifikovány klíčové oblasti návrhu. Následně práce představuje techniku zvýšení šířky pásma osového poměru kruhově polarizovaných anténních řad pomoci parazitních flíčků, které jsou umístěny nad zářiče v definované vzdálenosti. Anténní řada z první části práce byla použita v simulacích a experimentálním ověření pro frekvence 17 a 60 GHz, kdy byla tato řada rozšířena o parazitní strukturu, přidávajíc další vrstvu modularity do konceptu.
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Textile Microwave Components
Hotovec, Jakub ; Láčík, Jaroslav (referee) ; Vašina, Petr (advisor)
This bachelor thesis is focused on possibilities of designing components integrated on substrate, where substrate is fabric. It contains theoretical information about the SIW structure, measurement of dieletric parameters of three fabrics, design, synthesis and production of waveguide, a three port divider and a band-pass filter on three substrates. For simulation CST Microwave Studio is used
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Half-mode substrate integrated waveguide horn antenna
Černý, Matěj ; Mikulášek, Tomáš (referee) ; Láčík, Jaroslav (advisor)
This thesis is about technology of half-mode substrate integrated waveguide (HMSIW) and options proposal of horn antenna fouden on this technology. Based on gained findings HMSIW horn antenna was modeled in program CST Microwave Studio. Main attention is focused on impact geometrical parameters of antenna on it´s emitting and on reflecting ratio at the entrance of antenna. Achieved gain of main lobe was 6 dBi, which is misalignmented to required direction of angle 30°. Antenna has a working frequency 10 GHz.
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Substrate integrated waveguide filter
Vyskočil, Jiří ; Tkadlec, Roman (referee) ; Láčík, Jaroslav (advisor)
In this thesis is discussed a filter design of a band-pass substrate integrated waveguide filter on the frequency of 5 GHz. It also includes design theory, filter synthesis, filter analysis in the program CST Microwave Studio® and the results of measurement on a vector network analyzer. The analysis results are compared with the measured results. Good agreement between simulated and measured results is observed.
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Design of 3D Vivaldi antenna array for radar applications
Kašpar, Petr ; Pitra,, Kamil (referee) ; Puskely, Jan (advisor)
This master thesis deals with a design of Vivaldi antenna due to its broadband properties suitable for radar applications. The folding of single Vivaldi antenna element into 2D antenna array we achieved required radiation properties. Appropriate design of feeding structure realized by SIW technology we obtained suppression of side lobes and deflection of the main lobe. The work also includes design of 3D Vivaldi antenna array. Modeling, simulation and optimization of antenna array were performed in CST Microwave Studio.
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Circularly polarized SIW cavity-backed microstrip patch antenna
Procházka, Petr ; Láčík, Jaroslav (referee) ; Mikulášek, Tomáš (advisor)
This bachelor thesis deals with a circularly-polarized substrate-integrated-waveguide cavity-backed microstrip patch antenna. The first part dedicates basic theoretical knowledge of microstrip patch antennas such as patch shape, the possibility of its excitation etc. The following part describes the possibilities and adjustments of generating circularly-polarized wave from a microstrip patch antenna for generating circularly-polarized waves and general knowledge about the advantages and application of circularly-polarized wave. The next part deals with a step-by-step design of a proposed antenna. The last part present a comparison of simulated and measured results.
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Modeling of antennas for communication near human body
Hodulák, Lukáš ; Hebelka,, Vladimír (referee) ; Vašina, Petr (advisor)
The bachelor thesis deals with problems of body-centric communications. The thesis also deals with the design of Yagi-Uda antenna with power supply substrate integrated waveguide structure (SIW) with the operating frequency of 60 GHz. The thesis is divided into a description of antennas and body-centric communications, description of Yagi-Uda antenna, types of Yagi-Uda antennas, the substrate integrated waveguide and SIW power divider. Then the thesis deals with selected Yagi-Uda antenna, transition between SIW and rectangular waveguide WR-15, antenna array and simulations in CST Microwave Studio. The last part of the thesis is a proposal itself, measurement and comparison of results measured with simulated ones.
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Radiation efficiency measurements of dielectric resonator antennas using Wheeler method
Sedler, David ; Mikulášek, Tomáš (referee) ; Mrnka, Michal (advisor)
Bachelor thesis discusses the dielectric resonators as antenna elements. This work includes description field rectangular resonators, possible dielectric materials, shapes and feeds, e.g. coaxial probe, microstrip line or substrate integrated waveguide. In project is listed measuring radiation efficiency of antennas in general and method used wheeler cavity. Bachelor thesis contains design of waveguide with proposal of dielectric resonator. Design of the antenna was conducted in software CST Microwave Studio and there are demonstrated results of simulations. Radiation efficiency of the dielectric resonator antenna was measured by the Wheeler method and the efficiency received from the measured gain. The work included the measured results together with a comparison of the measurements of both methods and simulations.
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3D printed directional antenna
Dvořák, Václav ; Horák, Jiří (referee) ; Láčík, Jaroslav (advisor)
This master thesis deals with a study of directional antennas, followed by their design and optimization of horn antenna based on SIW for Ka band (26,5- 40 GHz). The first part of the thesis contains the theoretical analysis of the different types of directional antennas, also the SIW technology is described here. It also describes the 3D printing technology by means of which the final antenna should be made. The next part of this work is about design of horn antenna based on SIW. Simulation and optimization of the antenna will be done using the CST Microwave Studio. The horn antenna was modeled with three different dielectric loads. The horn antenna with an experimental triangular dielectric load was chosen for fabrication. The fabricated antenna has reached almost the whole bandwidth to cover Ka. The antenna gain was 9,38 dBi for 33 GHz frequency.
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