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Antenna for mobile high power microwave generator
Kračmar, Leoš ; Láčík, Jaroslav (referee) ; Mikulášek, Tomáš (advisor)
The bachelor thesis deals with the design and practical implementation of a magnetron connected to waveguide as an excitation source for a linear slot antenna array. The goal was thorough acquaintance with the issue of partial parts of designs, verification of calculated parameters using software simulations and practical measurements on manufactured parts of the project. In the first part of the work, it theoretically deals with used components, used parameters and by software design of a magnetron to waveguide transition model with practical measurement. The second part of the work contains calculations and simulations of the design of a linear slot antenna array, which continues by series of practical measurements of antenna properties.
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Antennas for energy transmission along the car roof
Škoda, Adam ; Hebelka, Vladimír (referee) ; Vélim, Jan (advisor)
The presented master’s thesis deals with antennas transmitting energy along conductive materials. Surface waves are used for energy transmission. According to its properties, the horn antenna was chosen for the problem solution. This thesis includes the theoretical analysis of surface waves, waveguides and horn antennas. The concept of antennas includes the comparison of two different materials and two different frequencies. From the set of 8GHz antennas, the structure of two antennas where one wearing the other was chosen as the most suitable. The FoamClad material was also selected due to achievement of better parameters and properties then material CuClad. This structure was designed by two identical horn antennas where the energy between them is transmitted via slot. The suitable feeding and parallel plates were designed, and further the current structure was modified to SIW structure. The designed antenna was manufactured and its properties were measured for further comparison with simulation results. Furthermore, achieved differences between simulated and real antenna are discussed.
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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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Network for high-frequency on-body communication
Halas, David ; Láčík, Jaroslav (referee) ; Kokolia, Martin (advisor)
This work focuses on the design of a network for high-frequency communication on the human body. The thesis is focused on the design of two-band antennas, namely 2.4 GHz and 5.8 GHz. The antenna is integrated into the textile and works close to the human body. The introduction describes the problem of spreading electromagnetic waves along the human body. Further, the thesis deals with the applicability of different types of antennas for integration on the textile substrate. Based on the simulations performed, a suitable antenna is selected for the purpose. The simulation program used is the CST Microwave Studio. In the end, the antennas were optimized, subsequently manufactured and their parameters measured.
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Antenna system for car radar
Zechmeister, Jaroslav ; Hazdra, Pavel (referee) ; Láčík, Jaroslav (advisor)
This thesis deals with the design of lens antennas for automotive radar in 77 GHz bandwidth. The work explains methods of designing waveguides as well as horn antennas and dielectric lens. A simulation of three designed horn antennas is performed in CST Microwave Studio. Antennas with spherical and hyperbolical lens are simulated as well and subsequently optimized for maximal gain. The thesis also investigates effects of the lens permittivity on its properties. Furthermore, the work deals with a design of an antenna system with minimalized antenna coupling. Nylon, ABS and photopolymer lens are designed and compared afterwards. ABS and photopolymer lens were produced by 3D print
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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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Free space method for measurement of complex permittivity
Nekovář, Jiří ; Hertl, Ivo (referee) ; Láčík, Jaroslav (advisor)
The aim of this thesis is the development of the workplace for the complex permittivity measurement by free space method. At the beginning of this thesis, the method is described. Further attention is focused on the discussions concerning electromagnetic properties of materials, comparison of the methods used for complex permittivity measurement, interactions of planar electromagnetic wave with planar infinite dielectric slab of general environment and description of radiation patterns of microwave antennas. In the rest of the thesis, the measuring workplace for the free space method is designed and fabricated. A pyramidal horn antenna is selected as a radiator. The antenna is designed with coax to waveguide transition in CST Microwave Studio, and than fabricated in two samples and measured. Finally, the fabricated measuring workplace is exploited for the complex permittivity measurement.
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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 optimalization 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 final part of the thesis deals with evaluation of achieved results.
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Double ridge horn antenna for antenna measurement
Vašina, Petr ; Hertl, Ivo (referee) ; Láčík, Jaroslav (advisor)
The thesis deals with broadband antennas for measurement purposes. A ridged horn antenna has been selected for this concept, designed for the frequency range 0.9 GHz to 9 GHz. This work contains general theoretical description of antennas and further it focuses on a specific design of the ridged horn antenna, beginning with the calculation of its dimensions, modeling and optimization to obtain desired antenna properties. Finally, the antenna was constructed and measured. The reflection factor s11
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In-car wireless power transfer
Cupal, Miroslav ; Polívka, Milan (referee) ; Raida, Zbyněk (advisor)
The thesis is focused on the design of antennas for wireless power transfer inside a car near the frequency of 8 GHz. In the last century, a number of scientists dealt with wireless transmission of energy with high power and long distances. Currently, attention is given to methods capable of transmitting energy with good effectively over a distance of meters for charging mobile devices, wireless sensors and other devices with low power consumption.
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