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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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Vivaldi antenna fed by substrate integrated waveguide
Pavlíček, Rostislav ; Puskely, Jan (referee) ; Mikulášek, Tomáš (advisor)
The thesis deals with Vivaldi antenna design fed by substrate integrated waveguide (SIW). The first step in solving is focused on design this antenna in the simulation program Ansoft HFSS, where the antenna parameters are optimized gain, impedance bandwidth and minimizing the size of the side lobes. The result is the implementation of Vivaldi antenna structure SIW and compare the results with simulations. The work includes a comparison of simulated and measured parameters realized antenna.
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Vivaldi antenna fed by substrate integrated waveguide
Pavlíček, Rostislav ; Puskely, Jan (referee) ; Mikulášek, Tomáš (advisor)
The thesis deals with Vivaldi antenna design fed by substrate integrated waveguide (SIW). The first step in solving is focused on design this antenna in the simulation program Ansoft HFSS, where the antenna parameters are optimized gain, impedance bandwidth and minimizing the size of the side lobes. The result is the implementation of Vivaldi antenna structure SIW and compare the results with simulations. The work includes a comparison of simulated and measured parameters realized antenna.
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Slot Antenna Array Based on Substrate Integrated Waveguide
Sedláček, Petr ; Polívka, Milan (referee) ; Mikulášek, Tomáš (advisor)
The Master’s Thesis deals with the design of slot antenna array based on the substrate integrated waveguide (SIW). Various supply methods are described and the design procedure is approached. The antenna array was designed for Wi-Fi band of 5 GHz in the Ansoft HFSS simulation software. The optimalized parameters are impedance bandwidth (low reflection coefficient at antenna input in the desired frequency band) and the gain (the maximum value). As the result of the work 3 antenna arrays based on the substrate integrated waveguide are designed and fabricated: antenna arrays 2x1, 2x2 and antenna array 2x2 supplemented with housing for outdoor use. The work also contains a comparison of simulated and measured parameters of antennas.
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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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Design of device for water jet erosion of materials
Mikulášek, Tomáš ; Kárník, Jan (referee) ; Rudolf, Pavel (advisor)
The aim of this diploma thesis was to design experimental setup for planar samples erosion by means of the water jet on the rotational sample configuration, laboratory experimental testing and its evaluation by means of the 3D optodigital microscope Olympus DSX 510. There were observed typical erosion patterns at the solid tested material surfaces as well as the cavitation erosion. Experiments were carried out at the following water pressures: 0.432 MPa, 1.50 MPa on the rotating sample, at 2.50 MPa on steady sample and on flooded sample for different treatment times. Experimental results of waterjet impact on rotating sample were compared with the theoretical modelling data obtained by CFD modelling. Computational modelling was done in two parts: 3D modelling of water jet flow impact on rigid steady surface and 3D modelling of water jet impact on rigid moving surface. The latter modelling was solved as two phase modelling, where the computational model “Volume of Fluid” was employed. The aim of the study was to find out for the individual cases under study appearance of the water flow and the changes of the magnitude of the force of the impinging water jet on the wall.
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Dualband Antenna for Global Navigation Satellite System
Mikulášek, Tomáš ; Lukeš, Zbyněk (referee) ; Láčík, Jaroslav (advisor)
This master’s thesis introduces to the reader with a modern antenna type the microstrip patch antennas. The most common types of microstrip antennas and their parameters and feeding methods are introduced in the theoretical section of this master’s thesis. This section deals with the circularly polarized microstrip antennas. Design of an active dual-band circularly polarized antenna for global navigation satellite application in the AWR Microwave Office is presented in the practical section. The proposed single-fed dual-band circularly polarized design is achieved using two stacked square microstrip patches. The antenna operates at the L1 + E1 and L5 + E5a frequency bands. Antenna preamplifier consists of a low-noise transistor and a dual-band band-pass filter. The thesis describes realization and measurement results of the dual-band antenna performance in the anechoic chamber. Measured results of the preamplifier performance are presented.
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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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Dynamometer for measuring power of IC-engines
Mikulášek, Tomáš ; Klimeš, Lubomír (referee) ; Štětina, Josef (advisor)
The aim of the work was to summarize the development of a system for measuring the power of internal combustion engines, from the initial simple dynamometers, to modern electronic devices with flange strain gauge for sensing torque compared their advantages and disadvantages, usability, efficiency, performance and manageability. Furthermore there was performed comparison with the standards dealing with this issue. Use of these devices is available, subject to atmospheric conditions specified in standard and manufacturer.
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