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Permittivity measurement of materials by coax probe
Ryba, Ivan ; Oppl, Ladislav (referee) ; Láčík, Jaroslav (advisor)
This thesis describes possibilities of measuring permittivity of various materials, especially with coaxial probe method. It describes character of measuring method, hardware requirements and how to calculate values from the measured. Objective of this thesis is to design measuring station for measuring permittivity of materials with coaxial probe including calibration set. Code in Matlab is also programmed and whole station is tested with known samples to discuss measurement accuracy.
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Slot antenna
Dvořák, Petr ; Horák, Jiří (referee) ; Láčík, Jaroslav (advisor)
This thesis discusses Slot antennas that are based in gap waveguide technology, which allows them to work with high frequency signals. It contains theoretical findings about antennas and waveguides, which are later used in the design. The practical section of this thesis concentrates on designing a specific gap waveguide for 10 and 24 GHz frequencies, starting with modeling and parameter optimalization. This gap waveguide is then used as a base for slot antenna design. The final antenna is designed for frequency of 10 GHz, for both linear and right-handed circular polarizations. With right-handed circular polarization, the achieved band was approximately 1.41 GHz, while the gain was 7,6 dB.
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Rectifying antenna
Makarov, Vitalii ; Horák, Jiří (referee) ; Láčík, Jaroslav (advisor)
This Master´s thesis describes different methods of wireless transmitting of energy: electromagnetic induction, electrostatic induction, laser radiation, transfer of energy by microwaves. This thesis is focused on wireless transfer of energy by microwaves. The paper describes the individual parts of the rectenna. Comparison of different types of antennas for use in the rectenna was made. In this thesis is described set of requirements for design of rectenna. Was made design of the rectenna and its simulation.
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Slot antenna for X band
Buriánek, František ; Horák, Jiří (referee) ; Láčík, Jaroslav (advisor)
This work familiarizes readers with the issues of slot antennas. It presents design and simulation of slot antenna for X band in CST Microwave Studio program. The simulation procedure is described here, including all the settings required for proper operation of the simulation. Then there is the description of the principle of the Half-Mode Substrate Integrated Waveguide - HMSIW. In the end the designed structure of HMSIW and the slot antenna are assembled and measured. The results of the simulation are compared with the results acquired by measurements. The designed antenna at the frequency 10 GHz achieves the impedance bandwidth 255 MHz, and the gain 8,81 dBi (the simulated values in CST Microwave studio).
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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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Modeling of microwave structures based on SIIG
Teplý, Tomáš ; Horák, Jiří (referee) ; Láčík, Jaroslav (advisor)
Well-known dielectric image guide reach in millimeter-wave interesting results. Compared to a conventional types of lines and waveguides is characterised by low-through loss for frequencies approaching 100 GHz. This work is detail focused to basic characteristics and especially type of perforate highpermitivity substrate for obtain implemented waveguide to dielectric board (SIIG). The work also contains couple suggestions for various transitions from a commonly used lines and waveguides. Simulation results using finite element method is achieved attenuation values below 2 dB, which corresponds to a 2 cm length and include a waveguide itself with a pair of transitions. Finally, this work also designed the production method and SIIG applicatoin in practicle.
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Complex permittivity measurement of materials at microwave frequencies
Polák, Radek ; Hertl, Ivo (referee) ; Láčík, Jaroslav (advisor)
This article describes some methods of measuring complex permitivity in milimeter – wave band, their characteristics, anvatages and disadvantages. Discused are here the reasons for their use in the construction of work place. On the basis these reasons is chosen the best method for practical measurement. That is cavity resonant method. Article contain description of designed measurement system. Whitch is verified by computer simulating of developed model in HFSS Ansoft. Text contain also result of simulations and execute computing of comlex permittivity and tangent loss. In Conclusion is desribed results of practical permittivity measure with realized measurement system.
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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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SFN and MFN networks design in DVB-T
Dostal, Radek ; Láčík, Jaroslav (referee) ; Kratochvíl, Tomáš (advisor)
Bachelor’s thesis is focused on SFN (Single Frequency Network) and MFN (Multi Frequency Network) networks design in digital television broadcasting based on DVB-T standard. First part of the thesis is focused on the theoretical description of the MPEG-2 transport stream and basic parameters of broadcasting network, transmitters and transmission path. In practical part are introduced basic parameters of a software package for broadcast network design in RadioLab, RadioBase and Sítě SFN, and results displayed on the digital terrain map and morphologic map. Within solution of this thesis was created signal coverage model of digital transmitters in entire area of Czech Republic, so called networks no.1-4, according to its status in spring 2008. Next is focused on government order about convert from analog to digital video broadcasting terrestrial.
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Computer modeling of a ridge horn antenna
Lacko, Tomáš ; Lukeš, Zbyněk (referee) ; Láčík, Jaroslav (advisor)
This project includes design and simulation of double ridge horn antenna with frequency range from 1,73 GHz to 14,94 GHz. This work is especially target to calculation proportion of horn for requested gain 20 dB and parameters of double ridge horn antenna. The main aim of project is design of antenna with her computer simulation. Antenna is created and simulated by program CST Microwave Studio.
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