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Multiband magnetic antenna
Ryšánek, Martin ; Hertl, Ivo (referee) ; Raida, Zbyněk (advisor)
The thesis deals with a parametric analysis of a magnetic multiband antenna and explains the principle of its operation. In the thesis, an optimization of the antenna by the particle swarm optimization is performed in order to meet impedance matching in prescribed frequency bands.
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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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Planar antenna array for receiving the digital tv signal
Havelka, Michal ; Hertl, Ivo (referee) ; Raida, Zbyněk (advisor)
The master’s thesis deals in first part with the design of a single antenna element of an antenna array for receiving the digital TV. The resonant frequency of the antenna is 4.7 GHz, the antenna operates in the frequency band 4.4 to 5.0 GHz. Properties of the antenna are verified in programs CST Microwave Studio and Ansoft Designer. The final antenna element is experimentally produced. The second part is devoted to microstrip divider, 2x2 elements antenna array and 4x4 elements antenna array. The antenna array 4x4 elements was produced and its properties were measured.
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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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Improving antenna parameters by the application of metamaterials
Šporik, Vladimír ; Hertl, Ivo (referee) ; Raida, Zbyněk (advisor)
The thesis is focused on the design of a planar resonant-type antenna, which exploits a proper combination of left- and right-handed properties of transmission lines. This transmission line is called CRLH TL and is based on Sievenpiper mushroom structure. Advantages of the proposed antenna concept are demonstrated by a detailed comparison of its basic properties with the properties of a conventional patch antenna.
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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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Multireflector fractal antenna
Mikulka, Josef ; Hertl, Ivo (referee) ; Raida, Zbyněk (advisor)
The project verifies the methodology of the design of multiband antennas with planar reflectors based on frequency selective surfaces. During the design procedure, Zeland IE3D and CST Microwave Studio are compared in detail. The final conclusion is that both the programs produce similar results.
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Rectangular patch atenna for the frequency band 60 GHz
Hubka, Patrik ; Hertl, Ivo (referee) ; Hebelka, Vladimír (advisor)
The goal of this thesis is design and build rectangular patch antenna for 60 GHz band, matched to 50 Ohms. First section described general knowledges about microstrips antennas and technologies for 60 GHz band. Second section introduced rectangular patch antenna feeded by miscrostrip line matched by quarter wave transformer on CuClad 217 substrate. Third section introduced two structural modification of rectangular patch antenna and measurements of return loss |S11|.
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Multireflector fractal antenna
Mikulka, Josef ; Hertl, Ivo (referee) ; Raida, Zbyněk (advisor)
The project verifies the methodology of the design of multiband antennas with planar reflectors based on frequency selective surfaces. During the design procedure, Zeland IE3D and CST Microwave Studio are compared in detail. The final conclusion is that both the programs produce similar results.
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Rectangular patch atenna for the frequency band 60 GHz
Hubka, Patrik ; Hertl, Ivo (referee) ; Hebelka, Vladimír (advisor)
The goal of this thesis is design and build rectangular patch antenna for 60 GHz band, matched to 50 Ohms. First section described general knowledges about microstrips antennas and technologies for 60 GHz band. Second section introduced rectangular patch antenna feeded by miscrostrip line matched by quarter wave transformer on CuClad 217 substrate. Third section introduced two structural modification of rectangular patch antenna and measurements of return loss |S11|.
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