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Antennas with metamaterial radomes
Martínek, Luděk ; Tkadlec, Roman (referee) ; Pítra, Kamil (advisor)
This thesis deals with microstrip antennas covered by the metamaterials. First, are described planar antennas, their problems and the emergence of surface waves. Surface waves can cause unwanted coupling among particular parts of the structure and can degrade its parameters. The problem can be solved using an electromagnetic band gap structure (EBG). These periodic structures are able to suppress surface waves in different frequency bands. It is shown how the EBG structure in the function superstate improve directivity and antenna gain. Radiation conventional microstrip antenna with metallo-dielectric EBG superstrate and with the purely dielectric double-layer superstrate is described. The both structures are designed and simulated in CST Microwave Studio program. Further is described the antenna radiation with so-called mushroom structure and metallo-dielectric EBG superstate. The structure is again designed and simulated in CST MWS program. Finally, there are two structures with metallo-dielectric superstate implemented and measured.
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Patch antenna with EBG substrate
Cepek, Tomáš ; Pítra, Kamil (referee) ; Hebelka, Vladimír (advisor)
The aim of the thesis is to describe EBG substrate and exminate his influence on some types of antennas and choose one of them for realization. In first part this thesis describes the paramaeters of antenna in generall, in the second part is dedicated to introduction with EBG substrate mainly on the surface with the high impedance (HIES). The third part deals with the simulations of microstrip patch antennas with EBG substrate and without EBG substrate. In the last parts was designed and optimized antenna using superstrate.
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Synthesis of electromagnetic bandgap structures
Šedý, Michal ; Kovács, Peter (referee) ; Raida, Zbyněk (advisor)
In microwave frequency band, the planar technology is mainly used to fabricate electronic circuits. Propagation of surface waves belongs to the significant problem of this technology. Surface waves can cause unwanted coupling among particular parts of the structure and can degrade its parameters. The problem can be solved using an electromagnetic band gap structure (EBG). These periodic structures are able to suppress surface waves in different frequency bands. This thesis is focused on the modeling of these structures in the program COMSOL Multiphysics.
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Mutual coupling reduction techniques in microstrip patch phased arrays
Horník, Milan ; Pokorný, Michal (referee) ; Mikulášek, Tomáš (advisor)
This thesis deals with the investigation of the mechanisms of the formation of mutual coupling and its suppression between a pair of patches located above the common ground plane. The thesis includes an analysis of mutual coupling formation and a proposal of techniques dealing with its suppression. To analyse the mutual coupling, a pair of patch elements in both polarizations was designed and their mutual coupling was investigated. A suitable variation of the techniques was selected based on a study of the available suppression techniques of mutual coupling. The antenna designed by the selected technique was simulated and later produced. With interest, the suppression technique was used, extended to an 8x1 element array, and the function of a phased antenna array was tested.
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Patch antenna with EBG substrate
Cepek, Tomáš ; Pítra, Kamil (referee) ; Hebelka, Vladimír (advisor)
The aim of the thesis is to describe EBG substrate and exminate his influence on some types of antennas and choose one of them for realization. In first part this thesis describes the paramaeters of antenna in generall, in the second part is dedicated to introduction with EBG substrate mainly on the surface with the high impedance (HIES). The third part deals with the simulations of microstrip patch antennas with EBG substrate and without EBG substrate. In the last parts was designed and optimized antenna using superstrate.
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Antennas with metamaterial radomes
Martínek, Luděk ; Tkadlec, Roman (referee) ; Pítra, Kamil (advisor)
This thesis deals with microstrip antennas covered by the metamaterials. First, are described planar antennas, their problems and the emergence of surface waves. Surface waves can cause unwanted coupling among particular parts of the structure and can degrade its parameters. The problem can be solved using an electromagnetic band gap structure (EBG). These periodic structures are able to suppress surface waves in different frequency bands. It is shown how the EBG structure in the function superstate improve directivity and antenna gain. Radiation conventional microstrip antenna with metallo-dielectric EBG superstrate and with the purely dielectric double-layer superstrate is described. The both structures are designed and simulated in CST Microwave Studio program. Further is described the antenna radiation with so-called mushroom structure and metallo-dielectric EBG superstate. The structure is again designed and simulated in CST MWS program. Finally, there are two structures with metallo-dielectric superstate implemented and measured.
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Synthesis of electromagnetic bandgap structures
Šedý, Michal ; Kovács, Peter (referee) ; Raida, Zbyněk (advisor)
In microwave frequency band, the planar technology is mainly used to fabricate electronic circuits. Propagation of surface waves belongs to the significant problem of this technology. Surface waves can cause unwanted coupling among particular parts of the structure and can degrade its parameters. The problem can be solved using an electromagnetic band gap structure (EBG). These periodic structures are able to suppress surface waves in different frequency bands. This thesis is focused on the modeling of these structures in the program COMSOL Multiphysics.
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