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Design and Realization of Metamaterial
Kovaľová, Soňa ; Drexler, Petr (referee) ; Nešpor, Dušan (advisor)
The thesis discusses the design of periodic resonant structures, studying of their impact to surrounding electromagnetic field and realisation of magnetoinductive lens with potential application in nuclear magnetic resonance imaging. Frequency tuning of structure by variation of different parameters is described. The finite element method in Ansys HFSS was used to analyse the properties of designed structures.
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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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Computer modeling of meta-materials
Beran, Jaroslav ; Kovács, Peter (referee) ; Oliva, Lukáš (advisor)
The diploma thesis deals with metamaterial structures. Metamaterials are periodic structures, which have got permittivity or permeability, eventually both parameters, negative. Test is applied on three basic structures: Split Loop Array; Spiral Array a Double Spiral Array. For each structure is made dispersion diagram and are monitored S – parameters. Test is run in Ansoft High Frequency Structure Simulator and CST Microwave Studio software. Are monitored bandgaps and when structure is as left – handed medium or right – handed medium. Results are compared with results in literature.
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Smart Structures with Integrated Piezoelectric Materials
Pinček, Ladislav ; Hrstka, Miroslav (referee) ; Hadaš, Zdeněk (advisor)
Táto práca sa venuje skúmaniu smart materiálových vlastností auxetickej štruktúry s elektromechanickou premenou vyvinutej na VUT. Práca sa postupne v jednotlivých bodoch zaoberá zostavovaním laboratórnych vzoriek smart materiálového systému, experimentálnym vyšetrovaním elektromechanických parametrov, dizajnom modelu a návrhom technických aplikácii. Pre danú štruktúru bolo navrhnutých viacero technických využití. Navrhované technické využitia boli experimentálne alebo simulačne skúmané a bol vyhodnotený potenciál pre ďalší výskum.
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Analysis of an Electromagnetic Wave on the Boundary between Electromagnetic Materials
Kadlec, Radim ; Lazar, Josef (referee) ; Macháč, Jan (referee) ; Kroutilová, Eva (advisor)
The proposed dissertation thesis contains an analysis of conditions on the boundary between layers having varied electromagnetic properties. The research is performed using consistent theoretical derivation of analytical formulas, and the underlying problem is considered also in view of multiple boundaries including the effect of the propagation of electromagnetic waves having different instantaneous speed. The author presents a survey and formulation of the basic characteristics of methods used for electromagnetic wave propagation analysis; in this respect, special emphasis is placed on radial models. The processing of the topic involved the designing and verification (using a set of different, layered planar materials) of algorithms to analyze the electromagnetic field components. The algorithm was assembled to enable simple evaluation of all components of the electromagnetic field in relation to the speed of the wave propagation in a heterogeneous environment. The proposed algorithms are compared by means of different numerical methods for the modelling of electromagnetic waves on the boundary between materials; moreover, electromagnetic field components in common points of the model were also subject to comparison. When in conjunction with tools facilitating the analysis of material response to the source of a continuous signal, the algorithms constitute a supplementary instrument for the design of a layered material. Such design enables the realization of, for example, recoilless plane, recoilless transition between different types of environment, and filters for both optical and radio frequencies.
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Modeling metamaterial microwave resonators
Zvolenský, Tomáš ; Kovács, Peter (referee) ; Raida, Zbyněk (advisor)
Práce je věnována modelování mikrovlnných rezonátorů z metamateriálů (materiálů se záporným indexem lomu). V úvodu je rozebráno, co metamateriály jsou, jak se vytvářejí a které jejich vlastnosti jsou podstatné při návrhu rezonátorů. Následuje návrh planárního rezonátoru z metamateriálů. Pro tento účel byly naprogramovány funkce počítající rozměry jednotlivých součástí struktury. Simulace navržené struktury probíhala v programu Zeland IE3D. Simulované struktury byly optimalizovány s ohledem na požadované kmitočty rezonance. První rezonátor sestával z jedné elementární buňky, druhý ze dvou buněk, naladěných na rozdílné kmitočty. Rezonátory byly vyrobeny a experimentálně byly ověřeny jejich vlastnosti.
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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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Broad-spectrum signal propagation through inhomogeneous medium
Měcháček, Radek ; Drexler, Petr (referee) ; Fiala, Pavel (advisor)
Work is focused on both theoretical knowledge of the electromagnetic field and the specific properties of metamaterials measured. First, be informed about the fundamentals of electromagnetic fields, the issue of periodic structures to the properties required metastructures. Further experimental work is designed to measure the properties of metamaterials. The measurements will be used as harmonic signals and broadband signals in the frequency range 100MHz to 10GHz. In the last part of the proposed work is carried out experimental work and are evaluated some characteristics of the antennas and measurement of the selected sample.
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Smart Structures with Integrated Piezoelectric Materials
Pinček, Ladislav ; Hrstka, Miroslav (referee) ; Hadaš, Zdeněk (advisor)
Táto práca sa venuje skúmaniu smart materiálových vlastností auxetickej štruktúry s elektromechanickou premenou vyvinutej na VUT. Práca sa postupne v jednotlivých bodoch zaoberá zostavovaním laboratórnych vzoriek smart materiálového systému, experimentálnym vyšetrovaním elektromechanických parametrov, dizajnom modelu a návrhom technických aplikácii. Pre danú štruktúru bolo navrhnutých viacero technických využití. Navrhované technické využitia boli experimentálne alebo simulačne skúmané a bol vyhodnotený potenciál pre ďalší výskum.
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