|
|
Design of Planar Optical Waveguide
Dvořák, Václav ; Friedl, Martin (referee) ; Nešpor, Dušan (advisor)
This bachelor´s thesis deals with the theoretical fundamentals of planar optical waveguides, possibilities of their fabrication and design of planar optical waveguide. Design of waveguide will be simulated using FDTD Solutions and Ansoft HFSS. These two software use different techniques for computational simulation. The parameters of waveguide will be modified to achieve better performance of waveguide. The result will be compare the properties of waveguides. There will be also described design of implementing waveguide.
|
|
|
Design and Realization of Phantom for MRI
Šablatura, Martin ; Čáp, Martin (referee) ; Nešpor, Dušan (advisor)
Paper studies the principles of MRI and composition of MR system. Main part of thesis focuses on design, mixing and measurement of solution for MR system phantom. Teoretical part of paper focuses on problematic of MRI and phantoms for MR system, including description of specific phantom, which is then realised. Paper contains methods for designing proposed kind of phantom and its followed measurement. Part of paper also focuses on mathematical models of elaboration of data aquired from measurements.
|
|
|
ISM band wireless transmission
Juráň, Jeroným ; Nešpor, Dušan (referee) ; Friedl, Martin (advisor)
This document summarizes the basic possibilities of communication using ISM bands. It also includes extracts from the ČTÚ regulation concerning usage of ISM bands. The theoretical part describes mainly the functions of chosen transmitter and receiver module. Secondly it describes the design and realization of transmitter and receiver devices including the C libraries for basic use, usable distance measurement and example application using developed devices.
|
|
|
Realization of the positioning device for mapping electromagnetic fields
Jozífek, Eduard ; Drexler, Petr (referee) ; Nešpor, Dušan (advisor)
This paper deals with the measurement of electromagnetic fields in reactive zone and proposing an automated workstation for its measurement. The sample is a periodic structure of the circular split resonators, which is due to the magnetic field generated from the supplied loop antenna is brought to resonance and itself becomes imaginary antenna. The measuring probe is placed on the cross-positioning table movement is controlled by two stepper motors.
|
|
|
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.
|
|
|
Design and Realization of the Bird Cage Coil for MRI
Sedlář, Petr ; Drexler, Petr (referee) ; Nešpor, Dušan (advisor)
The work deals with the design and experimental production of the model type Birdcage coil used for magnetic resonance imaging system (MRI). The work deals with the design and behaviour of the model type Birdcage coil volume designed for imaging system for magnetic resonance imaging (MRI). Volume coils are generally very useful for use in MRI, because in transversal design allow easy access into the cavity when the flow vector of magnetization. The aim of the work was to construct a numerical model of transversal coil type Birdcage of the predefined dimensions. The created the coil tuned the desired resonant frequency having regard to maximize performance in the measured sample migrated. The modeling coil experimentally produced and measurements also confirm the accuracy of the numerical model.
|
|
|
A Brief Design of Optical Resonators
Hubík, Daniel ; Nešpor, Dušan (referee) ; Kadlec, Radim (advisor)
This bachelor thesis is focused on analysis of split-ring resonators in THz region. Simulations were made by finite elements method and by finite-difference time-domain method. At first we created a resonating structure that works in GHz region. Then we were observing a dependence of movement of resonant frequency on the size of resonator. In the final chapter we assigned frequency dependent values of permitivity to such structure. As the result we simulated working resonator at frequency 500THz. All simulations have been made in program HFSS ANSYS and Lumerical FDTD Solutions.
|
|
|
Numerical Modeling of Periodical Structures
Nešpor, Dušan ; Bartušek, Karel (referee) ; Brančík, Lubomír (referee) ; Fiala, Pavel (advisor)
The thesis discusses the dynamic electromagnetic field on periodic structures. The author focuses on three principal types of resonant structures, considering their application possibilities. In general, these types can be individually defined as follows: materials exhibiting a negative refractive index of the incident electromagnetic wave; structures with gradual changes in impedance, characterised by their usability as reflectionless surfaces; and periodic structures able to conveniently shape the magnetic field distribution. Materials of the third group within the above-shown short list facilitate the fabrication of magnetoinductive lenses for nuclear magnetic resonance. The presented analysis of the properties of periodic resonant structures is mainly based on numerical models utilising the finite element method, and this approach is combined with both the derivation of the corresponding analytical relations and an experimental measurement of the non-radiating component of the electromagnetic field. The thesis includes a physical description of the basic elements of periodic resonant structures. Physical properties of the elements were examined in detail via numerical analysis. In the course of the research, the data acquired through this analysis and the related experimental measurement enabled the author to propose a method for optimising the most widely used resonant structures. Moreover, several new versions of resonant elements, structures, and fabrication techniques were also designed. The results obtained from the numerical analyses carried out to examine the central physical properties of the fabricated structure samples were all verified via the designed method for measuring the non-radiating component of the magnetic field.
|
|
| |
|
|
Modern methods for Chip Attach
Nešpor, Dušan ; Novotný, Marek (referee) ; Szendiuch, Ivan (advisor)
The work deals with packaging and die attach issues. The general aim of this investigation is thermomechanical stress between package and substrate depending on different thermal and mechanical properties of used materials. Work contains modeling with program ANSYS and practical tests with testing packages. Determining a place in the solder with the maximal and the minimal stress values and determining of the stress distribution for all materials are the results of this research.
|
guest ::
