The problems of solar cells are described in general in theoretic part of the master’s thesis. In particular there is described structure of solar cells, procedure of production of solar cells, kinds of defects that can occur in solar cells and diagnostic methods of detection of this defects. The solar simulator, electroluminescence method, detection of defects during microplasma shining, LBIV and LBIC method belongs to category of diagnostic methods. The main focusing is on diagnostic method of LBIC (Light Beam Inducted Current). The workplace which exploits this method is used in laboratory in Department of Electrotechnology on University of Technology Brno. This method is very exact and it reveals most of defects in solar cell but the problem is the slow speed of testing. In practical part of the master’s thesis the main solved problem is the proposition and realization of modified workplace of LBIC that would work on more modern level, it means using performer PC for service program and Agilent 34410A the modern measuring device. The speed up of the testing time is the goal of modernization in existing accuracy of finding. The modify workplace is realized and compared with the existing workplace subsequently.

This thesis deals with the use of active components in nonlinear circuits. First the variants of the current and voltage conveyors are theoretically described. Then the thesis deals with the design of the new curcuit structures with nonlinear components, which comes out from the former known realizations. Several possible solutions of the examined circuit have been designed and the most convenient structure has been selected. The chosen solution has been thoroughly analysed in subsequent diploma thesis to enable comparison of the theoretically designed circuit with the practically realized one.

The diploma thesis deals with design of the converter card for the precise control of a laser diode. At first, there are described the principles of the laser diode, photodiode and basic functions of optical fiber sensors. Following chapter deals with description of developed converter card. In the diploma thesis are discussed all function blocks of the converter card and they are explained in detail. In the thesis are subsequently tested all problem parts of the converter card for the precise control of the laser diode, such as fast switching of the current flowing through the laser diode and design of the connection for evaluating of current pulse from the sensing photodiode. An integral part of thesis is a description of created printed circuit board and there are described all used layers and devices’ layout on the PCB. Final part of the diploma thesis deals with firmware for the microcontroller, which was made for testing of all function blocks of the converter card for the precise control of a laser diode. At the same time was developed software for PC, which communicates with the converter card via universal serial bus (USB).

This work deals with the laser diode soldering. The theoretical part summarizes general and acquired findings about soldering technology and materials that occur in this process. It also describes factors that affect the reliability of solder joints. It is closely focused to the shaping of the solder joint and structure of intermetallic layer. The practical part of this work is focused on the design of equipment for laser diode soldering and subsequent shaping of the samples. The quality of soldered joint is compared against the quality of joint created using re-flow technology - remelting in in-line smelter. The structure and thickness of the intermetallic layer, the number and shape of the voids in the solder joints are compared.

This work is focused on description how the light impact human live, description of light sources and finally design and construction of light source with adjustable colour temperature and luminous flux. In introduction is mentioned the process of vision and how the light impact humans. In next part is characterization of currently used light sources, their construction, properties, benefits and drawback with their main parameters. Important part of this chapter is more extensive description of light emitting diodes with their operational parameters. The last two parts is focused on design and measuring the parameters of created light source with adjustable colour temperature and luminous flux and evaluating the results.

Produkce hyperpolarizovaných plynů, především helia (3He) nebo xenonu (129Xe), nachází stále rostoucí rozsah aplikací v zobrazování magnetickou rezonancí (MRI). Helium ani xenon nejsou obyčejně obsaženy v těle a experimenty tedy nejsou ovlivněny nechtěným signálem z okolních tkání. Ukázalo se, že několika hyperpolarizačními technikami může být magnetická polarizace (magnetizace) jader vzácných plynů zvýšena na hladinu, se kterou jsou praktické aplikace proveditelné. Hyperpolarizované plyny mohou tedy být užitečným nástrojem pro neinvazivní zkoumání lidského dýchání, dovolující statické zobrazování během zadržení dechu nebo zkoumání dynamiky výdechu nebo nádechu, nebo funkčního zobrazování. V neživé přírodě, mohou být hyperpolarizovaný plyny využity jako kontrastní látka při studiu mikroporézních materiálů, jako jsou zeolity, stavební látky a hmoty, atd. V této doktorské práci je popsán vývoj a konstrukce aparatury pro hyperpolarizaci xenonu (izotopu 129Xe). Nákup hyperpolarizovaného xenonu od jiných výzkumných center v zahraničí a jeho dovážení by ovšem nebylo efektivní a to zejména z důvodu náročnosti zajištění potřebných fyzikálních podmínek pro přepravu hyperpolarizovaného plynu. Toto bylo hlavní motivací k vývoji vlastní technologie pro přípravu hyperpolarizovaného xenonu. Se zvládnutou technologií by bylo možné navázat spolupráci s medicínskými zařízeními, nebo s týmy zabývající se živou nebo neživou přírodou (např. při studiu mikroporézních materiálů, gelů, v zemědělských aplikacích nebo při výzkumu využívajících zvířat, atd.). Cílem této práce je studium teorie hyperpolarizovaných vzácných plynů se zaměřením na 129Xe a experimentální ověření a změření relaxačních časů pomocí jaderné magnetické rezonance. Vzhledem k tomu, že je možné hyperpolarizované vzácné plyny skladovat pro pozdější využití, se tato práce také zabývá možnostmi zásobníku hyperpolarizovaného vzácného plynu a jeho teoretickým a experimentálním řešením. V této práci jsou popsány především dva základní typy experimentů přípravy hyperpolarizovaného xenonu. V obou jsou využity zatavené válcové skleněné vzorky naplněné xenonem a doplňujícím plynem – dusíkem, heliem. První z experimentů se zabývá měřením vlastností termálně polarizovaného xenonu a druhý měřením vlastností hyperpolarizovaného xenonu. Pro hyperpolarizaci 129Xe bylo použito výkonového laseru a experimentálně byla zkoumána jednak míra polarizace na základě změny spektrální hustoty čerpacího laserového svazku a dále pak optimální doba optického čerpání 129Xe a relaxační časy xenonu.

This thesis deals with the design of an antenna array for the MSPS Radar L band application. The introduction covers a research for a suitable antenna element which can be used as an element of steerable antenna array. The control of the main beam is enabled in the vertical plane. Based on a presented theory, a slotted waveguide antenna array with an omnidirectional radiation in the vertical plane is designed. The operating frequency is set to 1 367.5 MHz. Slotted array achieves 20° width of the main beam in elevation plane. The achieved gain of the array is 9.15 dBi. Further attention of this work is focused on the beam steering that is allowed by diode switching. The last part of the thesis presents manufacturing process of the designed model. The CST Microwave Studio software was used for the antenna array designing process.

<p>U okviru doktorske disertacije predstavljene su elektronska i fononska struktura odabranih organometalnih materijala koji u svom sastavu imaju metale cink, kobalt ili bakar i organsko jedinjenje piridoksalaminogvanidin (PLAG). Predstavljene su realizacija i karakteristike organske svetleće diode zasnovane na najboljem od ispitivanih materijala. Urađena je detaljna analiza fotoluminescentnih spektara i njihovo razlaganje na proste komponente koristeći Lorencov model. Izvršeno je poređenje sa od ranije poznatim materijalom koji pokazuje visok stepen luminescencije. S obzirom da istraživanja vezana za organske svetleće diode uzimaju sve veći zamah i da ove diode postaju sve prisutnije u industrijskoj serijskoj proizvodnji, napravljena je detaljna analiza ove tehnologije i mehanizama koji se kriju iza nje. Urađeno je podrobno istraživanje kako na nivou elektrona u datim supstancama, tako i na nivou sloja organske svetleće diode. Na kraju je izvršena analiza rada diode sa integrisanim slojem sa materijalom koji u sebi sadrži cink i PLAG.</p> / <p>In this thesis electronic and phonon structure of specific organometallic<br />materials which have zinc, cobalt, copper metals and organic compound<br />pyridoxalaminoguanidin are presented. Implementation and characteristics of<br />organic light emitting diode based on the best material among examined<br />ones are also showed up. Detailed analysis of photoluminescence spectra<br />was done and its decomposition to its elementar components using<br />Lorentzian multipeak method. Comparison to well-known material that shows<br />high level of luminescence was implemented. In accordance to the fact that<br />research of organic light emitting diodes expands and that these diodes start<br />to be more present in industrial serial production, detailed analysis of this<br />technology and mechanisms behind it are made. Thorough research was<br />done both on electron level in these substances and organic light emitting<br />diode layer level. Finally, analysis of diode operation with integrated layer<br />made of material which includes zinc and pyridoxalaminoguanidin compound<br />is implemented.</p>

This doctoral thesis is focused on problems of modulators based on six-ports. It begins with description of current state of the art of six-ports used like modulators, their transfer functions and SIW technology. A design part of this thesis consists from experimental six-port based on substrate integrated waveguide (SIW) technology. There is presented step-by-step development of this six-port using this technology and also there is introduced micro-strip technology based six-port. Final design of six-ports and variable impedances were measured, the results are discussed and compared with expected ones in next chapters. Second part of this thesis deals with influences of internal parameters of six-ports to final signal transmission and derives theirs transfer functions for more than one reflection in structure. The computation results are compared with experimental measurements for fixed loads. With using of ideal loads sweeps, modulations with shaped input signals were calculated. For designed variables impedances, there was founded the optimal biasing points for demanded IQ diagram and discussed which from tested active circuit is suitable. In the last part there are shown results of experiment with these variable loads connected to both types of designed six-ports.

The purpose of this thesis is proposal of auxiliary power sources in electric traction. Specifically we deal with two converters. Both of them were used in traction vehicle's applications, which are developed by the Department of Power Electrical and Electronic Engineering, Brno University of Technology. First converter was used as a power supply in secondary traction mechanism of electric locomotive. Second one to power supply of dash board in automobile with fuel cells.