Detta examensarbete hade till uppgift att konstruera en S/D-omvandlare och tillhörande reglerkrets för att styra kurskransen i en Viggensimulator. I introduktionskapitlet kommer valda delar att tas upp kring synchrots historia samt i vilka tillämpningar och utföranden det kan nyttjas. Här kan även läsas om bakgrunden till detta examensarbete.  I syftet tas det upp vilka de bidragande orsakerna var till att detta arbete gjordes samt de krav som ställts på det utvecklade systemet. Teoridelen tar upp den nödvändiga kunskapen kring begreppen synchro och resolver samt de mindre kretsar och moduler som ingår i systemet. I detta kapitel kan det även läsas om hur konverteringen från synchrosignal till digital data sker och hur matematiska ekvationer kan användas för konvertering från synchro- till resolverformat. Vidare tas här upp den information och teori bakom mjukvaruutvecklingen som hanterar datat. I metoddelen kan det läsas om hur de olika modulerna konstruerats och hur den bakomliggande teorin implementerats. Här kan ses en systemöversikt samt hur enskilda delar konstruerats och sammanfogats till en helhet. Bland annat kan det läsas om hur amplitudnivåer ”fångas”, kommunikationen mellan A/D och mikroprocessor samt hur systemet är konstruerat för att skicka datapaket med vinkelinformation till den reglerenhet som styr kransen. De resultat som åstadkommits genom implementation och konstruktion av både hårdvara och mjukvara då reglersystemet är i arbete redovisas under resultatdelen. Här visas och beskrivs även att de krav som ställts har uppnåtts. I slutsatsen beskrivs utfallet av projektet och hur det i framtiden kommer att förbättras.

<p>Electrically active point defects in semiconductor materials are important because they strongly affect material properties like effective doping concentration and charge carrier lifetimes. This thesis presents results on point defects introduced by ion implantation in silicon and silicon carbide. The defects have mainly been studied by deep level transient spectroscopy (DLTS) which is a quantitative, electrical characterization method highly suitable for point defect studies. The method is based on measurements of capacitance transients and both standard DLTS and new applications of the technique have been used.</p><p>In silicon, a fundamental understanding of diffusion phenomena, like room-temperature migration of point defects and transient enhanced diffusion (TED), is still incomplete. This thesis presents new results which brings this understanding a step closer. In the implantation-based experimental method used to measure point defect migration at room temperature, it has been difficult to separate the effects of defect migration and ion channeling. For various reasons, the effect of channeling has so far been disregarded in this type of experiments. Here, a very simple method to assess the amount of channeling is presented, and it is shown that channeling dominates in our experiments. It is therefore recommended that this simple test for channeling is included in all such experiments. This thesis also contains a detailed experimental study on the defect distributions of vacancy and interstitial related damage in ion implanted silicon. Experiments show that interstitial related damage is positioned deeper (0.4 um or more) than vacancy related damage. A physical model to explain this is presented. This study is important to the future modeling of transient enhanced diffusion.</p><p>Furthermore, the point defect evolution in low-fluence implanted 4H-SiC is investigated, and a large number of new defect levels has been observed. Many of these levels change or anneal out at temperatures below 300 C, which is not in accordance with the general belief that point defect diffusion in SiC requires high temperatures. This thesis also includes an extensive study on a metastable defect which we have observed for the first time and labeled the M-center. The defect is characterized with respect to DLTS signatures, reconfiguration barriers, kinetics and temperature interval for annealing, carrier capture cross sections, and charge state identification. A detailed configuration diagram for the M-center is presented.</p>

<p>Abstract</p><p>Aim of this project was to analyse signals and try to localize the position of source of sound. It is done</p><p>with three microphones which have 90 degrees angle to each other. Each microphone detects one part</p><p>of the sound wave. The microphones are connected toan ADC which turns signals from analogue to</p><p>digital shape. After that the three signals are transformed to a computer. As known a computer</p><p>receives only digital signals which are the main reason to use the ADC. The signals are analysed by</p><p>computer with help of special softwares. These softwares are LabVIEW and MATLAB which are used</p><p>in this work. This analysis of the signals is divided in two parts. The first part is the FFT-analyse (Fast</p><p>Fourier Transform) of the signal from the microphones. It means that the signals frequency’s domain</p><p>is showed, in other word it shows which frequency components a signal has. Then the result is showed</p><p>online by a function belonging to LabVIEW which is called Web Publish.</p><p>In second part the position of the signal source is determined by cross correlation. The position is</p><p>determined by the difference of time between two signals from same source which are measured by</p><p>cross correlation and you can determine angle by triangulating which is described in report.</p>

Further, a highly selective dry etch process for etching Al on AlN has been developed for the fabrication of MIM, MIS, SAW and BAW test structures for electrical and electroacoustic characterization of the films. A dielectric constant of 10 for AlN and 25 for Ti doped Ta2O5 have been measured. With respect to electroacoustic characterization, BAW measurements gave a longitudinal velocity of 11350 m/s and a TCD of -25ppm/K. AlN thin film test structures on SiO2/Si yielded a SAW velocity of around 5000 m/s, while those on polycrystalline diamond exhibited a SAW velocity of 11800 m/s. The latter results illustrate one of the biggest advantages of thin film SAW technology, namely one can exploit both the piezoelectric properties of the film and the acoustic properties of the substrate and hence devise components with superior performance. The explosive development of personal communications systems, navigation, satellite communications as well as personal computer and data processing systems together with the constant demand for higher speeds and larger bandwidths has driven the fabrication technology to its limits. This in turn necessitates the development of novel functional materials for the fabrication of devices with superior performance and higher capacity at reduced manufacturing costs. This thesis focuses on the synthesis and characterization of such materials for IC and electroacoustic applications. Specifically, AlN thin films as well as Ti doped Ta2O5 thin films have been grown using both RF and pulsed-DC reactive sputter deposition on a variety of substrate materials. AlN is a piezoelectric material and hence its crystallographic structure and film texture are of prime interest, while Ta2O5 is a material with a relatively high dielectric constant. A significant part of the work deals with the optimization of the deposition processes. The latter have been optimized both empirically and theoretically by modeling the reactive sputter process. Subsequently, highly textured AlN thin films have been synthesized and characterized. The films were fully c-axis oriented with a typical value for the FWHM of the (002) rocking curve of 1.6°. In addition, epitaxial AlN films have been grown on sapphire at 500oC with relatively low defect density.

The Cu(In,Ga)Se2-based thin film solar cell is a promising candidate for becoming one of the more important solar cell technologies in the near future. In order to realize such a development a significant reduced production cost of the Cu(In,Ga)Se2 (CIGS) layer is needed. This work shows a possible way towards such a reduction by increasing the deposition rate and decreasing the CIGS thickness with almost maintained device efficiency. Obtaining an improved device performance in CIGS-based solar cells by using an in-depth variation of the band gap has earlier been investigated without any clear conclusions. In this work an extensive experimental study of the beneficial effect of band gap profiling has been performed and firmly based conclusions have been made. For standard CIGS devices the band gap profiling can result in an improved efficiency of around 0.4 % units. This gain is related to improved field-assisted carrier collection. For reduced CIGS thicknesses the importance of a band gap profiling is enhanced, and at a CIGS thickness of 0.5 μm an efficiency gain of 2.5 % units is obtained, resulting in a 13.4 % efficient device. The main reason for the gain is passivation of the back contact, which becomes increasingly detrimental for the device performance as the CIGS thickness is reduced. With an optimized band gap profile the CIGS thickness can be reduced 3-4 times, with almost solely absorption related losses. The potential for increasing the deposition rate of co-evaporated CIGS layers is shown to be large. An increase of up to 10 times compared to commonly used deposition rates is possible with only minor losses in efficiency. By using band gap profiled thin CIGS layers deposited at high rates, the production from a single evaporation system can be increased up 30 times. Such an increase will lead to the needed reduction of the production cost of the complete solar cell module.

Electrically active point defects in semiconductor materials are important because they strongly affect material properties like effective doping concentration and charge carrier lifetimes. This thesis presents results on point defects introduced by ion implantation in silicon and silicon carbide. The defects have mainly been studied by deep level transient spectroscopy (DLTS) which is a quantitative, electrical characterization method highly suitable for point defect studies. The method is based on measurements of capacitance transients and both standard DLTS and new applications of the technique have been used. In silicon, a fundamental understanding of diffusion phenomena, like room-temperature migration of point defects and transient enhanced diffusion (TED), is still incomplete. This thesis presents new results which brings this understanding a step closer. In the implantation-based experimental method used to measure point defect migration at room temperature, it has been difficult to separate the effects of defect migration and ion channeling. For various reasons, the effect of channeling has so far been disregarded in this type of experiments. Here, a very simple method to assess the amount of channeling is presented, and it is shown that channeling dominates in our experiments. It is therefore recommended that this simple test for channeling is included in all such experiments. This thesis also contains a detailed experimental study on the defect distributions of vacancy and interstitial related damage in ion implanted silicon. Experiments show that interstitial related damage is positioned deeper (0.4 um or more) than vacancy related damage. A physical model to explain this is presented. This study is important to the future modeling of transient enhanced diffusion. Furthermore, the point defect evolution in low-fluence implanted 4H-SiC is investigated, and a large number of new defect levels has been observed. Many of these levels change or anneal out at temperatures below 300 C, which is not in accordance with the general belief that point defect diffusion in SiC requires high temperatures. This thesis also includes an extensive study on a metastable defect which we have observed for the first time and labeled the M-center. The defect is characterized with respect to DLTS signatures, reconfiguration barriers, kinetics and temperature interval for annealing, carrier capture cross sections, and charge state identification. A detailed configuration diagram for the M-center is presented. / QC 20101028

Abstract Aim of this project was to analyse signals and try to localize the position of source of sound. It is done with three microphones which have 90 degrees angle to each other. Each microphone detects one part of the sound wave. The microphones are connected toan ADC which turns signals from analogue to digital shape. After that the three signals are transformed to a computer. As known a computer receives only digital signals which are the main reason to use the ADC. The signals are analysed by computer with help of special softwares. These softwares are LabVIEW and MATLAB which are used in this work. This analysis of the signals is divided in two parts. The first part is the FFT-analyse (Fast Fourier Transform) of the signal from the microphones. It means that the signals frequency’s domain is showed, in other word it shows which frequency components a signal has. Then the result is showed online by a function belonging to LabVIEW which is called Web Publish. In second part the position of the signal source is determined by cross correlation. The position is determined by the difference of time between two signals from same source which are measured by cross correlation and you can determine angle by triangulating which is described in report.

<p>Effektförstärkare för radiofrekvensapplikationer utgör fortfarande ett av de största problemen i trådlösa kommunikationssystem. Detta beror på att dessa förstärkare är ickelinjära, har låg energieffektivitet och ger mycket distortioner. Bättre verktyg för att förstå och korrigera dessa beteenden är nödvändiga. Ett sådant verktyg är beteendemodellering. En beteendemodell kan ses som en svart låda med insignal(er) och utsignal(er). In detta fall är dessa signaler samplade basbandssignaler och den svarta lådan är en matematisk relation mellan en insignal och en utsignal.</p><p>Avhandlingen behandlar några krav för beteendemodellering av nämnda system genom att presentera metoder för utvärdering och förbättring av modellernas prestanda. Detta åstadkoms genom att betrakta ett frekvensviktat felkriterium. Ett högpresterande mätsystem är också nödvändigt för experimenten. Prestandan hos det tillgängliga systemet jämförs med prestandan hos ett allmänt erkänt mätsystem, en s.k. storsignalsnätverksanalysator, genom att betrakta prestandan hos beteendemodellerna som extraheras och valideras med data från respektive mätsystem. Resultatet visar att det existerande mätsystemet har god prestanda.</p><p>Ett stort problem vid beteendemodellering är att kunna sampla med tillräckligt hög hastighet. Genom att använda Zhu-Franks generaliserade samplingsteorem vid beteendemodellering kan en del av detta problem undvikas. Teoremet medför att man kan sampla med en väsentligt lägre samlingsfrekvens än vad Nyquistteoremet säger. Modeller extraheras och prestandan utvärderas genom att använda kriteriet normalized mean square error (NMSE).</p><p>För stabil prediktion och korrektion av utsignalen måste robustheten hos de använda modellerna verifieras. En sådan studie som berör robustheten mot variationer i lastimpedansen har genomförts. Prestandan på direkta modeller försämras med 7 dB mätt som adjacent channel error power ratio (ACEPR). Prestanda på inversmodellen, implementerad som digital predistortion, försämras med upp till 13 dB mätt som adjacent channel power ratio (ACPR).</p> / <p>Radio frequency (RF) power amplifiers (PA) are still the most troublesomepart of a wireless system due to their inherent nonlinearity, low powerefficiency and high distortions. Better tools are needed to understand and correct the undesirable behavior. Some of these tools are behavioral models. A behavioral model is often thought of as a black box with some inputs andsome outputs. In the case here these inputs are sampled signals which meansthat the modeling amounts to finding a mathematical relationship betweenthe input signal(s) and the output signal(s).</p><p>This thesis considers some requirements for behavioral modeling of said systems by presenting methods for general performance evaluation and improvement by considering a frequency weighted error criterion.</p><p>A high performance measurement system is also needed. The performance of the available system is compared to the performance of a well recognized system, the largesignal network analyzer (LSNA). The results show that the existing measurementsystem can extract behavioral models with the same performance as the LSNA and can give lower performance validation errors.</p><p>Still the need for higher bandwidths drives the measurement systems to the limits, especially the digital parts. By utilizing the so called Zhu-Frank generalized sampling theorem, behavioral modeling of a PA is done by using data acquired at a sampling rate lower than the Nyquist rate. Models of a PA are extracted and the performance is evaluated using the normalized meansquare error (NMSE) criterion. For prediction and correction of the output signals the stability of the models regarding changes must be investigated. One such study considering controlled variations on the output load of the PA is done and both the predictive and corrective capabilities of the models are evaluated. The predictive capability gets up to 7 dB worse measured as adjacent channel error powerratio (ACEPR) and the corrective, as digital predistortion, gets up to 13 dB worse measured as adjacent channel power ratio (ACPR).</p>

<p>In line with the quality awareness of good prevention of pressure sores and in treatment of those sores already developed, evaluation of antidecubitus mattresses plays an important role. However, there are shortages in the evaluations performed today, since often interface pressure is the only parameter regarded. Since ischaemia in the tissue is the primary cause of pressure sore, the focus in this thesis is on blood flow measurements in tissue exposed external loading. To study the tissue blood flow would give a better and more direct indication on the mattress effectiveness in minimizing the negative effects on the tissue viability.</p><p>The results presented in this thesis reveal that the superficial blood flow in areas prone to pressure sore development, is affected by increased skin temperature and external loading of the tissue. Both the effects from pressure and shear stress have been studied.</p><p>Measurements of the tissue blood flow is interesting to relate to the two theories about at which tissue layer the pressure sores start to develop. To achieved more knowledge about the pressure sore etiology and also be able to non-invasively measure the tissue blood flow for evaluations of antidecubitus mattresses an optical sensor has been developed. The sensor combines the two optical methods, laser Doppler flowmetry and photoplethysmography. With the design of the sensor, measurements of the superficial skin blood flow and the deeper blood flow, even the muscle blood flow, can be performed. Measurement depths of 2 mm, 8 mm, and 20 mm into the tissue is assumed.</p><p>Preliminary result from measurements performed with the optical sensor in four test subjects, revealed great individual differences in blood flow, but also different response to the same external loading at different measurement depths, in the same individual. This new optical sensor is likely to be of great value in future studies of pressure sore etiology and in future evaluations of antidecubitus mattresses.</p>

<p>In this thesis, digit-serial implementation of recursive digital filters is considered. The theories presented can be applied to any recursive digital filter, and in this thesis we study the lossless discrete integrator (LDI) allpass filter. A brief introduction regarding suppression of limit cycles at finite wordlength conditions is given, and an extended stability region, where the second-order LDI allpass filter is free from quantization limit cycles, is presented.</p><p>The realization of digit-serial processing elements, i.e., digit-serial adders and multipliers, is studied. A new digit-serial hybrid adder (DSHA) is presented. The adder can be pipelined to the bit level with a short arithmetic critical path, which makes it well suited when implementing high-throughput recursive digital filters.</p><p>Two digit-serial multipliers which can be pipelined to the bit level are considered. It is concluded that a digit-serial/parallelmultiplier based on shift-accumulation(DSAAM) is a good candidate when implementing recursive digital systems, mainly due to low latency. Furthermore, our study shows that low latency will lead to higher throughput and lower power consumption.</p><p>Scheduling of recursive digit-serial algorithms is studied. It is concluded that implementation issues such as latency and arithmetic critical path are usually required before scheduling considerations can be made. Cyclic scheduling using digit-serial arithmetics is also considered. It is shown that digit-serial cyclic scheduling is very attractive for high-throughput implementations.</p>