Parametric amplifiers are essential for analyzing and measuring the weak signals generated byquantum circuits at cryogenic temperatures. This project aims to realize a low noise travelingwave parametric amplifier (TWPA) by exploiting the nonlinear current dependence of thekinetic inductance of superconducting NbTiN nanowires. We fabricate an inductor in theform of a compact meandering nanostructure on small chips. We describe the microwavecircuit design, the simulations performed and the fabrication recipes. We present the resultsfrom the initial measurements at low-temperature (4.2 K - 0.3 K) performed in a 3He dipstickcryostat.We analyzed two different structures in this thesis. The first design implements a co-planarwaveguide structure that operates as a multi-modal cavity with resonances that can be modifiedby adjusting geometrical parameters. In contrast, the second design attempts to eliminate theseresonances by matching the impedance of the device with that of the input and output signallines. For this reason, we adopted a microstrip structure with a top-layered ground plane.In addition, the second design allows for phase matching of the signal and idler frequenciesinvolved in parametric amplification through dispersion engineering. Finally, we determineimportant parameters like the temperature dependence of the kinetic inductance, phase velocity,and characteristic impedance of the devices at cryogenic temperatures. / Parametriska förstärkare är viktiga för att analysera och mäta svaga signalerna som genererasav kvantkretsar vid kryogeniska temperaturer. Detta projekt syftar till att realisera enresande våg parametrisk förstärkare med lågt brus (TWPA) genom att utnyttja det ickelinjäraströmberoendet hos den kinetiska induktansen i supraledande NbTiN- nanotrådar. Vitillverkar en spole i form av en kompakt slingrande nanostruktur på små chips. Vibeskriver mikrovågskretsdesignen, simuleringarna som utförs samt tillverkningsprocesserna.Vi presenterar resultaten från de initiala mätningarna vid låga temperaturer (4.2 K - 0.3 K)utförda i en 3He stickkryostat.Vi analyserade två olika strukturer i detta arbete. Den första designen implementerar enkoplanar vågledarstruktur som fungerar som en multimodal kavitet med resonanser som kanmodifieras genom att justera geometriska parametrar. Däremot syftar den andra designenatt eliminera dessa resonanser genom att matcha enhetens impedans med den för ingångs-och utgångssignallinjerna. Av denna anledning valde vi en mikrostripstruktur med ettjordplan i toppskiktet. Dessutom tillåter den andra designen fasanpassning av signalen ochidlerfrekvenserna som är en del av den parametriska förstärkningen genom dispersionsteknik.Slutligen tar vi reda på viktiga parametrar som temperaturberoendet för den kinetiskainduktansen, fashastigheten och den karakteristiska impedansen för proven vid kryogeniskatemperaturer.

In cancer research, studies on cells are often done in 2D, grown on plates which are not realistic. Therefore, a specialized system is being designed to build 3D cell structures. This system requires a fitting amplifier that is of low cost and changeable gain. The aim of this project was to design, simulate and build a custom amplifier circuit card, PCB, to be used in creating such an amplifier. At the end of the project the custom amplifier PCB should be connected with components such as power supply and should be able to take the place of the current one. The amplifier circuit was designed, and the simulations were tested, a finished design was created. Due to shortage of electronic components, the main IC component could not be acquired and hence a finished circuit could not be built. / Inom cancerforskning görs studier ofta på celler i 2D strukturer, plattor och detta är inte realistiskt. Därför utvecklas det ett nytt sätt att bygga cellstrukturer i 3D. Detta system kräver en anpassad förstärkare av låg kostnad och anpassningsbar förstärkning. Syftet med detta projekt var att bygga ett förstärkarkretskort. Inom metoden gjordes simulering, tester och utveckling av en krets samt bygge av ett förstärkarkretskort. Detta kort skulle kopplas till andra komponenter som nätaggregat och moderkort för att ersätta den nuvarande förstärkare. Simulering och design av krets gjordes men ett färdigt kort kunde inte testas på grund av leveransproblem av elektriska komponenter.

This study was conducted at a special school for children with autism and developmental disabilities. The study consists of three interviews where pedagogues have different experiences of working with children in need of special support. The aim is to get an idea of how teachers think about working with children autism, but above all to find out what methods and educational tools that are used, and why they are used to best motivate students to a rewarding education. Sense of coherence (SOC) is a central concept and a theoretical basis of the study relating to the student to create comprehensibility, manageability and meaningfulness in life. All of these three are essential for the student to find a predictable environment. From the result shows how schools and teachers use different methods and different tools, but both have a focus to help the student find motivation in the learning process. Pedagogues mentions three pedagogical tools where two of them get a little more space in the paper. The pedagogues tell how they think about the various tools and intention of these in the process of helping the student in the quest to find the motivation and meaningfulness in school and life. It is important to highlight the need for special education for children with special needs where special school is an institution that offers expertise in this. Something that makes a big impression is the discussion of how education and training should be tailored along each student's abilities and needs. The pedagogue dialogue is easy to attach to the policy in their operations, curriculum for special school (2011). One pedagogue also expresses this to be a living document which will also serve as support staff in the business.

Usage of class D audio amplifiers has become increasingly widespread in recent years, mainly due to their high efficiency, which can reach almost 100 %. Class D amplifiers can also be compact, making them suitable for mobile applications. In contrast, the most efficient conventional amplifiers such as class B can reach a maximum efficiency of 78.5 %. The high efficiency of class D amplifiers can be attributed to the switching stage, which in the case of a half-bridge design consists of two amplifying MOSFETs. These MOSFETs are never on at the same time, which minimizes the quiescent current and thereby the power losses. The goal of this project was to design, simulate and construct a half-bridge class D audio amplifier. A working amplifier with 80 % efficiency was built, with power losses occuring mainly in the voltage regulators. Simulations of the amplifier corresponded well with the constructed amplifier apart from issues originating from the aforementioned voltage regulation as well as the triangle wave generator. The goal of the project was achieved and the finished amplifier possessed good sound quality and little unwanted noise. To further improve on the design, better voltage regulation, a full-bridge configuration and a feedback loop could be utilized.

We investigate the resonant characteristics of superconducting meandering nanowires to design a nonlinear kinetic inductance traveling-wave parametric amplifier. The devices are patterned out of 15 nm thick NbTiN films. They consist of a coplanar waveguide, that shrinks into 100 nm wide meandering nanowires. For a total kinetic inductance of ∼1 μH, our simulations show that these structures behave as resonators with fundamental mode frequency around 1 GHz and a phase velocity of the signal as low as c/1000. The resonance peaks correspond to the presence of current antinodes within the meandering structure. Samples were fabricated at the Albanova Nanolab facility and measured in a sample-in-vacuum dipstick at 300 mK. Frequency sweeps in the 0.1-10 GHz range confirm the presence of these resonance peaks. In addition, we investigate the current nonlinearity of our devices. Analysis of the temperature dependence of the resonant peaks revealed the critical temperature of the film, TC = 14.0 ± 0.5 K. The dispersion relations showed that the device impedance exceeds the resistance quantum RQ = 6.5 kΩ when close to resonance or below 87 MHz. A second design was realized in order to reduce the device’s characteristic impedance to ≈ 50 Ω. This design, accomodating a micro stripline, embedded a significantly longer nanowire, with a total kinetic inductance ∼10 μH. Measurements showed a dramatically reduced impedance to ≈ 700 Ω, but still not matched to 50 Ω, giving rise to a dense frequency comb of standing modes in the 0-3 GHz bandwidth, with a constant spacing of ≈ 45 MHz. / Vi undersöker egenskaperna hos supraledande slingrande nanotrådar i syfte att designa en ickelinjär kinetisk induktans parametrisk förstärkare. Våra prov är mönstrade ur 15 nm tjocka NbTiN-filmer. De består av en koplanär vågledare som krymper till 100 nm breda slingrande nanotrådar. Med en sammanlagd kinetisk induktans på ∼1 μH visar våra simuleringar att dessa strukturer beter sig som resonatorer med en funda- mental modfrekvens runt 1 GHz och en fashastighet för signalen så låg som c/1000. Resonanserna motsvarar närvaron av strömantinoder inom den slingrande strukturen. Proverna tillverkades i Albanovas Nanolab och mättes i en prov-i-vakuum-sticka runt 300 mK. Frekvenssvepen i området 0,1-10 GHz bekräftar förekomsten av dessa res- onanser. Dessutom undersökte vi den strömberoende ickelinjäriteten i våra enheter. Analys av resonansernas temperaturberoende ger ett värde på filmens kritiska temper- atur, TC = 14.0 ± 0.5 K. Dispersionsförhållandena visade att provens impedans över- stiger resistanskvantumet RQ = 6, 5 kΩ nära resonanserna. En andra design realiserades för att reducera provens karakteristiska impedans till ≈ 50 Ω. Denna design, med en mikrostripline, har en betydligt längre totaltsträcka med en sammanlagd kinetisk induk- tans på ∼10 μH. Mätningarna visade en dramatiskt reducerad impedans på ≈ 700 Ω, men inte till det matchade värdet på 50 Ω, vilket gav upphov till en tät frekvenskam inom bandbredden 0- 3 GHz, med ett avstånd på ≈ 45 MHz mellan resonanserna.

Modern wireless communication techniques employed in the Wi-Fi® protocol, such as orthogonal frequency-division multiplexing exhibit analogue signals with high peak-to-average power ratio. Therefore, power amplifiers for Wi-Fi suffer from low efficiency when operating in back-off mode, away from their maximum efficiency at peak power. In recent years, digital power amplifiers have been developed to replace their analogue equivalent, taking advantage of easier scaling and circumventing transition frequency issues. Since the digital power amplifier technology for Wi-Fi application is recent, it has not yet replaced robust analogue amplifiers in industrial context. This work proposes to investigate the feasibility and complexity to replace an analogue amplifier with its digital counterpart, with at least the same specification. Among several possible architectures, the reverse class D is chosen for its apparent simplicity. It achieves low power loss into transistors parasitics by operating in square-current mode instead of voltage mode, hence displaying a current-based RF-DAC behaviour. After elaborating the core design with simple efficiency enhancement techniques specific to reverse class D, the layout of the circuitry has been designed. Post-layout simulations have shown the reverse class D digital amplifier designed in CMOS 22nm achieves the required specification of 18dBm average output power with -28dB error vector magnitude in the 2.4GHz range. This basic architecture achieves 19% average drain efficiency, a small improvement over its analogue equivalent currently in use. / Moderna trådlösa kommunikationstekniker som används i Wi-Fi®-protokollet, till exempel ortogonal frekvensdelningsmultiplexering, uppvisar analoga signaler med hög variation i amplitud. Därför har effektförstärkare för Wi-Fi låg verkningsgrad eftersom de arbetar i back-off-läge, långt ifrån sin maximala verkningsgrad vid hög uteffekt. Under de senaste åren har digitala effektförstärkare utvecklats för att byta ut deras analoga motsvarigheter. Eftersom digitala effektförstärkare för Wi-Fi är nya, har de ännu inte ersatt robusta analoga förstärkare i industriella sammanhang. I detta arbete föreslås en undersökning av genomförbarheten och komplexiteten i att ersätta en analog förstärkare med dess digitala motsvarighet, med åtminstone samma specifikation. Bland flera möjliga arkitekturer har den strömbaserade klass D valts på grund av sin enkelhet. Den uppnår låg effektförlust i transistorparasiter genom att arbeta i strömsläge istället för i spänningsläge, och fungerar som en strömbaserade RF-DAC. Efter att ha utarbetat kärnkonstruktionen med enkla tekniker för effektivitetsförbättring som är specifika för strömbaserade klass D har kretsens layout utformats. Simuleringar efter layouten har visat att den digitala förstärkaren i strömbaserade klass D som konstruerats i CMOS 22nm uppnår den nödvändiga specifikationen på 18 dBm genomsnittlig uteffekt med -28 dB felvektorstorlek vid 2,4 GHz. Denna arkitektur uppnår en genomsnittlig verkningsgrad på 19%, vilket är en liten förbättring jämfört med den analoga motsvarighet som för nuvarande används.

This project has been done as a part of a bachelors degree in engineering at Uppsala university. The project was supervised by Jörgen Olsson at the division of solid state electronics. The goal of this project was to develop a distortion effect that can be used with an guitar and a amplifier. The effect was to have controllable distorsion, volume and tone control including bass and treble. The circuit is also supposed to be run using a 9V battery as power supply, which means that the in circuit currents shold be low. When the circuit was finished it was also analyzed through different measurements and simulations. The distortion of the circuit was achieved using diodes to get a nonlinear amplification. The goals of the circuit controls was achieved, and although a low circuit current was achieved, it only satisfied the goal of 1 mA when high distorsion was set for the circuit. When measuring and simulating the system, some major differences was found. The simulated frequency response characteristics was found to be very different from the measured. This is likely due to the simulation program not being

SiC in Space is one of the experiments on KTH’s miniature satellite, MIST. The experiment carries out tests on bipolar junction transistors of silicon and silicon carbide. This thesis describes how the characteristics of a transistor can be measured using analog circuits. The presented circuit design will work as a prototype for the SiC in Space experiment. The prototype measures the base current, the collector current, the base-emitter voltage as well as the temperature of the transistor. This thesis describes how a test circuit may be designed. The selected design has been constructed in incremental steps, with each design choice explained. Different designs have been developed. The designs have been verified with simulations. We have also constructed and tested three different prototypes on breadboards and printed circuit boards. / SiC in Space är ett av experimenten på KTHs miniatyrsatellit, MIST. Experimentet utför test på bipolära transistorer av kisel och kiselkarbid. Detta examensarbete förklarar hur transistorns karakteristik kan mätas med analoga kretsar. Den framtagna kretsdesignen kommer att fungera som en prototyp till SiC in Space-experimentet. Prototypen mäter basströmmen, kollektorströmmen, bas-emitter-spänningen samt temperaturen för transistorn. Detta examensarbete förklarar hur en testkrets kan designas. Den valda designen byggs i inkrementella steg, där varje designval förklaras. Olika designer har utvecklats. Designerna har verifierats genom simuleringar. Vi har också konstruerat och testat tre olika prototyper på kopplingsdäck och kretskort.

Increased awareness concerning our energy consumption and its environmentaleffects, has led to a high demand for renewable energies. Hydropower providesaround 40 percent of the electric energy consumed in Sweden today. If energyefficiency and production time were to increase only by some percent in thehydropower plants, vast amounts of additional renewable energy could besupplied to the electric grid. The Hydropower group at Uppsala University usesa hydropower generator to localize and decrease some of the power losses andthe wearing in the generator. New equipment is being tested and evaluated onthe generator. By measuring static and dynamic forces in the generator broaderinsight can be reached during these tests. This thesis describes the development of a system measuring forces on ahydropower generator using strain gages. Each sensor node is equipped withfour strain gages and a signal conditioning circuit. The system measures strain inthe generator, converts it to a voltage signal, amplifies it, filters and transmits it.After calibration of the nodes, forces can be extracted indirectly. This thesisdescribes considerations made during design of the system as well as its differentparts and configurations.

Trippelnegativ bröstcancer (TNBC) är den mest maligna formen av bröstcancer utan någon framträdande behandlingsbar biomarkör. Således har den djupa återfallsfrekvensen och bristen på behandlingsalternativ öppnat behovet av att förstå TNBC: s etiopatogenes och molekylära mekanism. Huvudsyftet är att kartlägga det genomomfattande differentiella uttrycket av den förmodade cancergenen (en prenyleringsgen) och dess betydelse vid trippelnegativ bröstcancer. Hi-Cap (Capture Hi-C) är en teknik som genererar högupplösta promotor-förstärkare interak- tioner med nästan en-förstärkare upplösning.Vi arbetade med cancercellinjer, MDA-MB_231, med och utan den förmodade genen. Hi-C-tekniken optimerades i enlighet därmed för cancer- cellinjen för att generera en högupplöst berikad region. Resultaten kan vidare användas för att utföra biblioteksförberedelser och bioinformatikanalys. Dessa fynd kommer att ägnas åt att upptäcka nya vägar involverade i prenylering och TNBC. / Triple-negative Breast cancer (TNBC) is the most malignant form of breast cancer with no prominent treatable biomarker. The profound recurrence rate and lack of treatment options have opened the need to understand the etiopathogenesis and molecular mechanism of TNBC. The main objective of this study is to map the genome-wide differential expression of the putative cancer gene (a prenylation gene) and its importance in Triple-Negative Breast cancer. Hi-Cap (Capture Hi-C) is a technique which generates high-resolution promoter-enhancer interactions with almost single-enhancer resolution. We worked with cancer cell lines, MDA-MB_231, with and without the putative gene. The Hi-C technique was optimized accordingly for the cancer cell line to generate a high-resolution enriched region. The results can be further used to perform library prep and bioinformatics analysis. These findings will devote to discovering novel pathways involved with prenylation and TNBC.