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  • 251.
    Andersson Ersman, Peter
    et al.
    RISE Acreo AB, Dept Printed Elect, Norrköping, Sweden.
    Westerberg, David
    RISE Acreo AB, Dept Printed Elect, Norrköping, Sweden.
    Tu, Deyu
    Linköpings universitet, Institutionen för systemteknik, Informationskodning. Linköpings universitet, Tekniska fakulteten.
    Nilsson, Marie
    RISE Acreo AB, Dept Printed Elect, Norrköping, Sweden.
    Åhlin, Jessica
    RISE Acreo AB, Dept Printed Elect, Norrköping, Sweden.
    Eveborn, Annelie
    RISE Acreo AB, Dept Printed Elect, Norrköping, Sweden.
    Lagerlöf, Axel
    RISE Acreo AB, Dept Printed Elect, Norrköping, Sweden.
    Nilsson, David
    RISE Acreo AB, Dept Printed Elect, Norrköping, Sweden.
    Sandberg, Mats
    RISE Acreo AB, Dept Printed Elect, Norrköping, Sweden.
    Norberg, Petronella
    RISE Acreo AB, Dept Printed Elect, Norrköping, Sweden.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Laboratoriet för organisk elektronik. Linköpings universitet, Tekniska fakulteten.
    Forchheimer, Robert
    Linköpings universitet, Institutionen för systemteknik, Informationskodning. Linköpings universitet, Tekniska fakulteten. RISE SICS East, Sweden.
    Gustafsson, Göran
    RISE Acreo AB, Dept Printed Elect, Norrköping, Sweden.
    Screen printed digital circuits based on vertical organic electrochemical transistors2017Ingår i: Flexible and Printed Electronics, ISSN 2058-8585, Vol. 2, nr 4, artikel-id 045008Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Vertical organic electrochemical transistors (OECTs) have been manufactured solely using screen printing. The OECTs are based on PEDOT:PSS (poly(3,4-ethylenedioxythiophene) doped with poly (styrene sulfonic acid)), which defines the active material for both the transistor channel and the gate electrode. The resulting vertical OECT devices and circuits exhibit low-voltage operation, relatively fast switching, small footprint and high manufacturing yield; the last three parameters are explained by the reliance of the transistor configuration on a robust structure in which the electrolyte vertically bridges the bottom channel and the top gate electrode. Two different architectures of the vertical OECT have been manufactured, characterized and evaluated in parallel throughout this report. In addition to the experimental work, SPICE models enabling simulations of standalone OECTs and OECT-based circuits have been developed. Our findings may pave the way for fully integrated, low-voltage operating and printed signal processing systems integrated with e.g. printed batteries, solar cells, sensors and communication interfaces. Such technology can then serve a low-cost base technology for the internet of things, smart packaging and home diagnostics applications.

  • 252.
    Andersson, Gustav
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Energiteknik.
    Ericsson, Emil
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Energiteknik.
    Dark Ages Interferometer (DALI) Deployment Rover: Energy System2014Självständigt arbete på grundnivå (högskoleexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I kosmologi kallas epoken mellan “rekombinationen till väte” och bildandet av de första stjärnorna för “den mörka tidsåldern”. Från denna tid finns endast spår i form av strålning från neutralt väte. Denna strålning kan enligt astronomer vara en viktigare källa till data om universums uppkomst än den kosmiska mikrovågsstrålningen. Därför arbetar NASA/JPL med att hitta metoder att observera denna rika källa till data. Den mest använda metoden är att använda lågfrekventa radioteleskop för att observera strålning med våglängder mellan 3-30 m och frekvenser mellan 10-100 Mhz. Ett stort problem med så kort strålning är den lätt störs ut av mänsklig påverkan och andra radiokällor, tillexempel solen. Ett sätt att undvika antropogen störning är att bygga ett radioteleskop på månens baksida. Eftersom månen är i en låst bana runt jorden vänder den alltid samma sida bort från planeten. Därför är platsen alltid i radioskugga från jorden ochstörs inte av mänsklighetens radiotrafik. JPL har lång erfarenhet av användandet av robotfarkoster för att utforska himlakroppar. År 2030 vill de sända en så kallad rover för att upprätta en grupp radioteleskop på månen med syftet att införskaffa data om “den mörka tidsåldern.” Högskolan i Halmstad erbjuder sedan 2013 studenter möjligheten att skriva sitt examensarbete i samarbete med NASA/JPL om konstruktionen av denna rover. Detta arbete har ämnat finna en lösning på rovens energiförsörjning genom att använda solceller och batterier. Slutsatsen har varit att det är möjligt att driva en rover på månen med solceller samt batterier. Ett krav är att rovern värms med radioisotoperunder natten för att minska energianvändningen.

  • 253.
    Andersson, Göran
    Karlstads universitet, Institutionen för informationsteknologi.
    Synchronized Clock2007Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats
    Abstract [en]

    For this project I was planning to construct a clock that could be synchronized with an external source. The clock should be able to keep the time between synchronizations as these may be sparse. It also needed to be able to store the current time in a memory and keep a register of stored times. The current time and the register must be viewable by the user and the clock must also have the ability to count down the last five seconds prior to a minute selected by the user. I have performed this work at home with my own equipments.

    As an external source for the synchronization I have chosen the DCF-77 clock signal broadcasted from Germany. To receive this signal I used a cheap AM receiver built specifically for this purpose. For the actual clock I used a PIC microcontroller which I programmed in C. The chip had all I needed including an oscillator and a RAM memory. I also connected a 3x16 character LCD display to the clock as well as 4 1-pole buttons for the user interface.

    The program is built upon an interrupt routine that with help of an internal timer is set to execute once every hundreds of a second. During this interrupt routine all other functions are executed. These functions include a DCF decoder, an internal clock to keep the time, an LCD driver and a user interface.

    I have managed to read the clock signal from the receiver but due to interferences from the computer I used to program the PIC chip, I have not been able to get any good reception close to the computer. Apart from this setback the clock works as it should and it meets all other criteria.

  • 254.
    Andersson, Göran
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Kommunikationssystem, CoS.
    Ilic, Marija D.
    Madani, Vahid
    Novosel, Damir
    Network Systems Engineering for Meeting the Energy and Environmental Dream2011Ingår i: Proceedings of the IEEE, ISSN 0018-9219, E-ISSN 1558-2256, Vol. 99, nr 1, s. 7-14Artikel i tidskrift (Refereegranskat)
  • 255.
    Andersson, Henrik
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Öhlund, Thomas
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Manuilskiy, Anatoliy
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Forsberg, Sven
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för naturvetenskap, teknik och matematik.
    Örtegren, Jonas
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Nilsson, Hans-Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    Evaluation of InkAid surface treatment to enhance print quality of ANP silver nano-particle ink on plastic substrates2010Ingår i: Large Area, Organic & Printed Electronics (LOPE-C) 2010, Frankfurt, 2010, s. 241-245Konferensbidrag (Refereegranskat)
  • 256. Andersson, Hjalmar
    et al.
    Zdansky Cottle, Leo
    Claesson, Melker
    Karlsson, Nils
    Stenhammar, Oscar
    Insamling av drift- och produktionsdata från energiteknik vid Ihus anläggning på Vaksala-Eke2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    För att minska den globala uppvärmningen bär utbyggnaden av förnybar energiproduktion en stor vikt i dagens samhälle. Av den anledningen är det av stor betydelse som nya tekniker för energiproduktion testas. För att undersöka huruvida dessa tekniker är effektiva och lönsamma är det viktigt att deras produktionsdata publiceras och görs tillgänglig för allmänheten. Det är anledningen till att det här projektet beställts från Ihus via STUNS energi.

    Projektidén var att samla in högfrekvent uppmätt produktionsdata från en soltracker, ett vindkraftverk och ett batterilager. Dessutom skulle väderdata samlas från en väderstation och solinstrålningsmätare för att sedan offentliggöra datan via STUNS Energiportal.

    För genomförandet av projektet användes en enklare dator för att ta emot information från olika sensorer. För att kommunicera med enheterna användes olika standardiserade kommunikationsprotokoll. Enheterna konfigurerades och kopplades in i datorn. Den insamlade datan bearbetades med en programmerad kod. Programmet sände iväg datan till en molnlagringsplattform för att sedan publicera den.

    Uppkoppling mot soltrackerns växelriktare samt pyranometern lyckades. Den insamlade informationen från de två enheterna publicerades sedan på Energiportalen. Väderstationen producerade data men kommunikation med det ursprungligt tänkta protokollet lyckades inte att upprättas. Genom ett annat protokoll erhölls värden, men inte genom den implementerade koden. Dessutom uppstod problem med batterilagret och vindkraftverket. Ingen information lyckades hämtas från någon av dem.

    I projektets gång har det samlats in mätpunkter var femte sekund för respektive enhet. Utifrån det erhållna resultatet kan de konstateras att vid högfrekvent insamling av väder- och produktionsdata, blir viktig information tydligare för vardera energiproduktionsenhet. Denna information kan gå förlorad vid lågfrekvent datainsamling. Det beror på vädrets hastiga fluktuation. En lågfrekventare datainsamling ger således en sämre uppfattning av hur värdena egentligen ändras med tiden.

  • 257.
    Andersson, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för informationsteknologi och medier.
    3D Video Playback: A modular cross-platform GPU-based approach for flexible multi-view 3D video rendering2010Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The evolution of depth‐perception visualization technologies, emerging format standardization work and research within the field of multi‐view 3D video and imagery addresses the need for flexible 3D video visualization. The wide variety of available 3D‐display types and visualization techniques for multi‐view video, as well as the high throughput requirements for high definition video, addresses the need for a real‐time 3D video playback solution that takes advantage of hardware accelerated graphics, while providing a high degree of flexibility through format configuration and cross‐platform interoperability. A modular component based software solution based on FFmpeg for video demultiplexing and video decoding is proposed,using OpenGL and GLUT for hardware accelerated graphics and POSIX threads for increased CPU utilization. The solution has been verified to have sufficient throughput in order to display 1080p video at the native video frame rate on the experimental system, which is considered as a standard high‐end desktop PC only using commercial hardware. In order to evaluate the performance of the proposed solution a number of throughput evaluation metrics have been introduced measuring average frame rate as a function of: video bit rate, video resolution and number of views. The results obtained have indicated that the GPU constitutes the primary bottleneck in a multi‐view lenticular rendering system and that multi‐view rendering performance is degraded as the number of views is increased. This is a result of the current GPU square matrix texture cache architectures, resulting in texture lookup access times according to random memory access patterns when the number of views is high. The proposed solution has been identified in order to provide low CPU efficiency, i.e. low CPU hardware utilization and it is recommended to increase performance by investigating the gains of scalable multithreading techniques. It is also recommended to investigate the gains of introducing video frame buffering in video memory or to move more calculations to the CPU in order to increase GPU performance.

  • 258.
    Andersson, Håkan
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Mekanik och hållfasthetslära. Linköpings universitet, Tekniska fakulteten.
    A Co-Simulation Approach for Hydraulic Percussion Units2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This Licentiate of Engineering thesis concerns modelling and simulation of hydraulic percussion units. These units are often found in equipment for breaking or drilling in rock and concrete, and are also often driven by oil hydraulics, in which complex fluid-structure couplings are essential for their operation.

    Current methodologies used today when developing hydraulic percussion units are based on decoupled analyses, which are not correctly capturing the important coupled mechanisms. Hence, an efficient method for coupled simulations is of high importance, since these mechanisms are critical for the function of these units. Therefore, a co-simulation approach between a 1D system simulation model representing the fluid system and a structural 3D FE-model is proposed.

    This approach is presented in detail, implemented for two well-known simulation tools and evaluated for a simple but relevant model. The Hopsan simulation tool was used for the fluid system and the FE-simulation software LS-DYNA was used for the structural mechanics simulation. The co-simulation interface was implemented using the Functional Mock-up Interface-standard.

    The approach was further developed to also incorporate multiple components for coupled simulations. This was considered necessary when models for the real application are to be developed. The use of two components for co-simulation was successfully evaluated for two models, one using the simple rigid body representation, and a second where linear elastic representations of the structural material were implemented.

    An experimental validation of the co-simulation approach applied to an existing hydraulic hammer was performed. Experiments on the hydraulic hammer were performed using an in-house test rig, and responses were registered at four different running conditions. The co-simulation model was developed using the same approach as before. The corresponding running conditions were simulated and the responses were successfully validated against the experiments. A parameter study was also performed involving two design parameters with the objective to evaluate the effects of a parameter change.

    This thesis consists of two parts, where Part I gives an introduction to the application, the simulation method and the implementation, while Part II consists of three papers from this project.

  • 259.
    Andersson, Johan
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem.
    Automated Fault Tree Generation from Requirement Structures2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The increasing complexity of today’s vehicles gives drivers help with everything from adaptive cruisecontrol to warning lights for low fuel level. But the increasing functionality also increases the risk offailures in the system. To prevent system failures, different safety analytic methods can be used, e.g.,fault trees and/or FMEA-tables. These methods are generally performed manually, and due to thegrowing system size the time spent on safety analysis is growing with increased risk of human errors. If the safety analysis can be automated, lots of time can be saved.

    This thesis investigates the possibility to generate fault trees from safety requirements as wellas which additional information, if any, that is needed for the generation. Safety requirements are requirements on the systems functionality that has to be fulfilled for the safety of the system to be guaranteed. This means that the safety of the truck, the driver, and the surroundings, depend on thefulfillment of those requirements. The requirements describing the system are structured in a graphusing contract theory. Contract theory defines the dependencies between requirements and connectsthem in a contract structure.

    To be able to automatically generate the fault tree for a system, information about the systems failure propagation is needed. For this a Bayesian network is used. The network is built from the contract structure and stores the propagation information in all the nodes of the network. This will result in a failure propagation network, which the fault tree generation will be generated from. The failure propagation network is used to see which combinations of faults in the system can violate thesafety goal, i.e., causing one or several hazards. The result of this will be the base of the fault tree.

    The automatic generation was tested on two different Scania systems, the fuel level displayand the dual circuit steering. Validation was done by comparing the automatically generated trees withmanually generated trees for the two systems showing that the proposed method works as intended. The case studies show that the automated fault tree generation works if the failure propagationinformation exists and can save a lot of time and also minimize the errors made by manuallygenerating the fault trees. The generated fault trees can also be used to validate written requirementsto by analyzing the fault trees created from them.

  • 260.
    Andersson, Johan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörsvetenskap och fysik.
    Jansson, Ulf
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörsvetenskap och fysik.
    Analys av solcellsanläggningar påverkan på elnätet2015Självständigt arbete på grundnivå (högskoleexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Sammanfattning

    Examensarbetet handlar om vilka effekter mikroproduktion i form av solcellsenheter har och kommer att ha på Karlstads elnät. Via flera mätserier har här sammanställts vad som händer med elkvaliteten i nätet och vilka krav som ställs på elnätsbolag och framtida mikroproducenter. Genom bred teoretisk kunskap och praktiskt arbete med ett antal dataprogram har denna rapport arbetats fram och sammanställts. Vid ett flertal tillfällen har upphovsmännen bakom denna rapport gett sig ut i fält för att på plats ta del utav dagens former av solkraft samt också iakttagit arbetet bakom och inför elkvalitetsundersökningar.Syftet har i grunden varit att ge kunskap inför ökande volymer av mikroproduktion och att förbereda för framtida förändringar och ombyggnationer i det lokala elnätet. Arbetet har resulterat i en tydlig bild av att dagens elnät har goda möjligheter att möta en ökning av producenter med låga produktionsnivåer. Det har konstaterats att försiktighet bör tas vid inkoppling av anläggningar vad gäller enfas och trefas. Eftersträvansvärt är att använda trefasinkoppling för att undvika snedbelastningar i nätet.

  • 261.
    Andersson, Jonas
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Data- och elektroteknik.
    Serialisering av API mellan PC och inbyggda system2010Självständigt arbete på grundnivå (högskoleexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Detta examensarbete behandlar problemet med att testa inbyggda system i kontorsmiljö. För att göra detta och därigenom kunna göra anrop på det inbyggda systemets API, måste detta anrop skickas som ett seriellt datapaket över en seriell kommunikationslänk som TCP/IP.

    Detta möjliggjordes genom att först upprätta en kommunikationslänk med protokollet TCP/IP, där användningen av POSIX-sockets tillämpades. För att packa ner och packa upp funktionsanropen till seriell data implementerades ett protokoll som följdes när detta utfördes. Hantering av data i samband med överföring över TCP/IP sköttes av ett protokoll vid namn BGSFP, ett protokoll som bygger på det tidigare protokollet TSFP.

  • 262.
    Andersson, Magnus
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för fysik och elektroteknik (IFE).
    Elektronikingenjörens vardag: - ett rymdäventyr2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Masteruppsatsen Elektronikingenjörens vardag - ett rymdäventyr är skriven inom programmet yrkeskunnande och professionsutveckling vid Linnéuniversitetet. Uppsatsen beskriver ett yrkeskunnande som både innehåller avancerade datorsimuleringar och handfasta lödningar av elektriska komponenter, där teori och praktik samverkar. Uppsatsen är skriven i essäform, där händelser och situationer i yrkeslivet utforskas.

    Uppsatsen är skriven för att belysa yrkeskunnandet hos en elektronikingenjör från olika synvinklar; arbetslivet, lärandet och moralen. Genom att behandla tre olika sidor av yrket är tanken att få en större insikt om yrkets helhet. 

  • 263.
    Andersson, Magnus
    et al.
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    Espinosa-Arronte, Beatriz
    KTH, Skolan för informations- och kommunikationsteknik (ICT), Mikroelektronik och tillämpad fysik, MAP.
    van der Beek, C. J.
    Nikolaou, M.
    Lidmar, J.
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik.
    Wallin, M.
    A vortex solid-to-liquid transition with fully anisotropic scaling2009Ingår i: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 150, nr 5Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The vortex solid-to-liquid transition has been studied in heavy ion irradiated untwinned single crystals of YBa2Cu3O7-delta with an inclined applied magnetic field. For magnetic fields tilted at angles about 45 degrees away from the columnar defects, we find that the electric resistivity in the vortex liquid regime approaches zero with power laws in the reduced temperature T - T-c that have different exponents in all three spatial directions. Since the symmetry in the problem has been broken in two non-collinear directions by i) the direction of the columnar defects and ii) the direction of the applied magnetic field, our findings give evidence for a new type of critical behavior with fully anisotropic critical exponents. A possible view of the vortex topology for the transition is also suggested.

  • 264.
    Andersson, Marcus
    et al.
    Luleå tekniska universitet.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundmark, Martin
    Larsson, Anders
    Wahlberg, Mats
    Bollen, Math
    Interfering signals and attenuation: potential problems with communication via the power grid2006Ingår i: Proceedings of Nordic Distribution and Asset Management Conference: NORDAC 2006, 2006Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper will give a general overview of the potential problems associated with remote-meter reading via the power grid and describe some of the technologies available. A comparison will be made between the power grid as a communication channel and other, dedicated and shared, channels. Examples will be given of practical cases in which the communication channel does not function in the intended way.

  • 265.
    Andersson, Martin
    Linköpings universitet, Institutionen för systemteknik.
    Konstruktion av förstärkare och insamplingssteg till en PSAADC i 0.25 um CMOS2002Självständigt arbete på grundnivå (yrkesexamen)Studentuppsats
    Abstract [en]

    The aim and goal of this work has been to design and implement a voltage reference network for a 12-bit PSAADC, Parallell Successive Analog to Digital Converter. A chip containing the design has been sent away for fabrication. Because of the long processing time, no measurement data are presented. The main specifications for the voltage reference generator is to generate stable reference voltages with low noise and a good PSRR. Efforts has also been made to minimize the power consumption.

  • 266.
    Andersson, Martin
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Wilson, Anton
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    A microfluidic relative permittivity sensor for feedback control of carbon dioxide expanded liquid flows2019Ingår i: Sensors and Actuators A-Physical, ISSN 0924-4247, E-ISSN 1873-3069, Vol. 285, s. 165-172Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Binary CO2-alcohol mixtures, such as CO2-expanded liquids (CXLs), are promising green solvents for reaching higher performance in flow chemistry and separation processing. However, their compressibility and high working pressure makes handling challenging. These mixtures allow for a tuneable polarity but, to do so, requires precise flow control. Here, a high-pressure tolerant microfluidic system containing a relative permittivity sensor and a mixing chip is used to actively regulate the relative permittivity of these fluids and indirectly—composition. The sensor is a fluid-filled plate capacitor created using embedded 3D-structured thin films and has a linearity of 0.9999, a sensitivity of 4.88 pF per unit of relative permittivity, and a precision within 0.6% for a sampling volume of 0.3 μL. Composition and relative permittivity of CO2-ethanol mixtures were measured at 82 bar and 21 °C during flow. By flow and dielectric models, this relationship was found to be described by the pure components and a quadratic mixing rule with an interaction parameter, kij, of -0.63 ± 0.02. Microflows with a relative permittivity of 1.7–21.4 were generated, and using the models, this was found to correspond to compositions of 6–90 mol % ethanol in CO2. With the sensor, a closed loop control system was realised and CO2-ethanol flows were tuned to setpoints of the relative permittivity in 30 s.

  • 267.
    Andersson, Mathias
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, EISLAB.
    EMC robot1997Rapport (Övrigt vetenskapligt)
  • 268.
    Andersson, Niklas
    et al.
    Ericsson Microelectronics AB.
    Andersson, Ola
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Models and Implementation of a Dynamic Element Matching DAC2003Ingår i: Analog Integrated Circuits and Signal Processing, ISSN 0925-1030, E-ISSN 1573-1979, Vol. 34, nr 1, s. 7-16Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The dynamic element matching (DEM) techniques for digital-to-analog converters (DACs) has been suggested as a promising method to improve matching between the DAC''s reference levels. However, no work has so far taken the dynamic effects that limit the performance for higher frequenciesinto account. In this paper we present a model describing the dynamic properties of a DEM DAC and compare the simulated results with measurements of a 14-bit current-steering DEM DAC implemented in a 0.35-μm CMOS process. The measured data agrees well with the results predicted by the used model. It is also shown that the DEM technique does not necessarily increase the performance of a DAC when dynamic errors are dominating the achievable performance.

  • 269.
    Andersson, Niklas
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem.
    Rudberg, Mikael
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem.
    Improvement of segmented DACs (Swedish pat. 0001917-4)2000Patent (Övrig (populärvetenskap, debatt, mm))
  • 270.
    Andersson, Niklas
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    A strategy for implementing dynamic element matching in current-steering DACs2000Ingår i: Mixed-Signal Design, 2000. SSMSD. 2000 Southwest Symposium on, IEEE , 2000, s. 51-56Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Interesting comparisons of dynamic element matching (DEM) techniques, have been presented during the last decade. However, not many chip implementations of these DEM techniques have been presented so far. A brief review of different DEM techniques are presented in this paper together with a strategy for implementing the partial randomization DEM, PRDEM, technique in a 3.3 V supply, 14 bit CMOS current-steering wideband digital-to-analog converter (DAC)

  • 271.
    Andersson, Niklas
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Comparison of Different Dynamic Element Matching Techniques for Wideband CMOS DACs1999Ingår i: Proceedings of the 17th Norchip Conference, 1999Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In the field of dynamic element matching, DEM, techniques, some ”new” important theoretical results have been presented during the last decade. However, no comparison between these different DEM techniques (FRDEM, PRDEM, NSDEM) used in wideband digital-to-analog converters, DACs, has been reported. A brief review of different DEM techniques and a comparison between their properties in terms of complexity, etc., are presented in this paper together with simulation results showing the impact of using different DEM techniques.

  • 272.
    Andersson, Ola
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Modeling and Implementation of Current-Steering Digital-to-Analog Converters2005Doktorsavhandling, monografi (Övrigt vetenskapligt)
    Abstract [en]

    Data converters, i.e., analog-to-digital converters (ADCs) and digital-to-analog converters (DACs), are interface circuits between the analog and digital domains. They are used in, e.g., digital audio applications, data communication applications, and other types of applications where conversion between analog and digital signal representation is required. This work covers different aspects related to modeling, error correction, and implementation of DACs for communication applications where the requirements on the circuits in terms of speed and linearity are hard. The DAC architecture considered in this work is the current-steering DAC, which is the most commonly used architecture for high-speed applications.

    Transistor-level simulation of complex circuits using accurate transistor models require long simulation times. A transistor-level model of a DAC used in a system simulation is likely to be a severe bottleneck limiting the overall system simulation speed. Moreover, investigations of stochastic parameter variations require multiple simulation runs with different parameter values making transistor-level models unsuitable. Therefore, there is a need for behavioral-level models with reasonably short simulation times. Behavioral-level models can also be used to find the requirements on different building blocks on high abstraction levels, enabling the use of efficient topdown design methodologies. Models of different nonideal properties in current-steering DACs are used and developed in this work.

    Static errors typically dominates the low-frequency behavior of the DAC. One of the limiting factors for the static linearity of a current-steering DAC is mismatch between current sources. A well-known model of this problem is used extensively in this work for evaluation of different ideas and techniques for linearity enhancement. The highfrequency behavior of the DAC is typically dominated by dynamic errors. Models oftwo types of dynamic errors are developed in this work. These are the dynamic errors caused by parasitic capacitance in wires and transistors and glitches caused by asymmetry in the settling behavior of a current source.

    The encoding used for the digital control word in a current steering DAC has a large influence on the circuit performance, e.g., in terms static linearity and glitches. In this work, two DAC architectures are developed. These are denoted the decomposed and partially decomposed architectures and utilize encoding strategies aiming at a high circuit performance by avoiding unnecessary switching of current sources. The developed architectures are compared with the well-known binary-weighted and segmented architectures using behavioral-level simulations.

    It can be hard to meet a DAC design specification using a straightforward implementation. Techniques for compensation of errors that can be applied to improve the DAC linearity are studied. The well-known dynamic element matching (DEM) techniques are used for transforming spurious tones caused by matching errors into white or shaped noise. An overview of these techniques are given in this work and a DEM technique for the decomposed DAC architecture is developed. In DS modulation, feedback of the quantization error is utilized to spectrally shape the quantization noise to reduce its power within the signal band. A technique based on this principle is developed for spectral shaping of DAC nonlinearity errors utilizing a DAC model in a feedback loop. Two examples of utilization of the technique are given.

    Four different current-steering DACs implemented in CMOS technology are developed to enable comparison between behavioral-level simulations and measurements on actual implementations and to provide platforms for evaluation of different techniques for linearity improvement. For example, a 14-bit DEM DAC is implemented and measurement results are compared with simulation results. A good agreement between measured and simulated results is obtained. Moreover, a configurable 12-bit DAC capable of operating with different degrees of segmentation and decomposition is implemented to evaluate the proposed decomposed architecture. Measurement results agree with results from behavioral-level simulations and indicate that the decomposed architecture is a viable alternative to the commonly used segmented architecture.

  • 273.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Andersson, Niklas
    n/a.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    A 14-Bit dual current-steering DAC2003Ingår i: Proc. Swedish System-on-Chip Conf., SSoCC'03, 2003Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A 14-bit dual current-steering digital-to-analog converter implemented in a 0.25 µm CMOS process is presented in this work. Both implementation issues and measurement results are presented. The measured spurious-free dynamic range is higher than 73 dB for signal frequencies up to 3 MHz, and a measured multi-tone power ratio of approximately 71 dB is reported for an ADSL-like input.

  • 274.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Andersson, Niklas
    n/a.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    A differential DAC architecture with variable common-mode level2002Ingår i: Proc. 2002 IEEE Int. Symp. on Circuits and Systems, ISCAS'02, 2002, s. I-113-I-116Konferensbidrag (Refereegranskat)
    Abstract [en]

    A differential current-steering digital-to-analog converter (DAC) architecture allowing the common-mode level of the input signal to be varied is presented. Simulation results with models of different DAC nonlinearities indicate that the proposed architecture has a potential of improving the linearity of the converters.

  • 275.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Andersson, Niklas
    n/a.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    A method of segmenting digital-to-analog converters2003Ingår i: Proc. IEEE Southwest Symposium on Mixed-Signal Design, SSMSD'03, 2003, s. 32-37Konferensbidrag (Refereegranskat)
    Abstract [en]

    Segmented architectures are often used in digital-to-analog converters (DACs). Here we propose a DAC structure based on recursive decomposition of an N-bit binary DAC into two (N-1) bit DACs and one 1 bit DAC. A DAC model that includes matching errors has been simulated. The simulation results indicate that by using four layers of decomposition it is possible to achieve similar performance as when using seven bits of traditional segmentation.

  • 276.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Andersson, Niklas
    n/a.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Combining DACs for improved performance2002Ingår i: Proc. 4th IEE Int. Conf. on Advanced A/D and D/A Conversion Techniques and their Applications, ADDA'02, 2002Konferensbidrag (Refereegranskat)
    Abstract [en]

    This work is an overview of recently proposed methods on combining DACs in order to improve performance. Some further development of these techniques are also presented. The techniques aim at reducing glitches and sensitivity towards limited output impedance in current sources.

  • 277.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Andersson, Niklas
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Spectral shaping of DAC nonlinearity errors through modulation of expected errors2001Ingår i: Circuits and Systems, 2001. ISCAS 2001. The 2001 IEEE International Symposium on, IEEE , 2001, Vol. 3, s. 417-420Konferensbidrag (Refereegranskat)
    Abstract [en]

    Traditionally, delta-sigma modulation has been used for shaping of quantization noise. We present a modified version of delta-sigma modulation which also takes into account unwanted nonlinearities by feeding back not only the quantization error, but also the expected physical error. Behavioral-level simulations of a 5th-order structure showing an improvement of up to 4 effective bits are included

  • 278.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Institutionen för systemteknik, Elektroniksystem.
    A parameterized cell-based design approach for digital-to-analog converters2004Ingår i: Proc. IEEE Int. Workshop on System-on-Chip for Real-Time Applications, IWSOC'04, 2004, s. 225-228Konferensbidrag (Refereegranskat)
    Abstract [en]

    Due to the lack of proper design automation tools, designers are often forced to use full-custom design methodologies when designing analog and mixed-signal circuits. In this work, we discuss a design methodology based on parameterized cells intended for efficient design. The methodology is illustrated with the design of a 12-bit configurable current-steering DAC. Because the cells are parameterized, their layout must be described in a generalized way, resulting in a longer design time compared with a manual layout of a fixed circuit. However, the parameterized approach simplifies iteration of the layout process and block reuse.

  • 279.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik.
    A testbed for different codes in digital-to-analog converters2004Ingår i: Proc. Swedish System-on-Chip Conf. 2004, SSoCC'04, 2004Konferensbidrag (Övrigt vetenskapligt)
  • 280.
    Andersson, Ola
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Elektroniksystem.
    Vesterbacka, Mark
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för systemteknik, Elektroniksystem.
    A yield-enhancement strategy for binary-weighted DACs2005Ingår i: Proc. European Conf. Circuit Theory and Design 2005, ECCTD'05, 2005, , s. 55-58s. 55-58Konferensbidrag (Refereegranskat)
    Abstract [en]

    One of the major contributors to the static nonlinearity of a current-steering digital-to-analog converter (DAC) is mismatch between current sources. A technique for enhancing the yield of binary-weighted current-steering DACs is proposed. The technique utilizes a special case of a general technique for spectral shaping of DAC nonlinearity errors presented earlier and requires oversampling. The technique relies on two DAC models with low computational complexity that can be integrated with the DAC at a negligible cost in terms of area and power consumption. Behavioral-level simulation results indicate that the proposed method has a good potential of enhancing the yield of binary-weighted DACs for situations where the matching errors constitute the dominating source of nonlinearity.

  • 281.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Institutionen för systemteknik, Elektroniksystem.
    Dynamic element matching in decomposed digital-to-analog converters2004Ingår i: Proc. IEEE NORCHIP'04, Denmark: TechnoData A/S , 2004, , s. 187-190s. 187-190Konferensbidrag (Refereegranskat)
    Abstract [en]

    A dynamic element matching (DEM) technique is proposed that aims at improving the spurious-free dynamic range (SFDR) of current-steering digital-to-analog converters (DACs) implemented with a decomposed architecture. The architecture consists of a number of small binary-weighted DACs that are controlled such that only a minimum number of unit current sources are switching for the most critical code transitions. The DEM is obtained by scrambling bit pairs with equal weight. In contrast to most other DEM techniques, the scrambling is performed conditionally so that the number of switching current sources does not increase compared with the unscrambled case. Hence, the good glitch properties of the decomposed converter architecture are maintained. Simulations on a behavioral level of some decomposed DACs have been performed. Assuming random uncorrelated matching errors with Gaussian distribution and a 5% standard deviation, the SFDR value giving 90% yield is increased with 5.6 dB for a 14-bit DAC using scrambling of the two bit pairs with the largest weights. The hardware cost for the required scrambling circuits should be low since only two pairs of bits are scrambled.

  • 282. Andersson, Ola
    et al.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Modeling of glitches due to rise/fall asymmetry in current-steering digital-to-analog converters2005Ingår i: IEEE Transactions on Circuits and Systems I: Regular Papers, ISSN 1549-8328, Vol. 52, nr 11, s. 2265-2275Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The current-steering digital-to-analog converter (DAC) is the most common type of DAC for high-speed applications. Glitches present in the DAC output contribute to nonlinear distortion in the DAC transfer characteristics degrading the circuit performance. One source of glitches is asymmetry in the settling behavior when switching on and off a current source. A behavioral-level model of this nonideal behavior is derived in this work. Further, a method with low computational complexity for estimating the influence of the modeled errors in the frequency domain is developed. This method can be utilized by circuit designers to derive circuit requirements for fulfilling a given frequency-domain specification, potentially relaxing the requirements compared with a worst-case analysis. Examples of model utilization are given in terms of an analytical examination and MATLAB simulations. A good agreement between simulated and analytical results is obtained.

  • 283.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik.
    Vesterbacka, Mark
    Linköpings universitet, Institutionen för systemteknik. Linköpings universitet, Institutionen för systemteknik, Elektroniksystem.
    Partial decomposition of digital-to-analog converters2004Ingår i: Proc. 12th IEEE Mediterranean Electrotechnical Conf., MELECON'04, 2004, s. 193-196Konferensbidrag (Refereegranskat)
    Abstract [en]

    The decomposed DAC architecture was recently proposed as an alternative to the traditional segmented architecture. In this work, we present a modified version of the decomposed architecture with reduced hardware complexity denoted the partially decomposed architecture. Behavioral-level simulations indicate that the partially decomposed architecture is a good alternative for signals with Gaussian distribution, whereas the original decomposed or segmented architectures are preferred for sinusoidal signals.

  • 284.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Characterization of a CMOS current-steering DAC using state-space models2000Ingår i: Circuits and Systems, 2000. Proceedings of the 43rd IEEE Midwest Symposium on, IEEE , 2000, Vol. 2, s. 668-671 vol.2Konferensbidrag (Refereegranskat)
    Abstract [en]

    Performance limitations on current-steering digital-to-analog converters (DACs) are due to finite output impedances, nonideal switches, parasitic capacitances, matching, etc. In this work we present a dynamic state-space model of a 14-bit current-steering DAC which includes dynamic nonidealities. Simulation results are presented and compared to measurement results. The model can be used for fast performance estimation of D/A converters

  • 285.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem.
    Digital-to-analog converter having error correction (US pat. 6946983)2002Patent (Övrig (populärvetenskap, debatt, mm))
  • 286.
    Andersson, Ola
    et al.
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Wikner, Jacob
    Linköpings universitet, Institutionen för systemteknik, Elektroniksystem. Linköpings universitet, Tekniska högskolan.
    Modeling of the Influence of Graded Element Matching Errors in CMOS Current-Steering DACs1999Ingår i: Proceedings of the 17th Norchip Conference, 1999Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In analog and mixed-mode circuits the matching between circuit elements is crucial.For example, in binary encoded digital-to-analog converters (DACs) the matchingbetween different bit weights can set the limit on the performance. Related to earlier workmodeling the influence of stochastic matching, the influence of graded element matching errorson the performance of current-steering DACs is shown. Presented are calculated results thatcorrelate very well with simulated results. As performance measures we use both static measuresas DNL and INL as well as frequency domain parameters as SNDR and SFDR. This discussioncan also be applied to other DAC structures, for example switched-capacitor.

  • 287.
    Andersson, Olof
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Komplexa material och system. Linköpings universitet, Tekniska fakulteten.
    Maas, Joris
    Holst Ctr TNO, Netherlands.
    Gelinck, Gerwin
    Holst Ctr TNO, Netherlands; Eindhoven Univ Technol, Netherlands.
    Kemerink, Martijn
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Scalable Electronic Ratchet with Over 10% Rectification Efficiency2020Ingår i: ADVANCED SCIENCE, ISSN 2198-3844, artikel-id 1902428Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Electronic ratchets use a periodic potential with broken inversion symmetry to rectify undirected (electromagnetic, EM) forces and can in principle be a complement to conventional diode-based designs. Unfortunately, ratchet devices reported to date have low or undetermined power conversion efficiencies, hampering applicability. Combining experiments and numerical modeling, field-effect transistor-based ratchets are investigated in which the driving signal is coupled into the accumulation layer via interdigitated finger electrodes that are capacitively coupled to the field effect transistor channel region. The output current-voltage curves of these ratchets can have a fill factor amp;gt;amp;gt; 0.25 which is highly favorable for the power output. Experimentally, a maximum power conversion efficiency well over 10% at 5 MHz, which is the highest reported value for an electronic ratchet, is determined. Device simulations indicate this number can be increased further by increasing the device asymmetry. A scaling analysis shows that the frequency range of optimal performance can be scaled to the THz regime, and possibly beyond, while adhering to technologically realistic parameters. Concomitantly, the power output density increases from approximate to 4 W m(-2) to approximate to 1 MW m(-2). Hence, this type of ratchet device can rectify high-frequency EM fields at reasonable efficiencies, potentially paving the way for actual use as energy harvester.

  • 288.
    Andersson, Oscar
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Energikombinat i Halmstads fjärrvärmesystem2007Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats
    Abstract [sv]

    Klimatförändringar börjar allt mer få en viktig roll i allas vardag och för energibranschen har arbetet med att minska miljöpåverkan bara börjat. Branschen har sedan en tid tillbaka premierat fjärrvärme som bra miljöval för uppvärmningskälla för bostäder och lokaler. Faktum kvarstår dock att beroende på hur fjärrvärmesystemet ser ut så påverkar näten miljön olika. I denna rapport behandlas det lokala energibolaget Halmstads Energi och Miljös fjärrvärmesystem genom en optimering av systemkostnaden. Utifrån optimeringen studeras sedan skuggpriser, drift och miljöpåverkan för systemet. Studien behandlar även de stora fördelarna med att energibolaget samarbetar med en eventuellt kommande energikrävande industrier, i detta fall en etanolfabrik. I och med samarbetet bildas ett energikombinat där fjärrvärme, el och etanol tillverkas.

    För analysen används ett energisystemperspektiv som får större geografiska gränser än bara Halmstad. Undersökningen av systemet görs med hjälp av datorprogrammet MODEST som är ett energioptimeringsprogram som utvecklats på Linköpings Tekniska högskola. Modellen av Halmstads fjärrvärmenät baseras och valideras mot driftsäsongen 2005 och har visat sig stämma med verkligheten bra.

    Resultatet visar att Halmstad Energi och Miljö planerade effekthöjningar används fullt ut men att det nätet kommer få stora effekttoppar inom en snar framtid. Energikombinatet som analyseras visar sig både ha ekonomiska som miljöfördelar för både energibolaget och en etanolfabrik. Spillvärmen som kan utvinnas kan även den minska användningen av topplastanläggningarna i fjärrvärmenätet.

  • 289. Andersson, Oskar
    Savonius wind turbine innovation integrated in a constructed nano grid system2019Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    A nanogrid system for supplying neutrino detectors on Antarctica with electricity is

    designed and built. The nanogrid system could later on be implemented in various

    configurations where suppling electricity to neutrino detectors is one area of use.

    The energy system that is acting on site in Antarctica is based around solar panels

    to provide power to the measuring equipment. However, providing electricity in

    such a way is not optimal due to its failure in delivering electricity at times. A

    nanogrid that can stand the demands of constant energy supply to the

    measurement station are therefore constructed. The energy sources that are

    integrated into the nanogrid are an innovation in vertical axis wind turbine and

    photovoltaics. The wind turbine innovation is tested under real conditions for the

    first time. In the constructed nanogrid, there are also integrated energy storage

    consisting of battery cells that are coupled together to a coherent unit.

    Measurement equipment is also implemented for analyzation of acting wind turbine

    as well as different types of safety equipment for redundancy in the system. In the

    nanogrid, a rectifier for AC to DC transformation is constructed. An inverter for DC

    to AC transformation is also implemented for supplying electricity to the

    equipment that are acting on the grid.

    The system is tested under real conditions. The whole system could observe

    partially function and configurated well to the various parts of the whole system.

    Further optimisation of some parts of the system from the prototype is needed.

  • 290.
    Andersson, Per-Oskar
    Linköpings universitet, Institutionen för systemteknik.
    Rhapsody on small processor platforms2008Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats
    Abstract [sv]

    Rhapsody är ett verktyg för modelldriven utveckling och design av inbyggda system och realtidssystem. Syftet med detta examensarbete är att undersöka om Rhapsody kan användas för att utveckla mjukvara till små processorplattformar som Atmel’s AVR. Då Rhapsody normalt används till plattformar med ett operativsystem behöver vissa modifieringar göras för att möjliggöra utveckling mot plattformar utan operativsystem. Dessa modifieringar, deras för och nackdelar samt påverkan på utvecklingsprocessen undersöks medan AVR-mjukvara porteras till Rhapsody. Mjukvaran som porteras är en del av styrsystemet till en av CC Systems produkter: CC Pilot XL II, en robust fordonsdator.

  • 291.
    Andersson, Peter
    Linköpings universitet, Institutionen för systemteknik.
    Design of a channel board used in an electronic warfare target simulator2006Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats
    Abstract [en]

    A channel board was designed for a DRFM circuit. The DRFM is implemented in a Virtex-4 FPGA from Xilinx. In the future a similar channel board is intended to be used for target echo generation in ELSI which is an electronic warfare simulator at Saab Bofors Dynamics in Linköping.

    Besides the DRFM circuit the channel board consists of analog-to-digital converters, digital-to-analog converters, Ethernet plug-in board with a microcontroller, voltage regulators, FPGA configuration memory, voltage amplifiers, current amplifiers, oscillator, buffers/drivers and bus transceivers. The sample rate is 200 MHz and LVDS signalling standard is used between the DRFM circuit and the converters.

    The channel board has a JTAG interface which enables in-system programming of the FPGA. This implies that the DRFM can easily be redesigned. An external computer can manage the channel board via Ethernet. Software was developed for the microcontroller on the channel board and for the external computer. The function of the channel board is heavily dependent on the DRFM circuit.

    The channel board design resulted in the assembly of a prototype circuit board. Measurements were performed in a lab and the channel board was approved to be integrated in ELSI for further tests.

  • 292.
    Andersson, Peter
    Linköpings universitet, Institutionen för systemteknik.
    Implementering av digitalt vågfilter av Richardstyp i FPGA2002Självständigt arbete på grundnivå (yrkesexamen)Studentuppsats
    Abstract [sv]

    Ett digitalt vågfilter av Richardstyp har implementerats i en FPGA på ett utvecklingskort. Sampel kan skickas till filtret och mottas från filtret via serieporten på en dator. Metoden som användes är att en modell av filtret konstruerades i Simulink. Filtret har modifierats med avseende på skalning, brus och stabilitet. VHDL-koden till filtret genererades i Simulink genom att bygga modellen av Xilinx Blockset. Ytterligare VHDL-kod konstruerades för att kunna skicka sampel mellan filter och minnet på utvecklingskortet. För kommunikation mellan minnet på utvecklingskortet och dator utnyttjades färdiga lösningar.

  • 293.
    Andersson, Peter
    Linköpings universitet, Institutionen för systemteknik.
    Överföring av digital video via FireWire2002Självständigt arbete på grundnivå (yrkesexamen)Studentuppsats
    Abstract [en]

    Transmission of digital signals is today more frequently used than transmission of analog signals. One reason for this is that a digital signal is less sensitive to noise than an analog, another reason is that almost all signals today are handled in a digital format. This thesis describes the development of a system that receives digital video signals through FireWire. The standard for FireWire, which is a high performance serial bus, is under development. Today the standard of the bus supports transmission of data with a speed of up to 400 Mbit/s. In the future FireWire is supposed to transmit data with a speed of up to 3,2 Gbit/s. The thesis gives an introduction to the technique for FireWire and how it is implemented. It also includes a short description of digital video signals in DVCAM format.

  • 294.
    Andersson, Pontus
    Linköpings universitet, Institutionen för teknik och naturvetenskap.
    Visuell processreglering2007Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats
    Abstract [sv]

    Examensarbetet handlar om att ta fram en processmodell för nivåreglering och det innehåller flera utmaningar. Vätskesystemets dynamik och balans måste beaktas likväl som lämpliga reglermetoder samt modellens utseende. I den här rapporten behandlas hela händelseförloppet från initialskedet till en färdig produkt redo att visas för en publik. Läsaren får möjlighet att närmare granska de komponenter som modellen är uppbyggd av, ta del av programmeringsarbetet och de omfattande test av modellen som utförts. Flera teknikområden belyses men fokus riktas särskilt på ABB:s styrsystem AC800M/800xA, fältbussteknik och reglerstrategier. PID-regulatorn har under arbetet spelat en stor roll och reglerstrategier som innefattar bl.a. framkoppling och kaskadkoppling analyseras och diskuteras. För att bedöma skillnader i val av reglermetod används grafer från praktiska försök. Rapportens upplägg med flertalet illustrationer och den genomgripande tekniska dokumentationen hjälper läsaren att förstå modellens funktion och uppbyggnad.

  • 295.
    Andersson, Robby
    Linköpings universitet, Institutionen för systemteknik.
    FPGA design of a controller for a CAN controller.2003Självständigt arbete på grundnivå (yrkesexamen)Studentuppsats
    Abstract [en]

    This diploma work describes how an FPGA is designed to control a CAN controller. It describes the different tools used when working with Actel’s design tools and the sequence of work applied. It gives a short overview of a multiplexer, the CAN bus, an analog/digital-converter and some more information on the actual FPGA. It also brings up the design process of the FPGA, planning, coding, simulating, testing and finally programming the FPGA. The different parts implemented in the FPGA are a shift-register and two state- machines that are connected with each other. They work together to control the SJA1000 CAN controller made by Philips. They also receive data from the analog/digital-converter that they forward onwards to the CAN controller that forward the data on the CAN bus.

  • 296.
    Andersson, Robin
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Electric power quality in low voltage grid: Office buildings and rural substation2015Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The modern society uses more and more electronic devices needed to being able to function together. This put higher demands on the electrical grid together with that the typical load have changed from the past. Therefore utility companies are obliged to keep the voltage within certain limits for this to function. What exact these limits have been have not always been clear since they have not been gathered in one single document. 

    This thesis is a cooperation with Kraftringen who also has been the initiator. Kraftringen would like to become more proactive in their work regarding electric power quality. For becoming more proactive continuously measurements have to be done but the locations have to be carefully selected in the beginning to get a wider perspective of the grid.

    Energy markets inspectorate (EI) is supervisory of the electric power quality in Sweden and since 2011 they have published a code of statutes (EIFS 2011:2 later 2013:1) intended to summarize limits on voltage. Some of the electrical power quality aspects are not mentioned in EIFS 2013:1 and standards have to be used to find limited values. Flicker and interharmonics are not mentioned in EIFS 2013:1 and for values on flicker the standard SS-EN 50160 has to be used and for interharmonics the standard SS-EN 61000-2-2 state limit values. Besides all this there are standards with stricter limits than EIFS 2013:1 e.g. for total harmonic distortion on voltage were SS-EN 61000-2-2 suggest 6 % instead of 8 %.

    Three different field studies have been conducted in order to get some perception of the present situation regarding electric power quality. Two measurements were conducted on a typical office building because they represents a large part of the typical load in Lund. The third measurement was conducted on a substation in a rural area to get a perception of the situation outside urban areas. 

    These measurements shown that the overall electric power quality was within given limits according to EIFS 2013:1 and different standards. However, conducted measurements shown some interesting results. Both the typical office buildings have a slightly capacitive power factor which results in that the voltage inside the building is going to be slightly higher than at the substation. Since the voltage level at the measured urban substation was above nominal voltage level with about 2-5 % this could be problematic. Another eventual problem with a load with a capacitive power factor is resonance with the inductive parts of the grid like transformers leading to magnified harmonic levels.

    It is suggested that Kraftringen expand their number of permanent electric power quality measurement locations to get a better overview of the present situation. The best suited locations to start with are such that have received complaints earlier, preferably measured on the low voltage side of the transformer for also register the amount of zero sequence harmonics. Next step in the measurement expansion would be substations known to be under higher load than others or substations with a PEN-conductor in a smaller area than the phase conductors, supplying a typical office load with high amounts of third harmonics and unbalance. From this it would be appropriate to spread out the measurement locations geographically to better get to know the grids behaviour. 

  • 297.
    Andersson, Sam
    Linnéuniversitetet, Fakulteten för teknik (FTK), Sjöfartshögskolan (SJÖ).
    Induktionsladdning av hybriddrivna fartyg: En framtida lösning för kustfartyg2018Självständigt arbete på grundnivå (högskoleexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Projektet syftar till att bredda kunskapen om induktionsladdning och belysa de för- och nackdelar tekniken bär med sig på utrustning och kringliggande system.

    Med nya strikta krav på sänkta CO2 utsläpp väljer många redare att konvertera dieseldrivna färjor till hybrid eller helbatteridrift. För att tidseffektivisera hamnuppehållen krävs nya innovativa metoder för energiöverföring. Induktionsladdning av fartyg har provats på det norska fartyget MS Folgefonn med lyckat resultat.

    Utmaningarna med att upprätta en fungerande laddstation med sändenhet och mottagarenhet på ett fartyg, som på grund av väderförhållanden inte hålls helt stagnerad, har varit komplicerade.

    Belastningen på det lokala elnätet har också försvårat processen med en energiöverföring i den magnituden, på så mycket som 1 MW effekt.

  • 298.
    Andersson, Sebastian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Centralised Distribution Grid Energy Storage Systems: Placement and Utilisation for Grid Expansion Deferment2018Självständigt arbete på avancerad nivå (yrkesexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Following an ongoing change towards an increasingly renewable power generation system Swedish grid operators are facing several challenges in coming years. As authorities plan for the decommissioning of nuclear power an increased reliance on de-centralised energy sources such as photo-voltaic distributed generation (PVDG) is expected. A technology observed in some cases to accompany local power quality issues severe enough to impose grid expansion measures from distribution system operators (DSOs). Considering a combination of an indicative utilisation inefficiency of classical grid expansion measures and a recent year maturing of various energy storage technologies, this report sets out to evaluate the possibility of utilising centralised energy storage systems (ESSs) for deferment of classical grid expansion measures.

    For the purpose of identifying the most prominent problem scenarios of modern production- and consumption behaviours as well as the possible solutions offered by centralised ESSs, a literature review of journal articles and technical reports was conducted in combination with a case-study of an existing urban grid operated by Umeå Energi Elnät AB (UEEN). The work regarding ESSs is directed with specific focus towards evaluating which ESS services can potentially facilitate grid expansion deferment and what ESS placement is advisable for efficient utilisation. Assessing possible grid safety implications, potential for peak load shaving and the presently most suitable energy storage technology was also within the scope of the study.

    The literature review reveals PVDG induced feeder line over-voltage and transformer overload the most likely and previously observed implications imposing grid expansion measures. The former more prominent in elongated, typically rural, grids and the latter in more densely populated urban grids. For deferment of over-voltage related grid expansion measures a centralised ESS can be utilised for voltage support provided placement is made close to the affected grid section, presumably far out the affected feeder line. This result is coherent throughout the reviewed literature and is supported by the results of the case-study. Distribution transformer overload and its imposed grid expansion measures can be deferred through load re-allocation and peak load shaving, two services proven achievable by centralised ESSs and the capacity for which increases if ESS placement is made closer the distribution transformer.

    Provided present regulatory and standards are adhered to upon installation, significant negative impact of centralised ESSs on distribution grid safety can be avoided. Most energy storage technologies, including battery based energy storage technologies indicated from the literature review providing the most suitable characteristics for use in centralised distribution grid ESSs, utilise well established systems for grid connection hence no presently unsolvable grid safety implications are identified. Technical reports of real applications of centralised ESSs reinforce this argument as successful implementation without ESS caused grid safety implications have been achieved in the Swedish distribution grid in the past.

  • 299.
    Andersson, Stefan
    Linköpings universitet, Institutionen för systemteknik, Elektroniska komponenter. Linköpings universitet, Tekniska högskolan.
    Multiband LNA Design and RF-Sampling Front-Ends for Flexible Wireless Receivers2006Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The wireless market is developing very fast today with a steadily increasing number of users all around the world. An increasing number of users and the constant need for higher and higher data rates have led to an increasing number of emerging wireless communication standards. As a result there is a huge demand for flexible and low-cost radio architectures for portable applications. Moving towards multistandard radio, a high level of integration becomes a necessity and can only be accomplished by new improved radio architectures and full utilization of technology scaling. Modern nanometer CMOS technologies have the required performance for making high-performance RF circuits together with advanced digital signal processing. This is necessary for the development of low-cost highly integrated multistandard radios. The ultimate solution for the future is a software-defined radio, where a single hardware is used that can be reconfigured by software to handle any standard. Direct analog-to-digital conversion could be used for that purpose, but is not yet feasible due to the extremely tough requirements that put on the analog-to-digital converter (ADC). Meanwhile, the goal is to create radios that are as flexible as possible with today’s technology. The key to success is to have an RF front-end architecture that is flexible enough without putting too tough requirements on the ADC.

    One of the key components in such a radio front-end is a multiband multistandard low-noise amplifier (LNA). The LNA must be capable of handling several carrier frequencies within a large bandwidth. Therefore it is not possible to optimize the circuit performance for just one frequency band as can be done for a single application LNA. Two different circuit topologies that are suitable for multiband multistandard LNAs have been investigated, implemented, and measured. Those two LNA topologies are: (i) wideband LNAs that cover all the frequency bands of interest (ii) tunable narrowband LNAs that are tunable over a wide range of frequency bands.

    Before analog-to-digital conversion the RF signal has to be downconverted to a frequency manageable by the analog-to-digital converter. Recently the concept of direct sampling of the RF signal and discrete-time signal processing before analog-to-digital conversion has drawn a lot of attention. Today’s CMOS technologies demonstrate very high speeds, making the RF-sampling technique appealing in a context of multistandard operation at GHz frequencies. In this thesis the concept of RF sampling and decimation is used to implement a flexible RF front-end, where the RF signal is sampled and downconverted to baseband frequency. A discrete-time switched-capacitor filter is used for filtering and decimation in order to decrease the sample rate from a value close to the carrier frequency to a value suitable for analog-to-digital conversion. To demonstrate the feasibility of this approach an RF-sampling front-end primarily intended for WLAN has been implemented in a 0.13 μm CMOS process.

  • 300.
    Andersson, Stefan
    et al.
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap.
    Johansson, Andreas
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap.
    Tillämpning av effektstabilisering i PLC2008Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats
    Abstract [sv]

    Syftet med examensarbetet är att digitalt tillämpa en stabilisering av pendlingar i den aktiva effekten hos en synkrongenerator för vattenkraft kopplad till ett distributionsnät.

    Implementeringen är tänkt att ske i en PLC som redan hanterar andra delar av magnetiseringen.

    Effektstabiliseringen görs genom att en motverkande styrsignal skickas till magnetiseringsutrustningen vilken i sin tur påverkar generatorns uteffekt. Denna motverkande styrsignal kan tas fram på olika sätt.

    Två modeller, av IEEE standardiserade, för effektstabilisering undersöks, PSS1A och PSS2B.

    En Simulink-modell över ett distributionsnät med generator byggs upp för att testa effektstabiliseringen.

    Diskretisering av den ena standarden utförs för att digital implementering ska kunna ske. Tester utförs även på denna modell för att kunna validera dess funktion i jämförelse med den kontinuerliga.

    Den tidsdiskreta modellen görs om till ett matematiskt uttryck tillämpbart i PLC:n.

    Jämförelse sker mellan simuleringarna och den tillämpade modellen genom mätningar.

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