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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
261

Exploring Sustainable Industrial Software System Development : within the Software Architecture Environment

Stoll, Pia January 2009 (has links)
This thesis describes how sustainable development definitions can be transposed to the software architecture environment for the industrial software system domain. In a case study, sustainable development concerns from three companies are investigated for their influence on the dimensions of sustainable development: economical, environmental, and social sustainability. Classifying the case study’s concerns, in the thesis’s Software Engineering taxonomy, shows that the software development concerns are in majority and the software architecture concerns surprisingly few. The economical sustainability concerns dominate followed by social sustainability concerns, including both concerns successfully met and concerns to be met. Sustainable industrial software system development is in the thesis defined as: “Sustainable industrial software system development meets current stakeholders’ needs without compromising the software development organization’s ability to meet the needs of future stakeholders”. Understanding current and future stakeholders concerns is necessary for the formulation of sustainability goals and metrics. Clarifying the interrelationships among stakeholders’ concerns’ impact on business goals and software qualities, in the thesis’s Influencing Factors method, proves to help stakeholders understand their future needs. Trust is found to be critical for sustainable development. For the establishing of trust between system and system users, the usability quality is vital. To implement usability support in the architecture in the early design phase, reusable architectural responsibilities are created. The reusable architectural responsibilities are integrated into an experience factory and used by the product line system architects, resulting in a return of investment of 25:2. / Pasas- Analyzing the enterprise-, system-, and software architecture impact of stakeholders’ concerns for profitable industrial software systems
262

Power Amplifier Circuits in CMOS Technologies

Fritzin, Jonas January 2009 (has links)
The wireless market has experienced a remarkable development and growth since the introduction of the first mobile phone systems, with a steady increase in the number of subscribers, new application areas, and higher data rates. As mobile phones and wireless connectivity have become consumer mass markets, a prime goal of the IC manufacturers is to provide low-cost solutions. The power amplifier (PA) is a key building block in all RF transmitters. To lower the costs and allow full integration of a complete radio System-on-Chip (SoC), it is desirable to integrate the entire transceiver and the PA in a single CMOS chip. While digital circuits benefit from the technology scaling, it is becoming significantly harder to meet the stringent requirements on linearity, output power, and power efficiency of PAs at lower supply voltages. This has recently triggered extensive studies to investigate the impact of different circuit techniques, design methodologies, and design trade-offs on functionality of PAs in nanometer CMOS technologies. This thesis addresses the potential of integrating linear and highly efficient PAs and PA architectures in nanometer CMOS technologies at GHz frequencies. In total four PAs have been designed, two linear PAs and two switched PAs. Two PAs have been designed in a 65nm CMOS technology, targeting the 802.11n WLAN standard operating in the 2.4-2.5GHz frequency band with stringent requirements on linearity. The first linear PA is a two-stage amplifier with LC-based input and interstage matching networks, and the second linear PA is a two-stage PA with transformer-based input and interstage matching networks. Both designs were evaluated for a 72.2Mbit/s, 64-QAM 802.11n OFDM signal with a PAPR of 9.1dB. Both PAs fulfilled the toughest EVM requirement of the standard at average output power levels of 9.4dBm and 11.6dBm, respectively. Matching techniques in both PAs are discussed as well. Two Class-E PAs have been designed in 130nm CMOS and operated at low ‘digital’ supply voltages. The first PA is intended for DECT, while the second is intended for Bluetooth. At 1.5V supply voltage and 1.85GHz, the DECT PA delivered +26.4dBm of output power with a drain efficiency (DE) and poweradded efficiency (PAE) of 41% and 30%, respectively. The Bluetooth PA had an output power of +22.7dBm at 1.0V with a DE and PAE of 48% and 36%, respectively, at 2.45GHz. The Class-E amplifier stage is also suitable for employment in different linearization techniques like Polar Modulation and Outphasing, where a highly efficient Class-E PA is crucial for a successful implementation.
263

Practice-based Improvements in Healthcare

Andersson, Ann-Christine January 2010 (has links)
A central problem for the healthcare sector today is how to manage change and improvements. In recent decades the county councils in Sweden have started various improvement initiatives and programs in order to improve their healthcare services. The improvement program of the Kalmar county council, which constitutes the empirical context for this thesis, is one of those initiatives. The purpose of this thesis is to contribute to a broader understanding of large-scale improvement program in a healthcare setting. This is done by analyzing practitioner’s improvement ideas, describing participants in the improvement projects, revising and testing a survey to measure the development of improvement ideas and describing the improvement program from a theoretical perspective. The theoretical change model used looks at change from two opposing directions in six dimensions; Goals, Leadership, Focus, Process, Reward system and Use of consultants. The aims of the county council improvement program are to become a learning organization, disseminate improvement methodologies and implement continuous quality improvements in the organization. All healthcare administrations and departments in the county council were invited to apply for funds to accomplish improvement projects. Another initiative invited staff teams to work with improvement ideas in a program with support from facilitators, using the breakthrough methodology. Now almost all ongoing developments, improvements, patient safety projects, manager and leader development initiatives are put together under the county council improvement program umbrella. In the appended papers both qualitative and quantitative research approach were used. The first study (paper I) analyzed which types of improvement projects practitioners are engaged in using qualitative content analysis. Five main categories were identified: Organizational Process; Evidence and Quality; Competence Development; Process Technology; and Proactive Patient Work. Most common was a focus on organizational changes and process, while least frequent was proactive patient work. Besides these areas of focus, almost all aimed to increase patient safety and increase effectiveness and availability. Paper II described the participants in two of the initiatives, the categorized improvement projects in paper I and the team members in the methodology guided improvement programs. Strong professions like physicians and nurses were well represented, but other staff groups were not as active. Managers were responsible for a majority of the projects. The gender perspective reflected the overall mix of employees in the county council. Paper III described a revision and test of a Minnesota Innovation Survey (MIS) that will be used to follow and measure how quality improvement ideas develop and improve over time. Descriptive statistics were presented. The respondents were satisfied with their work and what they had accomplished. The most common comment was about time, not having enough time to work with the improvement idea and the difficulty of finding time because of regular tasks. This was the first test of the revised survey and the high use of the answer alternative “Do not know” showed that the survey did not fit the context very well in its present version. Trying to connect the county council improvement program and the initiatives studied in papers I and II with the change model gave rise to some considerations. The county council improvement program has an effort to combine organizational changes and a culture that encourages continuous improvements. Top-down and bottom-up management approaches are used, through setting out strategies from above and at the same time encouraging practitioners to improve their day-to-day work. Whether this will be a successful way to implement and achieve a continuous improvement culture in the whole organization is one of the main issues remaining to find out in further studies.
264

Performance and performance measurements in complex product development

Johnsson, Stefan January 2008 (has links)
In today’s competitive environment, in which competition increases and the pace of technological change accelerates, the need for deploying product development investments more efficiently and effectively is stronger than ever. The ability to create streams of new successful products to the market is vital for every product delivering company’s survival. Performance measurements are important in order to evaluate the current state of operation of the product development and decide on actions to improve its’ performance. However, in contrast to the concept of productivity in the production process there are no commonly adopted methods for measuring performance within product development. The methodology used in this research is explorative multiple case studies at five companies developing complex products. Complex products in this research involve mechanics, electronics, and software. Moreover, complex products are often long living and most development work is evolutionary in character. An extensive interview study among senior managers and decision makers has been conducted to get a broad and systematic understanding of what performance is and what to measure. The main results developed from this research are two conceptual tools. The first one, the Performance Measurement Evaluation Matrix (PMEX) can be used to evaluate the performance measurement system used at a company. The PMEX makes it possible for managers to get a more holistic view and discuss what the performance measurement system is measuring, and what it is not measuring, in order to decide on what to measure. The second tool, the Product Development Organizational Performance Model (PDOPM) can be used to conceptually analyze performance in the product development process from a holistic system perspective. This is achieved by making efficiency, effectiveness, and uncertainty explicit and by showing how they relate at a strategic, project, and product implementation level. The PMEX and the PDOPM can be used by managers in order to increase the understanding of what performance is and to be able to decide on actions in order to improve the performance of the product development process.
265

Studying Buoy Motion for Wave Power : Experiments at the Lysekil Research Site

Tyrberg, Simon January 2009 (has links)
Since 2002, the Division for Electricity at Uppsala University has been running the Lysekil project. The project is an attempt to construct and evaluate a technology for extracting electrical energy from the motion of ocean waves. The idea is to let this up-and-down motion drive a linear generator. A buoy moves thus in the waves, and is connected through a line to the generator at the sea floor. Three such wave energy converters, L1, L2, and L3, and a marine substation have been deployed in the ocean southwest of Lysekil on the Swedish west coast, at the Lysekil research site. Measuring equipment has also been deployed, together with a number of buoys for studying environmental impact. A measuring station has been installed on the nearby island of Hermanö, and an observation tower has been built on the islet of Klammerskär, south of the research site. This licentiate thesis describes the author's work on studying wave buoy motion and is based on five scientific papers, covering mainly two areas. Firstly, changes in water levels, and thereby changes in the equilibrium point for the buoy and generator, have been related to the ability of L1 to absorb energy. The results indicate that there is a correlation between water levels and energy absorption for L1 for the studied time period. When the water level deviates from average, the absorption values decrease. This is not unexpected, since the linear generator has a finite stroke. The effect is however noticeable primarily for water level deviations of more than 25 cm, and is only visible for those cases where either wave height or water level deviation is large. Secondly, the above mentioned observation tower has been designed and built. The tower is equipped with a network camera covering the research site, a wireless communication system and an energy system. The first acquired images of the buoy connected to L1, taken during the summer of 2008, have been analyzed, and buoy motion data has been extracted. The observation system has worked well, and the data on buoy motion (vertical motion in the range of +/-0.5 m correlates fairly well to measurements of significant wave height for the period (Hm0=0.82 m). A comparison with voltage data from the generator also indicates that the system has captured the dominating buoy motion. However, the system suffers from poor temporal resolution (about one image per second), and has not yet been synchronized with the other measurement systems at the site. Addressing these two problems is of high priority in the future.
266

Efficient heat supply and use from an energy-system and climate perspective

Danestig, Maria January 2009 (has links)
The aim of this thesis is to illustrate whether the heat demand in district heating systems can be seen as a resource that enables efficient energy utilization, how this can be achieved and to discuss consequences of this assumption. Based on the answers to posed research questions and on the studies included in this thesis, it is concluded that the hypothesis “A common system approach for energy supply and heat demand will show climate and economic efficient solutions” is true. In cold-climate countries, energy for heating of buildings is essential and heating options that interplay with the power system through electricity use or generation have potential for efficiency improvements. In Sweden, district heating is used extensively, especially in large buildings but to a growing extent also for small houses. Some industrial heat loads and absorption cooling can complement space heating demand so that the production resources may be more evenly utilised during the seasons of the year. Rising electricity prices in recent years cause problems for the extensive use of electric heating in Sweden and further switching to district heating should be a possible option. To be economically favourable, district-heating systems require a certain heat load density. New low-energy houses and energy-efficiency measures in existing buildings decrease the heat demand in buildings and, thus, in district heating systems. Optimisation models have been used in several studies of large, complex energy systems. Such models allow scenarios with changing policy instruments and changed consumer behaviour to be analysed. Energy efficiency measures as well as good conditions for efficient electricity generation, which can replace old, inefficient plants, are needed to reduce carbon dioxide emissions from the energy sector. Results when having a European energy perspective to studies of changes in Sweden differ from when having for example a Swedish energy system perspective The effects on global carbon dioxide emissions, when studying combined heat and power electricity generation in Sweden, are greater than it is on local emissions. / Eftersom höjda elpriser under senare år orsakar problem för den stora användningen av elvärme, kommer ytterligare konvertering till fjärrvärme att vara ett möjligt alternativ. För att vara ekonomiskt fördelaktigt kräver fjärrvärme en viss värmetäthet. Nya lågenergihus och energieffektiviseringsåtgärder i befintliga byggnader minskar värmebehovet i byggnaderna och då även i fjärrvärmesystemen.Syftet med denna avhandling är att visa om värmebehovet i fjärrvärmesystem kan betraktas som en resurs som möjliggör ett effektivt energiutnyttjande, hur detta i så fall kan uppnås och att diskutera följderna av att göra ett sådant antagande. Baserat på svaren på ställda forskningsfrågor och studier som genomförts har hypotesen som lyder; En gemensam systemsyn för både tillförsel och användning av energi för uppvärmningsändamål leder till ekonomiskt såväl som ur klimatsynpunkt effektiva lösningar, visat sig stämma. I länder med kallt klimat är energi för uppvärmning av byggnader viktigt och uppvärmningsalternativ som samverkar med elsystemet genom elanvändning eller elproduktion har potential för effektivitetsförbättringar. I Sverige är fjärrvärmeanvändningen utbredd, speciellt i större byggnader men användningen ökar också i småhus. Vissa industriella värmelaster och absorptionskyla kan fungera som komplement till andra värmebehov i fjärrvärmesystem så att produktionsresurser kan användas mer jämnt fördelat över året. Optimeringsmodeller har använts i flera studier för stora, komplexa energisystem. I dessa kan scenarier med olika styrmedel och förändrad energianvändning analyseras. Nya användningsområden för spillvärme, som att använda värme till absorptionskyla och att växla från olja och el till fjärrvärme i industriella processer kan också studeras. Energieffektiviseringsåtgärder såväl som bra förutsättningar för effektiv elproduktion, som kan ersätta gamla ineffektiva anläggningar behövs för att minska koldioxidutsläppen från energisektorn. Resultaten då ett europeiskt energisystemperspektiv använts, för att studera förändringar i Sverige, skiljer sig från när endast ett svenskt systemperspektiv använts. Påverkan på globala koldioxidutsläpp, då elproduktion från kraftvärme i Sverige studeras, är större än vad påverkan på lokala utsläpp är.
267

Multi-robot Information Fusion : Considering spatial uncertainty models

Andersson, Lars January 2008 (has links)
The work presented in this thesis covers the topic of deployment for mobile robot teams. By connecting robots in teams they can perform a better job than each individual is capable of. It also gives redundancy, increases robustness, provides scalability, and increases efficiency. Multi-robot Information Fusion also results in a broader perspective for decision making. This thesis focuses on methods for estimating formation and trajectories and how these can be used for deployment of a robot team. The problems covered discuss what impact trajectories and formation have on the total uncertainty when exploring unknown areas. The deployment problem is approached using a centralized Kalman filter, for investigation of how team formation affects error propagation. Trajectory estimation is done using a smoother, where all information is used not only to estimate the trajectory of each robot, but also to align trajectories from different robots. Both simulation and experimental results are presented in the appended papers. It is shown that sensor placements can substantially affect uncertainty during deployment. When deploying a robot team the formation can be used as a tool for balancing error propagation among the robot states. A robust algorithm for associating rendezvous observations to align robot trajectories is also presented. Trajectory alignment is used as an efficient and cost-effective method for joining mapping information within robot teams. When working with robot teams, sensor placement and formation should be considered to obtain the maximum from the system. It is also of great value to mix robots with different characteristics since it is shown that using sensor fusion the robots can inherit each other’s characteristics if sensors are used correctly. Information sharing requires modularity and general models, which consumecomputational resources. Over time computer resources will become cheaper, allowing for distribution, and each robot will become more self-contained. Together with increased wireless bandwidth this will enable larger numbers of robots to cooperate.
268

The use of structural equation modeling to describe the effect of operator functional state on air-to-air engagement outcomes

Castor, Martin January 2009 (has links)
Computational evidence of the operative usefulness of a new system is crucial in large system development processes concerning billions of euros or dollars. Although it is obvious that the human often is the most important and critical component of many systems, it has often been hard for Human Factors researchers to express human aspects in a computational and strict way. The thesis describes, through data based statistical modeling, how the concepts or constructs of sensor effectiveness, usability of information, mental workload, situation awareness and teamwork relates to each other and to the operative performance in a fourship of fighter pilots. Through the use of structural equation modeling, ad modum LISREL, a statistical model that describes how the operators’ functional state mediates the effects between technical system oriented variables, was developed. The constructs used in the modeling process have received widespread scientific and operational attention. They have also been identified as multi-dimensional. Many different ways of measuring them have been developed in the scientific community, and the thesis focuses on the next step, i.e. how do these higher order constructs relate to each other in something as multi-dimensional as human activity in real situations? A comprehensive human factors related dataset was collected in a large simulation based acquisition study that examined the requirements and properties of aircraft radar systems. The dataset contains 308 simulated engagements with data from four pilots each, i.e. 1232 cases in a database with 24 variables, generated by 37 pilots. The collected data and the resulting models thus summarizes more than 700 hours of experienced pilots’ complex behavior in an operationally valid environment, and in a way that is of theoretical interest as well as of importance in system development processes. The data thus comes from a real world study of complex processes in a dynamic context, although from a simulator. The thesis is a case example of modern ecologically valid experimental psychology. The data collection does not represent a classical experimental setup, but instead demonstrates methodological needs and considerations for human factors practitioners when working in system development studies. The fact that parts of the used data are classified has not affected the models and scientific conclusions, although the practical findings have been partly circumscribed in the presentation. As a result of the statistical modeling effort, a structural equation model of how the chosen constructs relate to each other, and mediate effects between technical measures by a model of the operator, is proposed. Simplicity of the model was the goal, and based on former experiences and findings, a simplex structure was hypothesized. The final model shows that the covariances between the 24 measures can be explained by a quasi-simplex structure of seven factors. / Statistiskt och matematiskt underbyggda slutsatser kring ett systems operativa användbarhet är kritiska i systemutvecklingsprocesser i mångmiljardklassen. Även om det är uppenbart att människan är den viktigaste och mest kritiska komponenten i många system har det ofta varit svårt för forskare inom området Människa System Interaktion (MSI) att uttrycka mänskliga faktorer på ett statistiskt och matematiskt strikt sätt. Den här avhandlingen visar och kvantifierar hur koncepten sensoreffektivitet, användbarhet hos information, mental arbetsbelastning, situationsmedvetande, samarbete och operativ prestation relaterar tilll varandra i en fyrgrupp militära flygförare genom modellering baserad på empiriska data. Genom att använda strukturella ekvationsmodeller, här m.h.a. LISREL, visas en statistisk modell av hur variabler som beskriver operatörernas förmåga att prestera medierar effekter mellan mer systemorienterade variabler. De koncept eller faktorer som används i modelleringsprocessen har rönt stor vetenskaplig och operativ uppmärksamhet. De har också identifierats som mångdimensionella och inom forskningsområdet har en stor mängd olika mätmetoder utvecklats. Avhandlingen fokuserar på vad som sker i steget efter datainsamling, d.v.s. hur kan dessa faktorer relateras till varandra i något så mångdimensionellt som mänsklig aktivitet i verkliga situationer? En omfattande beteendevetenskaplig datamängd samlades in under en stor simuleringsbaserad anskaffningsstudie som studerade krav för en ny flygplansradar. Databasen innehåller data från 308 simulerade flygföretag, med data från fyra flygförare per företag, d.v.s. 1232 rader i databasen med 24 variabler på varje rad, vilka genererats av 37 flygförare. Den insamlade datamängden sammanfattar mer än 700 timmar av erfarna flygförares arbete och prestation i en operativt relevant miljö på ett sätt som är både teoretiskt intressant och användbart i en systemutvecklingsprocess. Data kommer från en studie i verkligheten – även om verkligheten var simulerad – som handlade om komplexa processer i en dynamisk kontext. Avhandlingen är i sig ett exempel på en modern experimentalpsykologisk ansats som är giltig och användbar för tillämpade studier. Datainsamlingen representerar inte en klassisk experimentalpsykologisk ansats utan beskriver istället metodologiska behov och avvägningar som en MSI-forskare möter under arbete med systemutveckling. En delmängd av den insamlade datamängden är sekretessbelagd, vilket inte har påverkat modellerna eller de vetenskapliga slutsatserna, men vissa praktiska slutsatser har dock utelämnats. Resultatet från modellutvecklingen är en strukturell ekvationsmodell som beskriver hur de utvalda koncepten relaterar till varandra och därigenom beskrivs relationen mellan tekniska mått m.h.a. en modell av flygförarna. Enkelhet och överblickbarhet i modellen var en del av målsättningen och baserat på tidigare erfarenheter användes en simplex struktur under modellkonceptualiseringsfasen. Den slutgiltiga modellen visar att kovarianserna mellan de 24 variablerna i databasen kan förklaras m.h.a. en kvasi-simplex struktur med sju faktorer.
269

A DAE Formulation for Multi-Zone Thermodynamic Models and its Application to CVCP Engines

Öberg, Per January 2009 (has links)
In the automotive area there are ever increasing demands from legislators and customers on low emissions and good fuel economy. In the process of developing and investigating new technologies, that can meet these demands, modeling and simulation have become important as standard engineering tools. To improve the modeling process new concepts and tools are also being developed. A formulation of a differential algebraic equation (DAE) that can be used for simulation of multi-zone in-cylinder models is extended and analyzed. Special emphasis is placed on the separation between thermodynamic state equations and the thermodynamic properties. This enables implementations with easy reuse of model components and analysis of simulation results in a structured manner which gives the possibility to use the formulation in a large number of applications. The introduction and depletion of zones are handled and it is shown that the DAE formulation has a unique solution as long as the gas model fulfills a number of basic criteria. Further, an example setup is used to validate that energy, mass, and volume are preserved when using the formulation in computer simulations. In other words, the numerical solution obeys the thermodynamic state equation and the first law of thermodynamics, and the results are consistent and converge as tolerances are tightened. As example applications, the DAE formulation is used to simulate spark ignited SI and Diesel engines as well as simple control volumes and 1-dimensional pipes. It is thus shown that the DAE formulation is able to adapt to the different requirements of the SI and Diesel engine models. An interesting application is the SI engine with continuously variable cam phasing (CVCP), which is a technology that reduces the fuel consumption. It influences the amount of air and residual gases in the engine in a non trivial manner and this SI application is used to evaluate three control oriented models for cylinder air charge and residual mass fraction for a CVCP-engine both for static and transient conditions. The models are: a simple generalized flow restriction model created with physical insight and two variants of a model that is based on an energy balance at intake valve closing (IVC). The two latter models require measurement of cylinder pressure and one also requires an air mass flow measurement. Using the SI model as reference it is shown that transients in cam positions have a large impact on air charge and residual mass fraction, and the ability of the models to capture these effects is evaluated. The main advantages of the generalized flow restriction model are that it is simple and does not require measurement of the cylinder pressure but it is also the model with the largest errors for static operating points and highest sensitivity in transients. The two models that use an energy balance at IVC both handle the transient cycles well. They are, however, sensitive to the temperature at IVC. For static cycles it is therefore advantageous to use the model with air mass flow measurement since it is less sensitive to input data. During transients however, if the external measurement is delayed, it is better to use the model that does not require the air mass flow. The conclusion is that the DAE formulation is a flexible, robust, tool, and that it is well suited for multi-zone in-cylinder models as well as models for manifolds and pipes outside the cylinder.
270

Reconfigurable and Broadband Circuits for Flexible RF Front Ends

Ahsan, Naveed January 2009 (has links)
Most of today’s microwave circuits are designed for specific function and special need. There is a growing trend to have flexible and reconfigurable circuits. Circuits that can be digitally programmed to achieve various functions based on specific needs. Realization of high frequency circuit blocks that can be dynamically reconfigured to achieve the desired performance seems to be challenging. However, with recent advances in many areas of technology these demands can now be met. Two concepts have been investigated in this thesis. The initial part presents the feasibility of a flexible and programmable circuit (PROMFA) that can be utilized for multifunctional systems operating at microwave frequencies. Design details and PROMFA implementation is presented. This concept is based on an array of generic cells, which consists of a matrix of analog building blocks that can be dynamically reconfigured. Either each matrix element can be programmed independently or several elements can be programmed collectively to achieve a specific function. The PROMFA circuit can therefore realize more complex functions, such as filters or oscillators. Realization of a flexible RF circuit based on generic cells is a new concept. In order to validate the idea, two test chips have been fabricated. The first chip implementation was carried out in a 0.2μm GaAs process, ED02AH from OMMICTM. The second chip was implemented in a standard 90nm CMOS process. Simulated and measured results are presented along with some key applications such as low noise amplifier, tunable band pass filter and a tunable oscillator. The later part of the thesis covers the design and implementation of broadband RF front-ends that can be utilized for multistandard terminals such as software defined radio (SDR). The concept of low gain, highly linear frontends has been presented. For proof of concept two test chips have been implemented in 90nm CMOS technology process. Simulated and measurement results are presented. These RF front-end implementations utilize wideband designs with active and passive mixer configurations. We have also investigated narrowband tunable LNAs. A dual band tunable LNA MMIC has been fabricated in 0.2μm GaAs process. A self tuning technique has been proposed for the optimization of this LNA.

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