This report is an outcome of a master degree project at Linköpings University in co-operation with Micronic Laser Systems AB. The purpose with this master degree project was to investigate how to implement a receiver in a data transfer system. The system consists of several data channels, where every channel consists of three parts: driver, transmission lines and receiver. The driver send low amplitude differential signals via the transmission lines to the receiver that amplifies and converts it to a single-ended signal. The receiver has to be fast and be able to feed an output signal with high voltage swing.

Normally the operational amplifier is used as a component in active filter design. The goal for future components in filter design is large bandwith and the use of low supply voltages. The use of current-mode instead of voltage-mode circuits gets a step closer to the required performance. A component that use current as the signal conveying part is the current conveyor. In this report a comparative study between two current conveyor structures of second generation (CCII) is performed.

This report present the design and manufacturing of a wide-band driver amplifier placed in radar module for airborne applications. The major goals for the amplifier were a high efficiency and to deliver a predefined output power. To reach the second goal an additional preamplifier had to be constructed. The amplifiers were constructed in three steps: Design and Layout in the software Microwave Office, Mounting components and Verification. The driver amplifier was decided to be a push pull configuration consisting of two parallel transistors biased in class AB.

Softube has developed DSP-card and software for simulation of the sound of old tube amplifiers. The purpose with this thesis is to design a compact amplifier with high power to function together with the DSP-card and build a unit that can replace several other guitar amplifiers. The advantages with that kind of solution could be that it would be cheaper, easier to carry and easier to stor than the real amplifiers. The amplifier that has been designed is of class D type with digital PWM modulator. There is several types of amplifier modules on the market that use analog input signal, but if one of them would be used a D-A converter is needed on the DSP card.

A current conveyor is an active building block that can be used to implement most active and passive components. It differs from the operation amplifier in that it uses current instead of voltage. The current conveyor also has significantly higher voltage gain over a broader frequency range. To simplify the construction of analogue circuits and increase the construction efficiency it is desirable to use a top-down methodology. This means that the whole system is partitioned into a hierarchy of subsystems.

The last few decades the development in the field of electronics has been huge. The components performance gets better at the same time as the manufacturing cost decreases. Many of the design moments that have to be done, are done automatically today, but it can get better. Especially for analog circuit design.At Electronic System in Linköpings universitet, research is in progress to develop a tool that can design analog circuits in reasonable time. It means that it has to size the components (transistors, resistances, capacitances etc), so that the circuit can fulfill the performance requirements.

The purpose with the report is to show that it is possible to design a class-D amplifier, using a programmable FPGA mounted on a developing card from Xess and a H-bridge. The FPGA was programmed in VHDL which is the language the software from Xilinx use to implement a logical function into the FPGA The logical function corresponds to a modeling of the music signal and the modeling can be described as a comparator which compare the music signal with a triangle wave and as a out signal produce a pulse width modulated (PWM) signal. The report is also a review and evaluating of two different modulating technologies, AD- modeling and BD-modeling. A detailed part about how the H-bridge was designed and how it works. The result of this project is a working audio amplifier to a significant lower price than the products in todays market..

In this report we describe an adaptive simulated annealing method for sizing the devices in analog circuits. The motivation for use an adaptive simulated annealing method for analog circuit design are to increase the efficiency of the design circuit. To demonstrate the functionality and the performance of the approach, an operational transconductance amplifier is simulated. The circuit is modeled with symbolic equations that are derived automatically by a simulator..

The forestry companies? operational planning process is these days dependent on reliable, efficient and user-friendly computer-based support systems. This study is an evaluation of Holmen Skog's current computer-based systems. The aim of this study is to: ? investigate the work pattern of the production managers when using the information system to plan the harvesting operation; ? investigate the efficiency and user friendliness of the information system with the different work patterns and to find the strengths, weaknesses and bottlenecks in the current system; ? find out if the type of object, the volume, the area of the harvesting object affects the time and work pattern; ? examine how this type of study is met by the employees and what factors that is critical to avoid feelings of intrusion. The conclusions of the study were: ? there is a large variation between the work patterns of the production managers and the time spend to perform the operational planning; ? the mainframe computer system used by Holmen Skog is clear, has short response times, is robust and conveys relevant information; ? the computer systems are however divided in many subsystems.

This paper describes a method for wireless energy transfer via near-field electromagnetic inductionthat is inexpensive, simple and can be applied to almost any type of system, regardless of size andenergy demands.The method uses a primary unit consisting of an oscillator, amplifier and inductive coil thattransfers energy to a secondary unit consisting of a coil, rectifier and voltage regulator. Two typesof oscillators and several amplifier designs were realized and evaluated together with a multitudeof flat coils of both monofilar and bifilar type.The results show that it is important to use an oscillator whose frequency is dependent on theinductance of the connected transmission coil, such as the Colpitts oscillator. This is preferable toan oscillator with a preset frequency, such as a Schmitt-trigger oscillator..

Lärare använder sig av olika metoder för att hjälpa studenter att utveckla de verktyg de behöver för att lära sig engelska, eller något annat ämne. En metod här är muntlig feedback, som används för att uppmuntra elever eller korrigera dem när de utför språkliga fel. Vårt mål med detta examensarbete är därför att undersöka vilka typer av muntlig feedback som kan hittas i ett klassrum där man lär sig engelska som främmande språk och vilka attityder som både lärare och studenter kan ha gentemot muntlig feedback. Tre typer av undersökningsmetoder har använts: observationer, intervjuer och enkäter. Resultatet visar på att studenter förhåller sig positivt till muntlig feedback i klassrummet, särskilt explicit corrective feedback.

Starting in January 2007, capital adequacy of internationally active banks will be regulated by the new Basel Capital Accord, International Convergence of Capital Measurement and Capital Standards ? a revised framework, [Basel II]. The framework introduces for the first time minimum capital requirements for operational risk and encourages market discipline of capital adequacy by initiating requirements for public disclosure of quantitative and qualitative information on operational risk exposure. This thesis examines the nature, definition, management and public disclosure of operational risk in Scandinavian banks based on regulations and recommendations presented in Basel II. We find that the models currently available for addition of operational risk to the capital requirement do not reflect actual operational risk exposure of banks.

AimThe purpose of the survey was to see how students relate to feedback in physical education. The aim was also to find out how students like to receive feedback (written, oral or timing). The survey will also specify what kind of feedback the teacher provides.QuestionsHow do students react to feedback?How do students want to receive feedback?What kind of feedback do the students receive during the lessons in physical education?MethodThe method used in this study was qualitative group interviews with an observation before the interviews. The school that participated was my placement school during my teachers program and it is located in a suburb south of Stockholm.

Syftet med föreliggande studie var att få en större förståelse för hur några lärare upplevde feedback i sin arbetssituation. De frågeställningar som studien baserades på var: Vilken inverkan har feedback på arbetsglädjen på en arbetsplats, sett ur ett medarbetarperspektiv? På vilket sätt har denna feedback en relation till lärarnas utveckling av sin egen feedbackkompetens? Det metodologiska angreppssättet var en semistrukturerad intervjuguide. Urvalet bestod av åtta lärare. Intervjuerna varade 20-35 minuter.

This paper describes a method for wireless energy transfer via near-field electromagnetic inductionthat is inexpensive, simple and can be applied to almost any type of system, regardless of size andenergy demands.The method uses a primary unit consisting of an oscillator, amplifier and inductive coil thattransfers energy to a secondary unit consisting of a coil, rectifier and voltage regulator. Two typesof oscillators and several amplifier designs were realized and evaluated together with a multitudeof flat coils of both monofilar and bifilar type.The results show that it is important to use an oscillator whose frequency is dependent on theinductance of the connected transmission coil, such as the Colpitts oscillator. This is preferable toan oscillator with a preset frequency, such as a Schmitt-trigger oscillator..