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Topological Photonic Lattices / Topologiska fotoniska gitterXu, Zesheng January 2022 (has links)
Topological Photonics is a rapidly growing field which explores the ideas of topological invariants adapted from condensed matter physics to optical systems. Thanks to integrated photonics platforms, the evolution of light in nanoscale photonic lattices can enable direct measurement of topological properties of the band-structure. In this degree project, we study the topological Anderson phase transition in disordered one-dimensional lattices, and probe distinct topological phases in photonic superlattices. In first part, we fabricate photonic lattices with different disorder strength, and observe the topological transition from trivial topological Anderson phase to non-trivial topological Anderson phase as the system disorder is increased. In second part, we focus on probing the Zak phase in photonic superlattices. We fabricate a superlattice system that utilizes either bulk excitation or edge excitation. We identify the trivial and non-trivial Zak phase using two methods: first, through reconstructing the intensity evolution in the edge waveguide, second, through calculating the beam displacement in the case of bulk excitation . In order to study the evolution of the light in the nano-scaled photonic lattices, we develop a novel technique: Loss-Induced Scattering Approach (LISA), which enables high fidelity reconstruction of the photonic state evolving in the lattice. / Topologisk fotonik är ett snabbt växande område som utforskar idéerna om topologiska invarianter anpassade från kondenserad materiens fysik till optiska system. Tack vare integrerade fotonikplattformar kan ljusutvecklingen i fotoniska gitter i nanoskala möjliggöra direkt mätning av topologiska egenskaper hos bandstrukturen. I detta examensarbete studerar vi den topologiska Anderson-fasövergången i oordnade endimensionella gitter, och undersöker distinkta topologiska faser i fotoniska supergitter. I den första delen tillverkar vi fotoniska gitter med olika störningsstyrka och observerar den topologiska övergången från trivial topologisk Anderson-fas till icke-trivial topologisk Anderson-fas när systemstörningen ökar. I den andra delen fokuserar vi på att sondera Zak-fasen i fotoniska supergitter. Vi tillverkar ett supergittersystem som använder antingen bulkexcitering eller kantexcitering. Vi identifierar den triviala och icke-triviala Zak-fasen med två metoder: för det första genom att rekonstruera intensitetsutvecklingen i kantvågledaren, för det andra genom att beräkna strålens förskjutning vid bulkexcitation. För att studera utvecklingen av ljuset i de nanoskalade fotoniska gittren, utvecklar vi en ny teknik: Loss-Induced Scattering Approach (LISA), som möjliggör högtrohetsrekonstruktion av det fotoniska tillståndet som utvecklas i gittret.
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Integration and Packaging Concepts for Infrared Bolometer ArraysDecharat, Adit January 2009 (has links)
<p> </p><p>Infrared (IR) imaging devices based on energy detection has shown a dramatic development in technology along with an impressive price reduction in recent years. However, for a low-end market as in automotive applications, the present cost of IR cameras is still the main obstacle to broadening their usage. Ongoing research has continuously reduced the system cost. Apart from decreasing the cost of infrared optics, there are other key issues to achieve acceptable system costs, including wafer-level vacuum packaging of the detectors, low vacuum level operation, and the use of standard materials in the detector fabrication. This thesis presents concepts for cost reduction of low-end IR cameras.</p><p> The thesis presents a study of detector performance based on the thermal conductance design of the pixel. A circuit analog is introduced to analyze the basic thermal network effect from the surrounding environment on the conductance from the pixel to the environment. A 3D simulation model of the detector array conductance has been created in order to optimize the performance of the arrays while operated in low vacuum. In the model, Fourier's law of heat transfer is applied to determine the thermal conductance of a composite material pixel. The resulting thermal conductance is then used to predict the performance of the detector array in low vacuum.</p><p> The investigations of resist as the intermediate bonding material for 3D array integration are also reported in the thesis. A study has been made of the nano-imprint resists series mr-I 9000 using a standard adhesive wafer bonding scheme for thermosetting adhesives. Experiments have been performed to optimize the thickness control and uniformity of the nano-imprint resist layer. The evaluation, including assessment of the bonding surface uniformity and planarizing ability of topographical surfaces, is used to demonstrate the suitability of this resist as sacrificial material for heterogeneous detector array integration<em>. </em><em></em></p><p> Moreover, the thesis presents research in wafer-level packaging performed by room temperature bonding. Sealing rings, used to create a cavity, are manufactured by electroplating. The cavity sealing is tested by liquid injection and by monitoring the deflection of the lid membrane of the cavities. A value for the membrane deflection is calculated to estimate the pressure inside the cavities. </p>
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Design and implementation of controller for robotic manipulators using Artificial Neural NetworksChamanirad, Mohsen January 2009 (has links)
<p>In this thesis a novel method for controlling a manipulator with arbitrary number of Degrees of freedom is proposed, the proposed method has the main advantages of two common controllers, the simplicity of PID controller and the robustness and accuracy of adaptive controller. The controller architecture is based on an Artificial Neural Network (ANN) and a PID controller.</p><p>The controller has the ability of solving inverse dynamics and inverse kinematics of robot with two separate Artificial Neural Networks. Since the ANN is learning the system parameters by itself the structure of controller can easily be changed to</p><p>improve the performance of robot.</p><p>The proposed controller can be implemented on a FPGA board to control the robot in real-time or the response of the ANN can be calculated offline and be reconstructed by controller using a lookup table. Error between the desired trajectory path and the path of the robot converges to zero rapidly and as the robot performs its tasks the controller learns the robot parameters and generates better control signal. The performance of controller is tested in simulation and on a real manipulator with satisfactory results.</p>
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Printed electronics : Implementation of WORM memory in a RF-antitheft systemHammarling, Krister January 2009 (has links)
<p>Current printable memory technology are not suited for mass produc‐tion. With new inexpensive printed memory, it will be possible to manufacture cheap surveillance tags that are capable to tell the user if something has happened within a timeline. This project is within the ITC FrameProgram 7 founded project PriMeBits. The goal is to imple‐ment a write once read many memory (WORM) onto an RF‐tag together with a sensor that can sense wetness, which can be detected by EAS antitheft systems. Pre researches have been done in the fields printed capacitance, coils and WORMs, all printed with silver ink. Before implementation of a WORM onto a tag simulations and laboratory tests with adjustable resistances were made. Two different circuit models are simulated and tested. When connected to a tag and the WORM is un‐programmed, the EAS system should not trigger an alarm. But if the WORM is programmed by the sensor, the alarm should trigger. Results show that capacitances and WORMs are printable with this technique but coils are not due to high inner resistance. The simulations show that a tag built as an LCCR‐circuit is the best choice. This is also confirmed with tests done with real resistors. With WORMs connected to a tag the results show that approximately 70% of them work as intended, this is because the WORMs as of now are not completely developed. The conclusion of this project is that it is possible to implement a WORM onto a tag with further research, to make an inexpensive surveillance tag.</p> / PriMeBits
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Theory and Applications of Coupling Based Intensity Modulated Fibre-Optic SensorsJason, Johan January 2008 (has links)
<p>Optical fibre sensors can be used to measure a wide variety of properties. In some cases they have replaced conventional electronic sensors due to their possibility of performing measurements in environments suffering from electromagnetic disturbance, or in harsh environments where electronics cannot survive. In other cases they have had less success mainly due to the higher cost involved in fibre-optic sensor systems. Intensity modulated fibre-optic sensors normally require only low-cost monitoring systems principally based on light emitting diodes and photo diodes. The sensor principle itself is very simple when based on coupling between fibres, and coupling based intensity modulated sensors have found applications over a long time, mainly within position and vibration sensing. In this thesis new concepts and applications for intensity modulated fibre-optic sensors based on coupling between fibres are presented. From a low-cost and standard component perspective alternative designs are proposed and analyzed in order to find improved performance. The development of a sensor for an industrial temperature sensing application, involving aspects on multiplexing and fibre network installation, is presented. Optical time domain reflectometry (OTDR) is suggested as an efficient technique for multiplexing several coupling based sensors, and sensor network installation with blown fibre in micro ducts is proposed as a flexible and cost-efficient alternative to traditional cabling. A new sensor configuration using a fibre to a multicore fibre coupling and an image sensor readout system is proposed. With this system a high-performance sensor setup with a large measurement range can be realised without the need for precise fibre alignment often needed in coupling based sensors involving fibres with small cores. The system performance is analyzed theoretically with complete system simulations on different setups. An experimental setup is made based on standard fibre and image acquisition components, and differences from the theoretical performance are analyzed. It is shown that sub-µm accuracy should be possible to obtain, being the theoretical limit, and it is further suggested that the experimental performance is mainly related to two error sources: core position instability and differences between the real and the expected optical power distribution. Methods to minimize the experimental error are proposed and evaluated.</p>
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Amplification circuits based on electrochemical transistorsKhan, Zia Ullah January 2009 (has links)
<p>Electrochemical Transistor(ECT) was reported by David Nilsson in 2002. Later,its dimensios were specified and a SPICE model was developed.</p><p>The main purpose of this diploma work is to check the performance of electrochemical transistors in amplifier circuits. Simple amplifier circuits were simulated using SPICE model of ECT. Lateral and Vertical structures of electrochemical transistors were patterned on orgacon sheet(provided by AGFA),with various electrolytes(EG010,MS-HEC & MS-L). Characteric curves and time responses of these transistors were studied and then were then used as an active component in single amplifier circuits. Screen printed ECT's were also checked with the best available electrolyte. Behaviour of self made and screen printed ECT's were compared on the basis of on-off ratio,slew rate,frequency response and gain. Screen printed transistors showed promising results having less deterioration with time but till an an input signal frequency of 2Hz only. Mismatch with simulation results and Shockley's equation were other findings after data analysis.</p><p><img src="file:///C:/DOCUME%7E1/zia/LOCALS%7E1/Temp/moz-screenshot.jpg" /><img src="file:///C:/DOCUME%7E1/zia/LOCALS%7E1/Temp/moz-screenshot-1.jpg" /></p>
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Design Space Exploration of Time-Multiplexed FIRFilters on FPGAsAlam, Syed Asad January 2010 (has links)
<p>FIR (Finite-length Impulse Response) filters are the corner stone of many signalprocessing devices. A lot of research has gone into their development as wellas their effective implementation. With recent research focusing a lot on powerconsumption reduction specially with regards to FPGAs, it was found necessaryto explore FIR filters mapping on FPGAs.</p><p>Time multiplexed FIR filters are also a good candidate for examination withrespect to power consumption and resource utilization, for example when implementedin Field Programmable Gate Arrays (FPGAs). This is motivated by thefact that the usable clock frequency often is higher compared to the required datarate. Current implementations by, e.g., Xilinx FIR Compiler suffer from highpower consumption when the time multiplexing factor is low. Further, it needs tobe investigated how exploiting coefficient symmetry, scaling the coefficients andincreasing the time-multiplexing factor influences the performance.</p>
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Frame Allocation and Scheduling for Relay Networks in the LTE Advanced StandardRoth, Stefan January 2010 (has links)
<p>The use of relays is seen as a promising way to extend cell coverage and increase rates in LTE Advanced networks. Instead of increasing the number of base stations (BS), relays with lower cost could provide similar gains. A relay will have a wireless link to the closest BS as only connection to the core network and will cover areas close to the cell edge or other areas with limited rates.</p><p>Performing transmissions in several hops (BS-relay & relay-user) requires more radio resources than using direct transmission. This thesis studies how the available radio resources should be allocated between relays and users in order to maximize throughput and/or fairness. Time and frequency multiplexed backhaul is investigated under a full buffer traffic assumption. It is shown that the system will be backhaul limited and that the two ways of multiplexing will perform equally when maximising throughput and/or fairness. The analysis results in a set of throughput/fairness suboptimal solutions, dependant on how many relays are used per cell. The results are verified by simulations, which also show the limiting effects on throughput caused by interference between relays.</p><p>It is also analysed how the resource allocation should be done given non-fullbuffer traffic. A resource allocation that minimises packet delay given a certain number of relays per cell is presented. The analysis is based on queuing theory.</p><p>Finally some different schedulers and their suitability for relay networks are discussed. Simulation results are shown, comparing the throughput and fairness of Round Robin, Weighted Round Robin, Proportional Fairness and Weighted Proportional Fairness schemes. It is shown that allocating the resource among the relays according to the number of users served by the relays improves the fairness.</p>
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A 65nm, Low Voltage, Fully Differential, SC Programmable Gain Amplifier for Video AFE / En 65 nm, fullt differentiell, programmerbar SC-förstärkare för video-AFE med låg matningspänningAamir, Syed Ahmed January 2010 (has links)
<p>Due to rapid growth of home entertainment consumer market, video technology has been continuously pushed to deliver sharper pictures with higher resolution. This has brought about stringent requirements on the video analog front end, which often coupled with the low power and low voltage regulations had to deal with short channel effects of the deep submicron CMOS processes.</p><p>This thesis presents the design of a fully differential programmable gain amplifier, as a subcircuit of a larger video digitizing IC designed at division of Electronic Systems. The switched capacitor architecture of the PGA does not only buffer the signal, but performs compensation for the sync-tip of analog video signal.</p><p>The pseudo differential OTA eliminates tail current source and maintains high signal swing and has efficient common mode feedforward mechanism. When coupled with a similar stage provides inherent common moode feedback without using an additional SC-CMFB block.</p><p>The PGA has been implemented using a 65 nm digital CMOS process. Expected difficulties in a 1.2 V OTA design make themselves evident in 65 nm, which is why cascaded OTA structures were inevitable for attaining gain specification of 60 dB. Nested Miller compensation with a pole shifting source follower, stabilizes the multipole system. The final circuit attains up to 200 MHz bandwidth and maintains high output swing of 0.85 V. High slew rate and good common mode and power supply rejection are observed. Noise requirements require careful design of input differential stage. Although output source follower stabilized the system, it reduces significant bandwidth and adds to second order non-linearity.</p>
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Konstruktion av Industriellt Vibrationsmätningssystem med signalbehandling baserad på Digitala Vågfilter av Lattice-struktur / Construction of Industrial Vibration Measurement System with signal-processing based on Lattice Wave Digital filter structuresTegelid, Simon, Åström, Jonas January 2010 (has links)
<p>In this bachelor thesis a complete prototype of an industrial vibration measurement platform has been developed. By measuring a number of variables such as acceleration, temperature and speed conclusions can be drawn on machinery health. The aim is to evaluate hardware and software solutions for a possible future product. Based on a requirement specification a proper hardware design has be developed. The hardware consists of a four-layer PCB with an ARM Cortex-M3 microcontroller and about 250 other components. The PCB was designed, assembled, tested and finally housed in a box. Measures have been taken to protect the prototype against external disturbances such as inappropriate supply voltages and transients on the input stages.Software has been written for the microcontroller to perform the various measurements required by the prototype. These include RMS, integration and filtering. Special attention was paid to the latter by implementing filters based on lattice wave digital structures. This structure results in a very efficient implementation. Consideration is taken to be able to generate arbitrary filters independent of the characteristics and design method. To save time the microcontroller implements all the algorithms without any floating point numbers.Furthermore, both hardware and software are adapted for future industrial use. The finished prototype supports a number of communication interfaces in which Modbus (RS-485) and current loop communication can be mentioned.The final result is a very good performing platform with strong future potential.The work was commissioned by the consulting firm Syncore Technologies AB at their office in Mjärdevi, Linköping. The project has, in total, taken 10 weeks and occurred during spring 2010.In this bachelor thesis a complete prototype of an industrial vibration measurement platform has been developed. By measuring a number of variables such as acceleration, temperature and speed conclusions can be drawn on machinery health. The aim is to evaluate hardware and software solutions for a possible future product. Based on a requirement specification a proper hardware design has be developed. The hardware consists of a four-layer PCB with an ARM Cortex-M3 microcontroller and about 250 other components. The PCB was designed, assembled, tested and finally housed in a box. Measures have been taken to protect the prototype against external disturbances such as inappropriate supply voltages and transients on the input stages.Software has been written for the microcontroller to perform the various measurements required by the prototype. These include RMS, integration and filtering. Special attention was paid to the latter by implementing filters based on lattice wave digital structures. This structure results in a very efficient implementation. Consideration is taken to be able to generate arbitrary filters independent of the characteristics and design method. To save time the microcontroller implements all the algorithms without any floating point numbers.Furthermore, both hardware and software are adapted for future industrial use. The finished prototype supports a number of communication interfaces in which Modbus (RS-485) and current loop communication can be mentioned.The final result is a very good performing platform with strong future potential.The work was commissioned by the consulting firm Syncore Technologies AB at their office in Mjärdevi, Linköping. The project has, in total, taken 10 weeks and occurred during spring 2010.</p>
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