This work presents a robust dual band local positioning system (LPS) working in the 2.4GHz and 5.8GHz industrial science medical (ISM) bands. Position measurement is based on the frequency-modulated continuous wave (FMCW) radar approach, which uses radio frequency (RF) chirp signals for propagation time and therefore distance measurements. Contrary to state of the art LPS, the presented system uses data from both bands to improve accuracy, precision and robustness. A complete system prototype is designed consisting of base stations and tags encapsulating most of the RF and analogue signal processing in custom integrated circuits. This design approach allows to reduce size and power consumption compared to a hybrid system using off-the-shelf components. Key components are implemented using concepts, which support operation in multiple frequency bands, namely, the receiver consisting of a low noise amplifier (LNA), mixer, frequency synthesizer with a wide band voltage-controlled oscillator (VCO) having broadband chirp generation capabilities and a dual band power amplifier. System imperfections occurring in FMCW radar systems are modelled. Effects neglected in literature such as compression, intermodulation, the influence of automatic gain control, blockers and spurious emissions are modeled. The results are used to derive a specification set for the circuit design. Position estimation from measured distances is done using an enhanced version of the grid search algorithm, which makes use of data from multiple frequency bands. The algorithm is designed to be easily and efficiently implemented in embedded systems. Measurements show a coverage range of the system of at least 245m. Ranging accuracy in an outdoor scenario can be as low as 8.2cm. Comparative dual band position measurements prove an effective outlier filtering in indoor and outdoor scenarios compared to single band results, yielding in a large gain of accuracy. Positioning accuracy in an indoor scenario with an area of 276m² can be improved from 1.27m at 2.4GHz and 1.86m at 5.8GHz to only 0.38m in the dual band case, corresponding to an improvement by at least a factor of 3.3. In a large outdoor scenario of 4.8 km², accuracy improves from 1.88m at 2.4GHz and 5.93m at 5.8GHz to 0.68m with dual band processing, which is a factor of at least 2.8. / Die vorliegende Arbeit befasst sich mit dem Entwurf eines robusten lokalen Positionierungssystems (LPS), welches in den lizenzfreien Frequenzbereichen für industrielle, wissenschaftliche und medizinische Zwecke (industrial, scientific, medical, ISM) bei 2,4GHz und 5,8GHz arbeitet. Die Positionsbestimmung beruht auf dem Prinzip des frequenzmodulierten Dauerstrichradars (frequency modulated continuous wave, FMCW-Radar), welches hochfrequente Rampensignale für Laufzeitmessungen und damit Abstandsmessungen benutzt. Im Gegensatz zu aktuellen Arbeiten auf diesem Gebiet benutzt das vorgestellte System Daten aus beiden Frequenzbändern zur Erhöhung der Genauigkeit und Präzision sowie Verbesserung der Robustheit. Ein Prototyp des kompletten Systems bestehend aus Basisstationen und mobilen Stationen wurde entworfen. Fast die gesamte analoge hochfrequente Signalverarbeitungskette wurde als anwendungsspezifische integrierte Schaltung realisiert. Verglichen mit Systemen aus Standardkomponenten erlaubt dieser Ansatz die Miniaturisierung der Systemkomponenten und die Einsparung von Leistung. Schlüsselkomponenten wurden mit Konzepten für mehrbandige oder breitbandige Schaltungen entworfen. Dabei wurden Sender und Empfänger bestehend aus rauscharmem Verstärker, Mischer und Frequenzsynthesizer mit breitbandiger Frequenzrampenfunktion implementiert. Außerdem wurde ein Leistungsverstärker für die gleichzeitige Nutzung der beiden definierten Frequenzbänder entworfen. Um Spezifikationen für den Schaltungsentwurf zu erhalten, wurden in der Fachliteratur vernachlässigte Nichtidealitäten von FMCW-Radarsystemen modelliert. Dazu gehören Signalverzerrungen durch Kompression oder Intermodulation, der Einfluss der automatischen Verstärkungseinstellung sowie schmalbandige Störer und Nebenschwingungen. Die Ergebnisse der Modellierung wurden benutzt, um eine Spezifikation für den Schaltungsentwurf zu erhalten. Die Schätzung der Position aus gemessenen Abständen wurde über eine erweiterte Version des Gittersuchalgorithmus erreicht. Dieser nutzt die Abstandsmessdaten aus beiden Frequenzbändern. Der Algorithmus ist so entworfen, dass er effizient in einem eingebetteten System implementiert werden kann. Messungen zeigen eine maximale Reichweite des Systems von mindestens 245m. Die Genauigkeit von Abstandsmessungen im Freiland beträgt 8,2cm. Positionsmessungen wurden unter Verwendung beider Einzelbänder durchgeführt und mit den Ergebnissen des Zweiband-Gittersuchalgorithmus verglichen. Damit konnte eine starke Verbesserung der Positionsgenauigkeit erreicht werden. Die Genauigkeit in einem Innenraum mit einer Grundfläche von 276m² kann verbessert werden von 1,27m bei 2,4GHz und 1,86m bei 5,8GHz zu nur 0,38m im Zweibandverfahren. Das entspricht einer Verbesserung um einen Faktor von mindestens 3,3. In einem größeren Außenszenario mit einer Fläche von 4,8 km² verbessert sich die Genauigkeit um einen Faktor von mindestens 2,8 von 1,88m bei 2,4GHz und 5,93m bei 5,8GHz auf 0,68m bei Nutzung von Daten aus beiden Frequenzbändern.

The cost of packets or pallets handling at the studied freight company has increased considerable through the years due to increase in online shopping. As a result of this, the company has tried different methods of processing packets and pallets at the warehouse without effective result. The primary aim of the study is to analyze communication and collaboration of information in the warehouse and come up with a possible improvement suggestion to the multinational freight company. The result from the analysis shows the weak points in information sharing between different areas of warehouse operations of the multinational freight company. The outcome of the study recommends use of information technology such as Radio Frequency Identification and Wireless Sensor Network. The recommendation will allow extension of information sharing to all processes involved in packets or pallets handling at the warehouse.

This assignment was given by Nordic Semiconductor. In this project a radio frequency energy harvesting system able to harvest ambient power at 900 MHz (GSM) was simulated and designed. A Villard voltage multiplier, boost converter and power management circuit was implemented for the harvesting system. The intention was to implement a system which would give sufficient output power and voltage to supply a load (nRF52810) at all times. The nRF52810 is a power efficient multi protocol SoC made by Nordic Semiconductor. Since the power harvested by the antenna is of AC power, a recti er was needed. A Villard voltage multiplier was proposed as the most suitable application. It not only recti es the voltage, but the voltage doubles for every stage. A 2-stage Villard voltage multiplier was proposed with the advantage that in theory the output voltage should be four times higher in magnitude than the input voltage. There exists several other ways to boost a voltage, a voltage boost converter was combined with the Villard Voltage multiplier. According to calculations the boost converter should boost the voltage up to 2.3 V. Since the assumed power from the harvesting system may be lower than the power consumed by the load, a power managing circuit was also needed, which would avoid the load to drain the current from the storage element before the voltage level was sufficient. Different solutions for a power management circuit was proposed using different variations of MOSFETs. A real-life design was implemented, but the Villard voltage multiplier gave out a much lower e efficiency than expected from simulations. The output power of the VVM was too low to supply the load (nRF52810).

Radio astronomy, the survey and study of naturally occurring astronomical radio signals, is a challenging field in terms of engineering requirements. The typical astronomical signal of interest is incredibly faint, resulting in very low signal-to-noise ratios (SNRs) on the order of -30 dB or lower. To detect such signals, one must have an uncommonly low and stable receiver noise temperature, high gain through large aperture reflectors, and state-of-the-art signal processing algorithms. One must also be able to mitigate the effects of interference, the presence of which, even if extremely weak, can completely mask the faint astronomical signals of interest. To this end, this work presents the development of and results from a new broadband phased array feed (PAF) named the Focal L-Band Array for the Green Bank Telescope (FLAG). This instrument is able to form multiple simultaneous beams to survey a large patch of sky instantaneously, and has a minimum system noise temperature (Tsys) of 16.83 K. This PAF also has the potential to use spatial filtering techniques to place pattern nulls in the direction of interfering signals through the use of an orthogonal projection. This work will also present an improved method for computing an orthogonal projection operator, which is able to place a spatially broad null in the direction of a moving RFI source. A formal derivation of some detection and estimation theory properties for astronomical radio transients is also presented, which formalization is lacking within the astronomical community. This includes maximum-likelihood detectors and estimators and a Cramér Rao bound (CRB) analysis of astronomical transient parameters.

The use of technology in business process is gaining much attention, and many businesses today rely on technology as an important part of an efficient and effective way of meeting customers’ satisfaction. This study deals with the adoption of a proper and electronic means of tracking counterfeit drugs in the supply chain (distribution network) through the use of RFID technology. The case of the Ghanaian pharmaceutical group KAMA is considered. The main objective consists in finding out how the adoption of RFID technology would help tracking counterfeit drugs in the supply chain of this company and which benefits this could generate. Three research questions are stated and a qualitative approach is adopted. Field observation, a series of interviews with management and field workers of Kama as well as a questionnaire allowed collecting the data. The analysis of the data showed that RFID technology should be adopted by Kama to replace the present costly and relatively inefficient way of tracking counterfeit drugs. The motivation of workers to be trained on RFID as well as the company readiness to train employees represent major factors for adoption and implementation of RFID to track counterfeit drugs and hence contribute to increase the profit margin and improve Kama’s image on the market. Recommendations are finally made on the methodology to be adopted by Kama to implement and use RFID technology to track counterfeit drugs. / <p>Validerat; 20111202 (anonymous)</p>

This work deals with the transmission of optical radiation modulated by a radio frequency signal through an optical fiber. Furthermore, it describes the principles of communication and area coverage. It points out the practical use of components located in the communication chain of this system. Explains the functionality of the properties and the division of individual components. It introduces the benefits and limitations of this system. It further describes the creation of a topology suitable for laboratory measurement of RoF technology. Provides experimental measurement of C-band parameters. Indicates the possible use of RoF technology using a wireless optical link. A part of the work is also a sample laboratory protocol.

This thesis deals with RFID tags. In the first part of the thesis, the general overviews of the present-day RFID systems are presented. This part of the thesis is focused on the passive back-scatter UHF tags and the advantages of their application in supply chain usage. Subsequently, the electromagnetic simulators CST Microwave Studio and IE3D Zeland are described. These simulators were used to design loaded meander antennas. The antennas were designed for different materials and frequency bands of 867 MHz and 2.4 GHz. The designed antennas were made without as well as with the reflector which allows using the antennas in the vicinity of metals. Produced antennas were experimentally tested in the company METRA Blansko Inc, where one of the most significant characteristics of passive RFID tags – the read range was observed.

This thesis describes design of Simulator FM-CW range finders. It is choosing the optimal method of realization and inform about basic properties of continuous working radar. The work includes an analysis of errors in real rangefinder and a numerical estimate of the maximum error in real devices. Contains detailed block diagram of simulator FM-CW range-finder and computer simulation of function generator frequency modulated signal, demodulator. Further work includes the complete construction documents for the preparation and implementation of basic functional verification

Radio Frequency Identification (RFID) is a technology that facilitates wirelesscommunication. It is being widely used for access control purposes to aid administration ofservices. As with most wireless technologies, RFID has its challenges, due to its medium (radio waves) of communication, which makes it susceptible to signal interception and other possible attacks. The goal of this project is to investigate the insecurities in the implementation of the RFID system in transit (Storstockholms Lokaltrafik, Stockholm) systems. Due to the nature of the system, spatial information about consumers are accumulated over time thereby attracting some level of interests either legitimate or illegitimate, and raising some concerns. This thesis, takes into consideration the vulnerabilities of the RFID system and the potential security risks consumers of the system are exposed to, a detailed analysis is carried out on the existing infrastructure with the goal of exposing the shortcomings of the systems and proposing mitigating solutions. After an extensive work, seven (7) threats to privacy and security of RFID users were elaborated. Also discussion, about how different legislations around the world enforced data handling regulations in relation to commuter data, is carried out. Finally, most recent threats to consumer privacy are taken into consideration, as well as security in the mass transit field to put together a list of recommended safe practices. The work shows that RFID does pose significant threat to consumer privacy. One might argue that RFID has its benefits in its various implementations. However the fact remains that there are issues with regards to privacy that must to be addressed.

Ce projet de thèse porte sur le développement d'un dispositif instrumental basé sur les propriétés de non linéarité intrinsèques au matériau supraconducteur YBa2Cu3O7, qui restent jusqu'à présent peu explorées dans le régime radiofréquence (RF). Ceci, dans l'objectif de contrôler la commutation d'antennes supraconductrices ultrasensibles dédiées à l'Imagerie par Résonance Magnétique (IRM), de l'état supraconducteur à un état dissipatif. L'implémentation des antennes SHTC en imagerie permet d'atteindre les plus grandes sensibilités de détection observées actuellement en IRM à champ clinique, ce qui ouvre la voie au développement de l'imagerie moléculaire d'agents de contraste. Leur utilisation demeure cependant trop minoritaire et ce, entre autre, à cause de l'incompatibilité de la mise en œuvre des antennes YBa2Cu3O7 avec les méthodes de détection quantitative actuellement implémentées en imagerie moléculaire. Comme les techniques habituelles de découplage d'antennes ne sont pas transposables aux matériaux supraconducteurs, l'inactivation des antennes YBa2Cu3O7 à des échelles de temps compatibles avec une séquence IRM (< 1 msec) est un véritable défi, à la fois scientifique et technologique. Ce travail de recherche a pour but d'évaluer les performances de matériaux supraconducteurs à haute température critique tels que l' YBa2Cu3O7 en champ magnétique et dans le domaine des RF, en fonction de leurs propriétés nano-structurales et géométriques, et de développer un système permettant une commutation ultra rapide (ms) de l'état supraconducteur à l'état dissipatif et réciproquement, afin d'éviter le phénomène de concentration du flux magnétique lors de la phase émission, et de préserver la sensibilité du résonateur supraconducteur lors de la phase détection. / The aim of this work is to develop an instrumental device based on the nonlinear behaviour of superconducting materials such as YBa2Cu3O7 as a function of the emitted rf power, with the objective of controlling the switch between the zero resistance state and a dissipative state. This will then be applied to superconducting ultra-sensitive coils dedicated to magnetic resonance imaging (MRI). The implementation of HTS coils for biomedical imaging improves the sensitivity of the acquired images in standard clinical MRI devices. The superconducting coils are currently not implemented because of their incompatibility with quantitative detection methods used in molecular imaging today. As usual decoupling techniques for pick-up coils are not transferable to superconducting materials, the inactivation of superconducting YBa2Cu3O7 coils is a technical and a scientific challenge. The overall objective of this research work is to evaluate the performance of HTS materials in non-zero magnetic fields, in the radiofrequency regime, as a function of the nanostructural and geometric attributes of the material. Based on this, I shall develop a system for ultra-fast switch (msec) from the superconducting state to the dissipative state and vice versa, to avoid the phenomenon of of magnetic flux concentration during the emission phase.