Work described in this thesis is concerned with localisation techniques, for determining the position, of wireless sensors whilst these are immersed in confined industrial processes, such as those occurring in the chemical, pharmaceutical and food processing industries. Two different approaches to localisation were investigated. The first approach employed an existing hardware system that used ultra wide band (UWB) signals whist the second approach used a network localisation method based on information from narrow-band received signals. A prototype UWB-based localisation algorithm processed experimental received UWB pulses to detect their leading edges (LE) that were used to derive Time Difference of Arrival (TDoA) data. In turn TDoA data were converted into distances and used to compute the locations of the sensor nodes. Nevertheless, the process of detecting the LEs caused significant errors in the localisation process. To deal with this problem new automated adaptive LE detection methods were derived that succeeded in reducing localisation errors by half, compared to the prototype method, reaching accuracies of ±2cm. Thorough analysis of TDoA profiles revealed that these follow specific trends depending on the positions of the sensor nodes. A number of properties of TDoA profiles are proved mathematically and incorporated into seven localisation algorithms. These algorithms were examined using experimental TDoA data and shown to achieve average localisation errors up to 3cm. Network-based localisation was examined at a later stage of this research since complexities of large scale measurements and difficulties with equipment, delayed acquiring experimental data. The deployed network consisted of a number of nodes whose positions were known (anchors) that were used to estimate the positions of sensor nodes whose positions where considered to be unknown. Localisation was based on received signal strength (RSS) data, at every node to be localised, in anticipation that RSS could provide distance information that could be used in the localisation procedure. Nevertheless, fluctuations in RSS only allowed using localisation algorithms that associated RSS to the positions of anchors. The average localisation error in the network-based localisation algorithms was between 30cm to 100cm.

The purpose of this thesis was to assess the plausibility of using two Ultra- Wideband radars for detecting and tracking human targets. The detection has been performed by two different types of methods, constant false-alarm rate methods and a type of CLEAN algorithm. For tracking the targets, multiple hypothesis tracking has been studied. Particle filtering has been used for the state prediction, considering a significant amount of uncertainty in a motion model used in this thesis project. The detection and tracking methods have been implemented in MATLAB. Tracking in the cases of a single target and multiple targets has been investigated in simulation and experiment. The simulation results in these cases were compared with accurate ground truth data obtained using a VICON optical tracking system. The detection methods showed poor performance when using data that had been collected by the two radars and post-processed to enhance target features. For single targets, the detections were accurate enough to continuously track a target moving randomly in a controlled area. In the multiple target cases the tracker was not able to distinguish the multiple moving subjects.

abstract: Suction stabilized floats have been implemented into a variety of applications such as supporting wind turbines in off-shore wind farms and for stabilizing cargo ships. This thesis proposes an alternative use for the technology in creating a system of suction stabilized floats equipped with real time location modules to help first responders establish a localized coordinate system to assist in rescues. The floats create a stabilized platform for each anchor module due to the inverse slack tank effect established by the inner water chamber. The design of the float has also been proven to be stable in most cases of amplitudes and frequencies ranging from 0 to 100 except for when the frequency ranges from 23 to 60 Hz for almost all values of the amplitude. The modules in the system form a coordinate grid based off the anchors that can track the location of a tag module within the range of the system using ultra-wideband communications. This method of location identification allows responders to use the system in GPS denied environments. The system can be accessed through an Android app with Bluetooth communications in close ranges or through internet of things (IoT) using a module as a listener, a Raspberry Pi and an internet source. The system has proven to identify the location of the tag in moderate ranges with an approximate accuracy of the tag location being 15 cm. / Dissertation/Thesis / Masters Thesis Engineering 2020

The Global Positioning System (GPS) and other satellite-based positioning systems are often a key component in applications requiring localization. However, accurate positioning in areas with poor GPS coverage, such as inside buildings and in dense cities, is in increasing demand for many modern applications. Fortunately, recent developments in ultra-wideband (UWB) radio technology have enabled precise positioning in places where it was not previously possible by utilizing multipath-resistant wide band pulses. Although ultra-wideband signals are less prone to multipath interference, it is still a bottleneck as increasingly ambitious projects continue to demand higher precision. Some UWB radios include on-board detection of multipath conditions, however the implementations are usually limited to basic condition checks. In order to address these shortcomings, We propose an application of machine learning to reliably detect non-line-of-sight conditions when the on-board radio classifier fails to recognize these conditions. Our solution includes a neural network classifier that is 99.98% accurate in a variety of environments.

Ce mémoire présente la conception d'un radar Ultra Large Bande à déclenchement optoélectronique dédié au rayonnement d'impulsions ultra-courtes dans une bande de travail comprise entre 300MHz et 3GHz pour réaliser des opérations de détection à courte et moyenne portée. A l'émission, ce radar est composé de plusieurs sources de rayonnement élémentaires constituées d'une antenne au sein de laquelle un générateur optoélectronique est intégré, d'un générateur de haute tension pulsée et d'un système commande optique. Des mesures de validation ont été menées pour s'assurer du bon fonctionnement d'une source. Cette association garantit une excellente synchronisation entre les sources et autorise un balayage électromagnétique autonome rapide en ajustant les fréquences de répétition (quelques dizaines de MHz) de chaque générateur de manière à décaler proportionnellement à l'angle visé, l'instant d'alimentation. A la réception, une antenne ou plusieurs antennes sont utilisées pour récupérer les signaux diffractés par les cibles et un traitement de signal est appliqué pour reconstruire l'image. Ce traitement spécifique permet de s'affranchir de la limite de détection en distance imposée par la fréquence de répétition en utilisant une association entre des calculs de corrélation et une déconvolution itérative. Un des vecteurs d'amélioration de la qualité de l'image a également été développé. Il concerne la génération de forme d'ondes et plus particulièrement le façonnage spectral par profilage temporel en utilisant un algorithme d'optimisation évolutionnaire. / This thesis presents the design of an Ultra Wide Band radar triggered by an optoelectronic generator which is dedicated to ultra short pulses radiation for short and medium range detection. The emitting part of this radar is based on transmitting array composed of several UWB antennas with an integrated photoswitch device triggered using optical pulses and a receiving UWB antenna. A specific signal processing method has been proposed and implemented for UWB optoelectronic radar involving autonomous beam scanning capability in order to overcome the limitation in the depth of detection encountered while using standard imaging algorithm. Indeed, this hybrid correlation/CLEAN algorithm considers the whole measured burst and finds the relevant information to rebuilt a radar map with a very good accuracy. In order to improve the radar map quality, the waveform generation technique has been discussed and, more precisely, the temporal shaping method to obtain specific spectrum using evolutionary algorithm.

The continual increase of wireless technologies in the world has motivated the use of phased arrays to mitigate radio frequency interference (RFI). There are many methods of performing beamforming for RFI rejection, but they are traditionally physically large and complicated solutions. Phased arrays need to be shrunk and made cheaper for them to see widespread use. This work presents several compact phased array receivers for different applications. The first part of this thesis presents a software GPS processor for a digital beamforming GPS receiver. The receiver is small enough to be flown on drones and enables GPS signals to be processed and a user’s position to be determined. Using digital beamforming, it can operate even under poor conditions such as intentional jamming, RFI, and large multipath effects. Next, this work builds a frontend RF chain for a true time delay phased array receiver. The receiver uses analog true delay delay chips to mitigate radio frequency interference in sensitive instruments. True time delay allows for analog beamforming over a wide bandwidth, but compact true time delay solutions are new and untested. The receiver allows these solutions to be properly vetted in a full system. The chain uses novel compact wideband antennas for L-band frequencies and traditional low cost amplifiers and filters. The last section of this thesis updates the open-source CASPER project to fully support RF system-on-chips. CASPER is an open-source framework for radio astronomy instruments. It speeds up the design and implementation of radio astronomy instruments on compact platforms and makes them easier to interact with. This work expands the framework to use the transmit abilities of advanced RF system-on-chip platforms. With this expansion, full duplex systems such as communications and radar can now also use CASPER. A full loopback beamforming test built on CASPER demonstrates both transmit and receive beamforming.

The state-of-the-art commercially available radio-frequency identification (RFID) transponders are usually composed of an antenna and an application specific integrated circuit chip, which still makes them very costly compared to the well-established barcode technology. Therefore, a novel low-cost RFID system solution based on passive chipless RFID transponders manufactured using conductive strips on flexible substrates is proposed in this work. The chipless RFID transponders follow a specific structure design, which aim is to modify the shape of the impinged electromagnetic wave to embed anidentification code in it and then backscatter the encoded signal to the reader. This dissertation comprises a multidisciplinary research encompassing the design of low-cost chipless RFID transponders with a novel frequency coding technique, unlike usually disregarded in literature, this approach considers the communication channel effects and assigns a unique frequency response to each transponder. Hence, the identification codes are different enough, to reduce the detection error and improve their automatic recognition by the reader while working under normal conditions. The chipless RFID transponders are manufactured using different materials and state-of-the-art mass production fabrication processes, like printed electronics. Moreover, two different reader front-ends working in the ultra-wideband (UWB) frequency range are used to interrogate the chipless RFID transponders. The first one is built using high-performance off-theshelf components following the stepped frequency modulation (SFM) radar principle, and the second one is a commercially available impulse radio (IR) radar. Finally, the two readers are programmed with algorithms based on the conventional minimum distance and maximum likelihood detection techniques, considering the whole transponder radio frequency (RF) response, instead of following the commonly used approach of focusing on specific parts of the spectrum to detect dips or peaks. The programmed readers automatically identify when a chipless RFID transponder is placed within their interrogation zones and proceed to the successful recognition of its embedded identification code. Accomplishing in this way, two novel fully automatic SFM- and IRRFID readers for chipless transponders. The SFM-RFID system is capable to successfully decode up to eight different chipless RFID transponders placed sequentially at a maximum reading range of 36 cm. The IR-RFID system up to four sequentially and two simultaneously placed different chipless RFID transponders within a 50 cm range.:Acknowledgments Abstract Kurzfassung Table of Contents Index of Figures Index of Tables Index of Abbreviations Index of Symbols 1 Introduction 1.1 Motivation 1.2 Scope of Application 1.3 Objectives and Structure Fundamentals of the RFID Technology 2.1 Automatic Identification Systems Background 2.1.1 Barcode Technology 2.1.2 Optical Character Recognition 2.1.3 Biometric Procedures 2.1.4 Smart Cards 2.1.5 RFID Systems 2.2 RFID System Principle 2.2.1 RFID Features 2.3 RFID with Chipless Transponders 2.3.1 Time Domain Encoding 2.3.2 Frequency Domain Encoding 2.4 Summary Manufacturing Technologies 3.1 Organic and Printed Electronics 3.1.1 Substrates 3.1.2 Organic Inks 3.1.3 Screen Printing 3.1.4 Flexography 3.2 The Printing Process 3.3 A Fabrication Alternative with Aluminum or Copper Strips 3.4 Fabrication Technologies for Chipless RFID Transponders 3.5 Summary UWB Chipless RFID Transponder Design 4.1 Scattering Theory 4.1.1 Radar Cross-Section Definition 4.1.2 Radar Absorbing Material’s Principle 4.1.3 Dielectric Multilayers Wave Matrix Analysis 4.1.4 Frequency Selective Surfaces 4.2 Double-Dipoles UWB Chipless RFID Transponder 4.2.1 An Infinite Double-Dipole Array 4.2.2 Double-Dipoles UWB Chipless Transponder Design 4.2.3 Prototype Fabrication 4.3 UWB Chipless RFID Transponder with Concentric Circles 4.3.1 Concentric Circles UWB Chipless Transponder 4.3.2 Concentric Rings UWB Chipless RFID Transponder 4.4 Concentric Octagons UWB Chipless Transponders 4.4.1 Concentric Octagons UWB Chipless Transponder Design 1 4.4.2 Concentric Octagons UWB Chipless Transponder Design 2 4.5 Summary 5. RFID Readers for Chipless Transponders 5.1 Background 5.1.1 The Radar Range Equation 5.1.2 Range Resolution 5.1.3 Frequency Band Selection 5.2 Frequency Domain Reader Test System 5.2.1 Stepped Frequency Waveforms 5.2.2 Reader Architecture 5.2.3 Test System Results 5.3 Time Domain Reader 5.3.1 Novelda Radar 5.3.2 Test System Results 5.4 Summary Detection of UWB Chipless RFID Transponders 6.1 Background 6.2 The Communication Channel 6.2.1 AWGN Channel Modeling and Detection 6.2.2 Free-Space Path Loss Modeling and Normalization 6.3 Detection and Decoding of Chipless RFID Transponders 6.3.1 Minimum Distance Detector 6.3.2 Maximum Likelihood Detector 6.3.3 Correlator Detector 6.3.4 Test Results 6.4 Simultaneous Detection of Multiple UWB Chipless Transponders 6.5 Summary System Implementation 7.1 SFM-UWB RFID System with CR-Chipless Transponders 7.2 IR-UWB RFID System with COD1-Chipless Transponders 7.3 Summary Conclusion and Outlook References Publications Appendix A RCS Calculation Measurement Setups Appendix B Resistance and Skin Depth Calculation Appendix C List of Videos Test Videos Consortium Videos Curriculum Vitae

Millimetre-wave technology is used for applications such as telecommunications and imaging. For both applications, the bandwidth of existing systems has to be increased to support higher data rates and finer imaging resolutions. Millimetrewave circuits with very large bandwidths are developed in this thesis. The focus is put on amplifiers and the on-chip integration of the amplifiers with antennas. Circuit prototypes, fabricated in a commercially available 130nm Silicon-Germanium (SiGe) Bipolar Complementary Metal-Oxide-Semiconductor (BiCMOS) process, validated the developed techniques. Cutting-edge performances have been achieved in the field of distributed and resonant-matched amplifiers, as well as in that of the antenna-amplifier co-integration. Examples are as follows: - A novel cascode gain-cell with three transistors was conceived. By means of transconductance peaking towards high frequencies, the losses of the synthetic line can be compensated up to higher frequencies. The properties were analytically derived and explained. Experimental demonstration validated the technique by a Traveling-Wave Amplifier (TWA) able to produce 10 dB of gain over a frequency band of 170GHz.# - Two Cascaded Single-Stage Distributed Amplifiers (CSSDAs) have been demonstrated. The first CSSDA, optimized for low power consumption, requires less than 20mW to provide 10 dB of gain over a frequency band of 130 GHz. The second amplifier was designed for high-frequency operation and works up to 250 GHz leading to a record bandwidth for distributed amplifiers in SiGe technology. - The first complete CSSDA circuit analysis as function of all key parameters was presented. The typical degradation of the CSSDA output matching towards high frequencies was analytically quantified. A balanced architecture was then introduced to retain the frequency-response advantages of CSSDAs and yet ensure matching over the frequency band of interested. A circuit prototype validated experimentally the technique. - The first traveling-wave power combiner and divider capable of operation from the MHz range up to 200 GHz were demonstrated. The circuits improved the state of the art of the maximum frequency of operation and the bandwidth by a factor of five. - A resonant-matched balanced amplifier was demonstrated with a centre frequency of 185 GHz, 10 dB of gain and a 55GHz wide –3 dB-bandwidth. The power consumption of the amplifier is 16.8mW, one of the lowest for this circuit class, while the bandwidth is the broadest reported in literature for resonant-matched amplifiers in SiGe technology.

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High accuracy localization of objects is a crucial function for many modern applications, such as virtual and augmented reality, robotics, and self-driving cars, among others. This requires determining precise location of objects indoors, which is a challenging task. In recent years, Ultra-Wideband technology has seen increasing interest as a potential solution to this problem by the research community. This is mainly due to its innate capabilities of high update frequency and low power consumption which makes it a suitable technology for precise distance measurement and location determination. This study has aimed to answer what the state-of-the-art in the field of trilateration in Ultra-Wideband based indoor positioning systems utilizing other complementary technologies is. This was done by conducting a document survey using a Grounded theory approach for the analysis. To ensure validity and reliability of the study, the sample was collected through searching IEEE Xplore using different sets of keywords, and the potential samples was then checked using a data quality form. The analysis consisted of identifying categories and concepts in the sample. The analysis found that the Ultra-wideband based systems can achieve high positioning accuracy, but limitations such as non-line-of-sight disturbance must still be overcome for the technology to consistently achieve centimetre accuracy. These limitations are being mitigated using filtering, machine learning, and multi-sensory fusion. With these complementary technologies researchers can eliminate some of the limitations. The field does however seem to be in an exploratory stage where best practices for overcoming the current limitations are yet established.