Dissertations / Theses on the topic 'Switched arrays'

This thesis investigates the ability of Switched Active Switched Parasitic antenna (SASPA) as direction finding arrays. SASPA array consists of N identical antennas in which one element is in active state while the others are parasites during one point of measurement time. The improvements in direction of arrival estimation achieved by using SASPA arrays were examined under different scenarios of the data model. Several estimations were conducted to depict the outperformance of SASPA arrays over all-active antenna arrays.

Mobile arrays employing diversity combining and adaptive beamforming techniques overcome multipath fading, improve coverage, and increase capacity in wireless communications systems. In this thesis, diversity combining and adaptive beamforming performance of different four element arrays for mobile (vehicular speed) and portable (pedestrian speed) terminals is investigated. The performance of four element arrays with different configurations and with different element patterns is compared using the square array of four half-wave dipole elements as the baseline. Results from diversity and beamforming measurements, performed in urban and suburban environments for both line-of-sight (LOS) and obstructed multipath channels are used to analyze and compare the performances of different four element arrays. At cumulative probabilities of 10%, 1% and 0.1%, diversity gain and improvement in signal-to-interference-plus-noise-ratio (SINR) are calculated from the diversity combining measurements and interference rejection measurements respectively. Experimental results illustrating the dependence of diversity gain on power imbalance, envelope correlation and diversity-combining scheme are presented. Measurements were performed at 2.05 GHz using the handheld antenna array testbed (HAAT). Low profile linear arrays are shown to provide diversity gain values of 5 to 8 dB and 11 to 16 dB, respectively for switched and maximal ratio combining at the 99% reliability level in non-line-of-sight urban channel. Interference cancellation of 24 to 28 dB was recorded in urban and suburban line-of-sight (LOS) channels for the sectorized square array. Results of vehicular measurements with the arrays mounted on a ground plane supported above the vehicle roof are also reported.
Master of Science

This thesis is concerned with the use of multiple antenna elements in wireless communication over frequency non-selective radio channels. Both measurement results and theoretical analysis are presented. New transmit strategies are derived and compared to existing transmit strategies, such as beamforming and space-time block coding (STBC). It is found that the best transmission algorithm is largely dependent on the channel characteristics, such as the number of transmit and receive antennas and the existence of a line of sight component. Rayleigh fading multiple input multiple output (MIMO) channels are studied using an eigenvalue analysis and exact expressions for the bit error rates and outage capacities for beamforming and STBC is found. In general are MIMO fading channels correlated and there exists a mutual coupling between antenna elements. These findings are supported by indoor MIMO measurements. It is found that the mutual coupling can, in some scenarios, increase the outage capacity. An adaptive antenna testbed is used to obtain measurement results for the single input multiple output (SIMO) channel. The results are analyzed and design guidelines are obtained for how a beamformer implemented in hardware shall be constructed. The effects of nonlinear transmit amplifiers in array antennas are also analyzed, and it is shown that an array reduces the effective intermodulation distortion (IMD) transmitted by the array antenna by a spatial filtering of the IMD. A novel frequency allocation algorithm is proposed that reduces IMD even further. The use of a low cost antenna with switchable directional properties, the switched parasitic antenna, is studied in a MIMO context and compared to array techniques. It is found that it has comparable performance, at a fraction of the cost for an array antenna.

Ultrasound is predominantly an ‘active’ sensing modality, with information obtained by transmission of an acoustic wave, followed by analysis of received signals. Transmission occurs when electrical signals are converted to acoustic signals. This thesis covers the design and application of these electrical signals to an array transducer. As an introduction, the development of a bespoke ultrasound array research platform is discussed. This enabling technology is built around switched-mode excitation: a method of approximating an analogue waveform by selecting between discrete voltage levels. The use of switched-mode methods has led to three major topics of research. Firstly, a transmit beamformer architecture that provides fine control of excitation sequence timing using embedded-phase locked loops is presented. This enables accurate implementation of firing sequences or phasing between transducer elements, thus minimizing time-quantization error, and providing an improved representation of the expected pressure field. An introduction to transmit beamforming is given, the impact of timequantization is discussed, and the transmit beamformer’s performance is demonstrated. Secondly, a method of arbitrary waveform generation using switched-mode excitation is described. The method encodes width-modulated sequences of three or five discrete voltage levels, that, once passed through a transducer, give close approximation to the desired arbitrary waveform. Applications include: power control, pulse shaping, and array apodization. Each application is demonstrated by simulation and experimentation. An extension to the method is shown for ‘chirp’ coded imaging, demonstrating the capability for generation of frequency modulated waveforms. The improvement in image quality when compared with conventional square-wave, ‘pseudo-chirp’ excitation signals is shown. Lastly, the performance of the width-modulated signals is further extended so as to remove unwanted third-harmonic content whilst still maintaining pulse amplitude control.Removal of the third harmonic reduces harmonic distortion, has benefits in applications such as harmonic imaging, and extends the use of switched-mode operation with wide bandwidth transducers.

Most people are familiar with Radio Frequency Identification (RFID) technology as its applications are around us in many systems, such as anti-theft devices in shops, supermarkets and libraries, building access systems. The number of applications and devices has developed explosively in the past decade and has become one of the fastest growing sectors of the radio technology industry. RFID systems allow information to be attached to items such as products, animals or even people. This information may be read, and in some cases changed, by an RFID reader some distance away. RFID localisation systems are an active area of research as they add further capabilities to current RFID systems. Localisation allows the position of tagged items to be determined from the RFID communications signal. Current systems can confirm that a specific item is within the reader read range but finding the item requires a systematic search. The primary objective of this thesis is to build a new, economical and versatile 2.45 GHz localisation system for active and passive RFID tags. Alternative systems rely upon signal strength measurements and yield large uncertainties due to the unknown orientation of the tags. The proposed system reader consists of a microstrip switched beam array antenna. The array antenna allows the estimation of the angular position of the tag. The use of two or more readers provides the tags position by triangulation. The array antenna provides other advantages such as improved read range and mitigation against interference and multipath fading. In the process of designing the antenna array, several new, compact, slotted, circularly polarised, square patch antennas have been produced. A range of technologies have been applied to achieve miniaturisation of the microwave circuit elements require to drive the antenna array, the Butler matrix (BM). Fabricated circuits achieve significant size area reduction with similar performances compared to the conventional ones. These developments will have wide application beyond the RFID localisation system. Finally, accuracy of the system varies with angle due to the complicated relationships between Angle of Arrival (AoA) and port output powers. The localisation algorithm along with measured power inside the standard anechoic room show that the standard deviations of the AoA estimation errors less than 1.6° for most angles in the operational range from -90 degrees to 90 degree and a standard error less than 0.6o for AoA angles with 20o of the perpendicular at AoA with power ratios perturbed by additive noise of standard deviation 0.5 dB.

Cette thèse étudie deux aspects d'un système de contrôle d'accès de véhicule par localisation de clés.D'une part, dans le cadre d'une localisation par triangulation à l'aide de réseaux de capteurs commutés, l'optimisation de la séquence de commutation est étudiée.Un modèle est proposé pour étudier l'estimation des paramètres de sinusoïdes reçues par un réseau de capteur, dont les capteurs sont échantillonnés de manière asynchrone.Ce modèle est notamment, mais pas exclusivement, applicable à des approches industrielles telles que celle proposée par Bluetooth 5.1, qui sert d'application de référence.Du modèle sont dérivées des bornes de Cramér-Rao, qui servent à l'établissement de critères d'optimisation des instants d'échantillonnage de chaque capteur indépendants de la géométrie du réseau de capteurs.Les formes analytiques de ces critères permettent d'établir des propriétés préférables pour les instants d'échantillonnage de chaque capteur, particulièrement lorsque la fréquence des signaux reçus n'est pas connue à priori.Des stratégies sont proposées pour générer des séquences de commutation, et sont évaluées numériquement à l'aide des critères proposés. L'évolution des critères proposés est comparée à celle de bornes numériques sur l'estimation d'angle d'incidence pour des géométries populaires, illustrant un lien qualitatif entre ces critères.D'autre part, dans le cadre d'une localisation par mesure des délais de propagation en bande UWB, un système de détection de passagers reposant sur le matériel de localisation est proposé.On propose d'utiliser des machines à vecteurs-supports (SVM) pour réaliser la détection des passagers sous la forme d'une classification des réponses impulsionnelles de canal mesurées entre les transmetteurs du système de localisation de clé.Une preuve de concept et un prototype sont réalisés et utilisés pour collecter des données sur le problème et montrer la faisabilité.L'étude de ces données permet d'identifier des invariances, que l'on propose de traduire pour les SVM à travers des traitements et métriques adaptés.Les performances offertes par ces traitements sont ensuite mesurées expérimentalement, et permettent d'affirmer qu'un des traitements proposés est avantageux pour l'application choisie
This thesis studies two aspects of a vehicle access control system which relies on the estimation of a key's location to grant access.Firstly, within the context of a triangulation-based system, we study the optimisation of the switching sequence for switched antenna-arrays.A model is given to study the estimation of the parameters of sines received by a switched array, where sensors are not necessarily sampled synchronously.This model is relevant, but not exclusive, to industrial approaches to direction of arrival estimation, such as the one proposed by Bluetooth 5.1, which serves as our reference application.From the model, Cramér-Rao lower bounds are computed, and are used to define design criteria for switching sequences that do not rely on the array's geometry.These criteria's analytical forms allow us to highlight desirable properties in switching sequences, especially in the case where the signal's frequency is unknown.Strategies to build switching sequences are proposed, and numerically evaluated using the provided criteria. Comparison of the criteria with numerical bounds on direction of arrival for common array geometries shows that they are qualitatively linked.Secondly, within the context of a time of flight based system, we propose a system for passenger detection that relies solely on the localization system's original hardware.To achieve this, we propose to use support vector machines (SVM) to classify the channel impulse responses measured between the system's transmitters.A proof of concept is designed to demonstrate feasability, and data is collected on a prototype for further evaluation.By studying the available data, invariants are identified, and processing functions are proposed to translate these invariants to the SVM in order to improve performance.One of the proposed processing is shown to give performance gains for our application through experiments

This project presents a novel copper DC-contact RF-MEMS cantilever switch to operate with microstrip phased array antennas for the main frequency of operation of 12.5GHz. Effective performance, low cost, compact size, and full integration are the main requirements that phased array antennas and RF-MEMS technologies should meet to make an impact on the market. Then, a cost-effective all-monolithically integrated architecture of phased array antenna with RF-MEMS switches on a commercial printed circuit board (PCB) laminate has been developed as a solution. A new manufacturing technique using photolithography processes has been developed for RF-MEMS cantilever switches based on thin copper films (1um-2um) on a PCB to address the cost and full integration requirements. This technique has allowed fabrication of various switches, of which the mechanical and electromagnetic performance have been measured and found to be suitable for operation with phased arrays. The accomplishment of an all-monolithically integrated architecture has been demonstrated by means of simulations, having been able to electronically steer the main beam to different positions with acceptable radiation characteristics at 12.5GHz. Therefore, in this work it has been possible to demonstrate that good performance and cost-effective phased array antennas are potentially viable by monolithically integrating reliable RF-MEMS on commercial PCBs. Having reliable RF-MEMS built on PCB, there is potential to extend the areas of applications of this type of RF-MEMS, not only for phased array antennas but also for other attractive commercial applications. The research carried out in this project, moreover, represents an important contribution for further development of satisfactory RF-MEMS at very low cost for high frequency systems.

This thesis presents an introduction to the design and simulation of a novel class of integrated photonic phased array switch elements. The main objective is to use nano-electromechanical (NEMS) based phase shifters of cascaded under-etched slot nanowires that are compact in size and require a small amount of power to operate them. The structure of the switch elements is organized such that it brings the phase shifting elements to the exterior sides of the photonic circuits. The transition slot couplers, used to interconnect the phase shifters, are designed to enable biasing one of the silicon beams of each phase shifter from an electrode located at the side of the phase shifter. The other silicon beam of each phase shifter is biased through the rest of the silicon structure of the switch element, which is taken as a ground. Phased array switch elements ranging from 2×2 up to 8×8 multiple-inputs/multiple-outputs (MIMO) are conveniently designed within reasonable footprints native to the current fabrication technologies. Chapter one presents the general layout of the various designs of the switch elements and demonstrates their novel features. This demonstration will show how waveguide disturbances in the interconnecting network from conventional switch elements can be avoided by adopting an innovative design. Some possible applications for the designed switch elements of different sizes and topologies are indicated throughout the chapter. Chapter two presents the design of the multimode interference (MMI) couplers used in the switch elements as splitters, combiners and waveguide crossovers. Simulation data and design methodologies for the multimode couplers of interest are detailed in this chapter. Chapter three presents the design and analysis of the NEMS-operated phase shifters. Both simulations and numerical analysis are utilized in the design of a 0º-180º capable NEMS-operated phase shifter. Additionally, the response of some of the designed photonic phased array switch elements is demonstrated in this chapter. An executive summary and conclusions sections are also included in the thesis.

Floating-gate transistors similar to those used in FLASH and EEPROM can be used to build reconfigurable analog arrays. The charge on the floating gate can be modified to pass or block a signal in a cross-bar switch matrix, or it can be finely tuned to eliminate a threshold difference across a chip or set a bias. By using such a compact and versatile reconfigurable analog memory element, the number of analog circuit components included on an integrated circuit that is field-programmable is significantly higher. As a result, large-scale FPAAs can be built with the same impact on analog design that FPGAs have had on digital design. In my research, I investigate the areas floating-gate transistors can be used to impact FPAA design and implementation. An FPAA can be broken up into two basic components, elements of connection and elements of computation. With respect to connection, I show that a floating-gate switch can be used in a cross-bar matrix in place of a transmission gate resulting in less parasitic capacitance and a more linear resistance for the same size transistor. I illuminate the programming issues relating to injecting a floating-gate for use as a switch, including the drain selection circuitry and rogue injection due to gate induced drain leakage. With respect to computation, I explain how a Multiple-Input Translinear Element, or MITE, can be augmented to fit in an FPAA framework. I also discuss two different MITE implementations compatible with CMOS technology, a subthreshold MOS design and a BJT MITE that uses a lateral BJT. Beyond FPAA components, I present two alternative FPAA systems. The first is a general purpose reconfigurable analog system that uses standard analog design components that have been augmented with floating-gates. The second FPAA is built upon MITE circuits, and is focused on supporting direct system synthesis. I conclude with a discussion of a future large-scale MITE FPAA.

Thesis (Ph.D.)--University of Missouri-Columbia, 2006.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (April 26, 2007) Vita. Includes bibliographical references.

Recently, reconfigurable antennas have attracted significant interest due to their high adaptation with changing system requirements and environmental conditions. Reconfigurable antennas have the ability to change their radiation pattern, frequency or polarization independently according to the application requirements. In this thesis, three different reconfigurable antenna structures have been designed
beam-steerable meanderline antenna, dual circularly polarized meanderline antenna and dual-frequency slot-dipole array. Traveling wave meanderline antenna arrays are investigated in detail and a beam-steerable traveling wave meanderline antenna array has been introduced for X-band applications. Beam-steering capability of the antenna array has been achieved by loading the antenna elements with varactor diodes. Theoretical analysis and computer simulations of the proposed antenna have been verified with experimental results. Radiation direction of the 8-element meanderline array can be rotated 10°
by changing the varactor diode&rsquo
s bias voltage from 0V up to 20V. Also, a polarization-agile meanderline antenna array has been designed and simulated. Polarization of the circularly polarized meanderline array can be altered between right hand circularly polarized and left hand circularly polarized by using RF MEMS switches. The third type of reconfigurable antenna investigated in this thesis is a dual frequency slot-dipole array operating at X- and Ka-band. Electrical length of the slot dipoles has been tuned by using RF MEMS switches. Antenna prototypes have been manufactured for &lsquo
on&rsquo
and &lsquo
off&rsquo
states of RF MEMS switches and it has been shown that the operating frequency can be changed between 10 GHz and 15.4 GHz.

This thesis presents a novel monolithic phased array implemented using the RF MEMS technology. The structure, which is designed at 15 GHz, consists of four linearly placed microstrip patch antennas, 3-bit distributed RF MEMS low-loss phase shifters, and a corporate feed network. The RF MEMS phase shifter employed in the system consists of three sections with a total of 28 unit cells, and it occupies an area of 22.4 mm &
#61620
2.1 mm. The performance of the phase shifters is improved using high-Q metal-air-metal capacitors in addition to MEMS switches as loading elements on a high-impedance coplanar waveguide transmission line. The phased array is fabricated monolithically using an in-house surface micromachining process, where a 1.2-&
#61549
m thick gold structural layer is placed on a 500-µ
m thick glass substrate with a capacitive gap of 2 &
#61549
m. The fabrication process is simple, requires only 6 masks, and allows the implementation of various RF MEMS components on the same substrate, such as RF MEMS switches and phase shifters. The fabricated monolithic phased array occupies an area of only 6 cm &
#61620
5 cm. The measurement results show that the phase shifter can provide nearly 20&
#61616
/50&
#61616
/95&
#61616
phase shifts and their eight combinations at the expense of 1.5 dB average insertion loss at 15 GHz. The phase shifters can be actuated with 16 V, while dissipating negligible power due to its capacitive operation. It is also shown by measurements that the main beam can be steered to 4&
#61616
and 14&
#61616
by suitable settings of the RF MEMS phase shifters.

The goal of the research reported in this thesis is to establish the feasibility of a novel optical architecture for an optical route & select circuit switch suitable for implementation as a photonic integrated circuit. The proposed architecture combines Optical Phased Array (OPA) switch elements implemented as multimode interference coupler based Generalised Mach-Zehnder Interferometers (GMZI) with a planar Lüneburg lens-based optical transpose interconnection network implemented using graded metamaterial waveguide slabs. The proposed switch is transparent to signal format and, in principle, can have zero excess insertion loss and scale to large port counts. These switches will enable the low-energy consumption high capacity communications network infrastructure needed to provide environmentally-friendly broadband access to all. The thesis first explains the importance of switch structures in optical communications networks and the difficulties of scaling to a large number of switch ports. The thesis then introduces the Talbot effect, i.e. the self-imaging of periodic field distributions in free space. It elaborates on a new approach to finding the phase relations between pairs of Talbot image planes at carefully selected positions. The free space Talbot effect is mapped to the waveguide Talbot effect which is fundamental to the operation of multimode interference couplers (MMI). Knowledge of the phase relation between the MMI ports is necessary to achieve correct operation of the GMZI OPA switch elements. An outline of the design procedures is given that can be applied to optimise the performance of MMI couplers and, as a consequence, the GMZI OPA switch elements. The Lüneburg Optical Transpose Interconnection System (LOTIS) is introduced as a potential solution to the problem of excessive insertion loss and cross-talk caused by the large number of crossovers in a switch fabric. Finally, the thesis explains how a Lüneburg lens may be implemented in a graded ‘metamaterial’, i.e. a composite material consisting of ‘atoms’ arranged on a regular lattice suspended in a host by nano-structuring of silicon waveguide slabs using a single etch-step. Furthermore, the propagation of light in graded almost-periodic structures is discussed. Detailed consideration is given to the calibration of the local homogenised effective index; in terms of the local parameters of the metamaterial microstructure in the plane and the corrections necessary to accommodate slab waveguide confinement in the normal to the plane. The concept and designs were verified by FDTD simulation. A 4×4 LOTIS structure showed correct routing of light with a low insertion loss of -0.25 dB and crosstalk of -24.12 dB. An -0.45 dB excess loss for 2D analysis and an -0.83 dB insertion excess loss for 3D analysis of two side by side metamaterial Lüneburg lenses with diameter of 15 μm was measured, which suggests that the metamaterial implementation produces minimal additional impairments to the switch.

The diploma thesis is focused on the features description of electronics switches for digital switching arrays and on the design of program for optimal calculation of switching points and the figure of switches in digital switching arrays investigation. The electronics switches types, used for time circuit separation, are described in the preamble. These switches are the base of digital switching arrays and in principal two types are defined: the switch S and switch T. The switch S allows the interconnection only of the same channel intervals from incoming circuit with random outgoing circuit. The switch S is being used in multistage switching arrays in combination with the switches T because it can not be used separately. The switch T allows exchanging the time position of incoming circuit to different time position of outgoing circuit depending on connection needs. The time switch can substitute the space switch under specific work conditions. In practice, the time switch with controlled reading and writing is used. The following part of diploma thesis is focused on the designs and calculations of optimal switching points of digital switching array which is the executive unit of switching systems. These systems directly interconnect the signals from digital multiplexes and make the basic assumptions for telecommunication networks integration. The digital switching array means the equipment which is able to connect the channels of digital multiplexes carrying the information in encoding form. The multiplexes are the most often with pulse coded modulation or adaptive delta modulation. The digital switching arrays are divided into the time and space one. The switching arrays of digital switching systems can be made by time switching array T whose realization is limited to specific capacity or by the connection of multistage arrays. Single stages sequenced one behind each other are made by the switches T and S. The space array S does not allow making the digital switching array of switching centre. The program which determines possible proposals of switching arrays from defined figure of inputs and calculates the optimal figure of switching points and switches is a part of diploma thesis.

Actuellement, nous atteignons les limites de la quatrième génération de télécommunications mobiles (4G), notamment en termes de débit disponible et de nombre d’utilisateurs maximal. Une nouvelle génération (5G) est en cours de développement pour répondre à ces besoins. Elle adressera différent cas d’usages : l’internet des objets, les communications à ultra-haut débit ainsi que des applications plus critiques telles que les véhicules autonomes ou la chirurgie à distance. Les exigences étant bien supérieures aux capacités actuelles du réseau, des solutions de rupture ont été proposées.Dans ce travail, nous avons proposé une nouvelle méthode de dimensionnement des systèmes 5G adressant les communications à très haut débit en bande Ka. Différentes architectures permettant de répondre aux spécifications définies ont été étudiées. Nous avons ensuite mis au point une méthode pour comparer leurs performances par rapport à leur consommation énergétique afin de choisir le système le plus adapté. Enfin, nous avons choisi et caractérisé une technologie CMOS avancée afin de réaliser certaines parties de ces systèmes. Nous avons conçu des commutateurs RF et des amplificateurs faible bruit intégrés, adressant les fréquences millimétriques
The limitations of the current mobile telecommunication generation (4G) are actually reached. Indeed, the available data rate and the maximum number of users are no longer sufficient. A new generation (5G) is being developed to cope with these needs. It will target different use cases: internet of things, ultra-high data rate communications, and some critical applications such as autonomous vehicles or remote surgery. The needs are much higher than the existing network capabilities. So, innovative solutions have been proposed.In this thesis work, a new sizing methodology has been developed for 5G systems. It is applied to the Ka-band high data rate communication use case. Several architectures which meet the defined specifications have been studied. A methodology has been implemented to compare their performances depending to their power consumption. Thus, the best suitable architecture for the targeted use case is chosen. Finally, an advanced CMOS technology has been chosen and characterized in order to realize parts of the 5G system. RF switches and low noise amplifier operating in the Ka-band have been designed

Optical communications systems operate at the limits of their margins to respond to increasing capacity demands. Some of the signal processing functions required must soon operate at speeds beyond electronic implementation. Optical signal processors are fundamentally analog which requires precise control of the operating state. Programmable optical components are consequently essential. The thesis explores and elucidates the properties of meshes of generalized Mach-Zehnder interferometers (GMZIs) amenable to silicon (Si) photonics integration that are based on multimode interference couplers with programmability achieved via voltage controlled phase-shift elements within the interferometer arms to perform a variety of finite impulse response (FIR) and infinite impulse response (IIR) signal processing functions. The thesis presents a novel class of integrated photonic phased array systems with a single-stage, multistage, and feedback architectures. The designed photonic integrated systems utilize nano-electromechanical-system (NEMS) operated phase shifters of cascaded free suspended slot waveguides that are compact and require a small amount of power to operate. The structure of the integrated photonic phased array switch (IPPAS) elements is organized such that it brings the NEMS-operated phase shifters to the exterior sides of the construction; facilitating electrical connection. The transition slot couplers used to interconnect the phase shifters to the rest of the silicon structure are designed to enable biasing one of the silicon beams of each phase shifter from an electrode located at the side of the phase shifter. The other silicon beam of each phase shifter is biased through the rest of the silicon structure of the fabric, which is taken as a ground. Phased array processors of 2×2 and 4×4 multiple-input-multiple-output (MIMO) ports are conveniently designed within reasonable footprints native to the current fabrication technologies. The response of the single-stage 4×4 broadband IPPAS element is determined, and its phase synthesis states required for single-throw, double-throw and broadcast routing operations are predicted. The transmission responses of the single-stage wavelength division multiplexing (WDM) processors of 2×2 and 4×4 MIMO ports are simulated. The wavelength steering capability of the transmission interferograms by applying progressive phase shifts through the array of NEMS-operated phase shift elements of the single-stage 4×4 WDM (de)multiplexer is demonstrated. The advantages of cascading broadband and WDM phased array sections are articulated through several study cases. Five different cascaded phased array architectures are trialed for the construction of non-blocking 4×4 IPPAS broadband switches that are essential elements in the construction of universal photonic processors. A cascaded 2×2 WDM (de)multiplexer that can set the bandwidth of the (de)multiplexed cyclic channels into a binary number of programmable values is demonstrated. The envelope and wavelength modulations of the transmission responses utilizing a cascaded forward structure of three 2×2 sections that can be utilized for the (de)multiplexing of different bandwidth channels are demonstrated providing individual wavelength steering capability of the narrowband and wideband channels and the individual wavelength steering capability of the slow envelope and wavelength modulating functions. Innovative universal 2×2 and 4×4 cascaded phased array processors of advanced high-order architectures that can function as both non-blocking broadband routers and tunable WDM (de)multiplexers with spectrum steering and bandwidth control of the (de)multiplexed demands are introduced. The multimode interference (MMI) coupler is utilized for the construction of several IIR feedback photonic processors. Tunable photonic feedback processors have the advantage of using less number of MMI couplers compared to their counterparts of FIR forward-path processors saving on the footprint and loss merits. A passive feedback 2×2 (de)multiplexer made of a 4×4 MMI coupler and two loopback paths is proposed. The inclusion of an imbalance in the lengths of the loopback paths of the same symmetrical feedback (de)multiplexer is demonstrated to achieve wavelength modulation of the (de)multiplexed transmission responses that are useful for the (de)multiplexing of different bandwidth channels. Several newly introduced IIR feedback architectures are demonstrated to function similarly as their counterparts of FIR forward-path processors as binary bandwidth variable (de)multiplexers, envelope and wavelength modulation (de)multiplexers, and universal feedback processors. The investigation provided in this thesis is also supported with dynamic zero-pole evolution analysis in the complex plane of analysis of the studied FIR and IIR photonic processors to enhance understanding the principle of operation. This research expands the prospective for constructing innovative silicon-on-insulator (SOI) based optical processors for applications in modern optical communication systems and programmable elastic optical networks (EONs).

The objectives of this work were to investigate, design and implement beam steering antenna arrays for mobile and wireless applications using the genetic algorithm (GA) and particle swarm optimisation (PSO) techniques as optimisation design tools. Several antenna designs were implemented and tested: initially, a printed dipole antenna integrated with a duplex RF switch used for mobile base station antenna beam steering was investigated. A coplanar waveguide (CPW) to coplanar strip (CPS) transition was adopted to feed the printed dipole. A novel RF switch circuit, used to control the RF signal fed to the dipole antenna and placed directly before it, was proposed. The measured performance of the RF switch was tested and the results confirmed its viability. Then two hybrid coupled PIN diode phase shifters, using Branchline and Rat-Race ring coupler structures, were designed and tested. The generation of four distinct phase shifts was implemented and studied. The variations of the scattering parameters were found to be realistic, with an acceptable ±2 phase shift tolerance. Next, antenna beam steering was achieved by implementing RF switches with ON or OFF mode functions to excite the radiating elements of the antenna array. The switching control process was implemented using a genetic algorithm (GA) method, subject to scalar and binary genes. Anti-phase feeding of radiating elements was also investigated. A ring antenna array with reflectors was modelled and analysed. An antenna of this type for mobile base stations was designed and simulation results are presented. Following this, a novel concept for simple beam steering using a uniform antenna array operated at 2.4 GHz was designed using GA. The antenna is fed by a single RF input source and the steering elements are reactively tuned by varactor diodes in series with small inductors. The beam-control procedure was derived through the use of a genetic algorithm based on adjusting the required reactance values to obtain the optimum solution as indicated by the cost function. The GA was also initially used as an optimisation tool to derive the antenna design from its specification. Finally, reactive loading and time modulated switching techniques are applied to steer the beam of a circular uniformly spaced antenna array having a source element at its centre. Genetic algorithm (GA) and particle swarm optimisation (PSO) processes calculate the optimal values of reactances loading the parasitic elements, for which the gain can be optimised in a desired direction. For time modulated switching, GA and PSO also determine the optimal on and off times of the parasitic elements for which the difference in currents induced optimises the gain and steering of the beam in a desired direction. These methods were demonstrated by investigating a vertically polarised antenna configuration. A prototype antenna was constructed and experimental results compared with the simulations. Results showed that near optimal solutions for gain optimisation, sidelobe level reduction and beam steering are achievable by utilising these methods. In addition, a simple switching process is employed to steer the beam of a horizontally polarised circular antenna array. A time modulated switching process is applied through Genetic Algorithm optimisation. Several model examples illustrate the radiation beams and the switching time process of each element in the array.

The objectives of this work were to investigate, design and implement beam steering antenna arrays for mobile and wireless applications using the genetic algorithm (GA) and particle swarm optimisation (PSO) techniques as optimisation design tools. Several antenna designs were implemented and tested: initially, a printed dipole antenna integrated with a duplex RF switch used for mobile base station antenna beam steering was investigated. A coplanar waveguide (CPW) to coplanar strip (CPS) transition was adopted to feed the printed dipole. A novel RF switch circuit, used to control the RF signal fed to the dipole antenna and placed directly before it, was proposed. The measured performance of the RF switch was tested and the results confirmed its viability. Then two hybrid coupled PIN diode phase shifters, using Branchline and Rat-Race ring coupler structures, were designed and tested. The generation of four distinct phase shifts was implemented and studied. The variations of the scattering parameters were found to be realistic, with an acceptable ±2 phase shift tolerance. Next, antenna beam steering was achieved by implementing RF switches with ON or OFF mode functions to excite the radiating elements of the antenna array. The switching control process was implemented using a genetic algorithm (GA) method, subject to scalar and binary genes. Anti-phase feeding of radiating elements was also investigated. A ring antenna array with reflectors was modelled and analysed. An antenna of this type for mobile base stations was designed and simulation results are presented. Following this, a novel concept for simple beam steering using a uniform antenna array operated at 2.4 GHz was designed using GA. The antenna is fed by a single RF input source and the steering elements are reactively tuned by varactor diodes in series with small inductors. The beam-control procedure was derived through the use of a genetic algorithm based on adjusting the required reactance values to obtain the optimum solution as indicated by the cost function. The GA was also initially used as an optimisation tool to derive the antenna design from its specification. Finally, reactive loading and time modulated switching techniques are applied to steer the beam of a circular uniformly spaced antenna array having a source element at its centre. Genetic algorithm (GA) and particle swarm optimisation (PSO) processes calculate the optimal values of reactances loading the parasitic elements, for which the gain can be optimised in a desired direction. For time modulated switching, GA and PSO also determine the optimal on and off times of the parasitic elements for which the difference in currents induced optimises the gain and steering of the beam in a desired direction. These methods were demonstrated by investigating a vertically polarised antenna configuration. A prototype antenna was constructed and experimental results compared with the simulations. Results showed that near optimal solutions for gain optimisation, sidelobe level reduction and beam steering are achievable by utilising these methods. In addition, a simple switching process is employed to steer the beam of a horizontally polarised circular antenna array. A time modulated switching process is applied through Genetic Algorithm optimisation. Several model examples illustrate the radiation beams and the switching time process of each element in the array.

La récupération d'énergie ambiante permet d’alimenter de manière autonome des systèmes de petite taille tels que des neouds de capteurs ou des objets connectés à internet (IoT) en remplacement des batteries. Les sources d’énergie ambiante sont par exemple, l’énergie solaire, le gradient thermique, les forces mécaniques, le rayonnement électromagnétique et la pile microbienne. Les matériaux piézoélectriques permettent de valoriser électriquement l’énergie mécanique de vibration en la convertissant directement en énergie électrique. Les niveaux de puissance assez faible (de quelques μW au mW) ont amené à développer des interfaces électriques de récupération afin d’extraire le maximum d'énergie en améliorant le couplage électromécanique. Dans ce travail, nous nous intéressons à l’amélioration de dispositif de récupération d’énergie. Deux aspects sont abordés : dans un premier temps l’étude d’un commutateur hybride synchrone électrique-mécanique est faite pour remplacer le transistor MOSFET couramment utilisé, afin de réduire sa consommation d’énergie ; dans un deuxième temps, un travail est mené sur une nouvelle structure mécanique à base de poutres reliées entre elle par des forces de répulsion magnétique. La structure obtenue par cet ensemble de poutres et de type non-linéaire à plusieurs degrés de liberté (MDOF) ce qui permet augmenter la bande passante
The future trend of Internet of Things (IoT) is bringing energy harvesting in to the core technique due to its requirement of self-power supplying. For best customer interface and eco-friendly issues, additional sensing systems are to be designed small, wireless and self-powering. Energy harvesting provides a way to realize the wireless self-powered system, it enables the device itself to obtain its own energy from their environment. Solar energy, thermal gradient, mechanical forces, are some commonly seen methods to obtain energy from the environment. The piezoelectric energy harvester is chosen to harvest vibrational energy in this study. In this work, a simple model of the original electrical smart switch driven under ultra-low power is proposed. By using the miniature device to drive the smart switch, the efficiency when low power is provided was examined. To construct an energy harvesting system in a more complete aspect, two newly proposed methods are as below: First, the hybrid-electrical-mechanical switches were utilized to replace the commonly seen electrical smart switches, to reduce its energy consumption such as threshold loss. Secondly, we designed a new mechanical structure for the cantilever array by connecting the beams using magnetic repelling force. In this way, the beams within the array were connected physically, forming a nonlinear multi-degree of freedom (MDOF) -like result

Ce travail de thèse, réalisé au Lab−STICC, dans le cadre du projet ANR MUFRED, porte sur l’étude, la conception et le développement de dispositifs hyperfréquences reconfigurables à base de dioxyde de vanadium (matériau à transition isolant-métal). Ce projet, multidisciplinaire – allant du dépôt et l’étude du matériau à la conception et la caractérisation de dispositifs RF en passant par une commande optique – vise à démontrer les performances du VO2 en tant qu’élément d’accord pour une commutation rapide (une dizaine de nanosecondes) à ultra-rapide (une centaine de picosecondes, selon la littérature). Pour ce faire, ce travail débute par une caractérisation du dioxyde de vanadium en tant qu’élément de commutation avant de l’intégrer dans des dispositifs reconfigurables.Ainsi, les premiers commutateurs SPST, SP2T et SP4T à base de VO2 sont conçus pour un contrôle de la transition isolant-métal par commande électrique et optique. Ces commutateurs sont par la suite utilisés dans la conception de déphaseurs reconfigurables 1-bit (déphasage relatif de 0° et − 45°) et 2-bits (déphasage relatif de 0°, − 90°, − 180°, − 270°) de type « True Time Delay » à lignes commutées.La suite du travail porte sur le démonstrateur ciblé par le projet MUFRED, i.e. un réseau d’antennes phasé reconfigurable à base de commutateurs de VO2. Les performances de chacun des blocs RF intervenant dans sa conception sont décrites, présentées et analysées.Les premiers démonstrateurs réalisés ont permis d’envisager des perspectives d’amélioration à court et long terme
This thesis, conducted at Lab−STICC as part of the ANR MUFRED project, focuses on the study, the design and the development of reconfigurable microwave devices based on vanadium dioxide (a metal-insulator transition material). This multidisciplinary project – from material deposition and study to the design and characterization of RF devices by way of optical control – aims to demonstrate the VO2 performances as a tuning element for fast (about ten nanoseconds) to ultra-fast (about hundred picoseconds) switching.With this aim in mind, this work begins with a characterization of vanadium dioxide as a tuning element before integrating it into reconfigurable RF devices.Thus, the first VO2 based switches, SPST, SP2T and SP4T are designed for control of the metal-insulator transition with an electrical or optical command. These switches are subsequently used in the design of reconfigurable 1-bit (relative phase shift of 0° and − 45°) and 2-bits (relative phase shift of 0°, − 90°, − 180° and − 270°) switched lines True Time Delay phase shifters.Then this study focuses on the proof-of-concept targeted by the MUFRED project, i.e. a reconfigurable phased array antennas based on VO2 switches. The performances of each RF blocks involved in its design are described, presented and analyzed.The first demonstrators carried out make it possible to foresee prospects for improvement in the short and long term

Millimeter-wave systems introduce a set of particular severe requirements from the antenna point of view in order to achieve specific performances. In this sense, high directive antennas are required to overcome the huge extra path loss. Moreover, each particular application introduces additional requirements. For example, in very high throughput (VHT) wireless personal area networks (WPANs) communication systems at 60 GHz band beam-steering antennas are needed to deal with high user random mobility and human-body shadowing characteristic of indoor environments. Similarly, beam-steering capabilities are also needed in automotive radar applications at 79 GHz, since the determination of the exact position of an object is essential for most of the functions realized by the radar sensor. In the same way, beam-scanning, which is still commonly mechanically performed nowadays, is also needed in passive imaging systems at 94 GHz. Finally, from the integration perspective, the antennas must be small, low-profile, light weight and low-cost, in order to be successfully integrated in a commercial millimeter-wave wireless system. For these reasons, many types of antenna structures have been considered to achieve high directivity and beam-steering capabilities for the aforementioned millimeter-wave communication, radar and imaging applications at 60, 79 and 94 GHz. The most part of the currently adopted solutions are based on the expensive, complex and bulky phased-array antena concept. Actually, phased-array antenna systems can scan the beam at a fast rate. However, they require a complex integration of many expensive, lossy and bulky circuits, such as solid-state phase shifters and beam-forming networks. This doctoral thesis has contributed to the study, development, and assessment of the performance of innovative antena solutions in order to improve the existing architectures at millimeter-wave frequencies, conveniently solving the problems related specifically to short-range high data rate communication systems at 60 GHz WPAN band (including future 5G millimeter-wave systems), automotive radar sensors at 79 GHz band, and communications, radar, and imaging systems at 94 GHz. The specific goals pursued in this work, focused on defining an alternative antenna architecture able to achieve a full reconfigurable 2-D beam-scanning of high gain radiation beams at millimeter-wave frequencies, has been fulfilled. In this sense, this thesis has been mainly devoted to study in depth and practically develop the fundamental part of an innovative switched-beam antenna array concept: novel inhomogeneous gradient-index dielectric flat lenses, which, despite their planar antenna profile configurations, allow full 2-D beam-scanning of high gain radiation beams. A transversal study, going from theoretical investigations, passing by numerical analysis, new fabrication strategies, performance evaluation, and to full experimental assessment of the new antenna architectures in real application environment has been successfully carried out.
Los sistemas a frecuencias de ondas milimétricas introducen una serie de requisitos muy estrictos desde el punto de vista de la antena con el objetivo de conseguir unos rendimientos específicos. En este sentido, se requieren antenas con una muy alta directividad con tal de conseguir superar las enormes pérdidas adicionales por propagación. Además, cada aplicación en concreto introduce unos requisitos adicionales. Por ejemplo, en redes de área personal de alta velocidad para sistemas de comunicación a la banda de 60 GHz, antenas con la capacidad de reconfiguración del haz de radiación son necesarias para poder tratar la problemática de la alta movilidad de los usuarios en entornos cerrados. De la misma forma, capacidades de reconfiguración de la orientación del haz de radiación son necesarias en aplicaciones relacionadas con radar de automoción a 79 GHz, dado que la determinación de la posición exacta de un objeto es esencial para muchas de las funciones del sensor de radar. De forma muy similar, la capacidad de apuntamiento del haz, que muchas veces todavía se realiza mediante sistemas mecánicos, es también imprescindible en sistemas de escaneo para aplicaciones biomédicas y de seguridad a 94 GHz. Finalmente, desde la perspectiva de la integración, las antenas deben ser eléctricamente pequeñas, ligeras, y económicas para poder ser incorporadas a un sistema inalámbrico comercial a frecuencias de onda milimétricas. Por todos estos motivos, diferentes tipos de estructuras de antenas han sido propuestos para conseguir alta directividad, junto con capacidades de reconfiguración y apuntamiento del haz de radiación para las aplicaciones anteriormente mencionadas y descritas en la banda de 60, 79, y 94 GHz. La solución tradicionalmente adoptada en este tipo de casos està estrictamente basada en el siempre caro, complejo y aparatoso concepto del phased-array. De hecho, los phased-arrays permiten el rápido escaneo de haces de radiación de alta directividad. Sin embargo, el hecho que requieran una compleja integración de muchos y caros componentes a alta frecuencia, tales como desfasadores de estado sólido o redes de conformación, los cuales introducen ciertos niveles de pérdidas, siendo además aparatosos, hacen que esta solución resulte inviable. La presente tesis doctoral contribuye al estudio, desarrollo, y ensayo experimental del rendimiento de soluciones de antenas innovadoras para la mejora de las existentes arquitecturas de antena en la banda frecuencial de las ondas milimétricas, convenientemente solucionando los problemas asociados específicamente a los sistemas de comunicación de corto alcance y alta velocidad a 60 GHz (incluyendo los futuros sistemas 5G a milimétricas), a los sistemas de radar de automoción a 79 GHz, y a los sistemas de comunicación, radar, y escaneo para aplicaciones a 94 GHz. Los objetivos específicos perseguidos en este trabajo académico, focalizados en definir una arquitectura alternativa de antena, capaz de conseguir una completa reconfiguración y escaneo de los haces de radiación en dos dimensiones del espacio a frecuencias de onda milimétricas, se han conseguido plenamente. En este sentido, esta tesis doctoral ha sido dedicada esencialmente al estudio en profundidad y desarrollo práctico de la parte fundamental del innovador concepto del switchedbeam array: nuevas lentes dieléctricas inhomogéneas de gradiente de índice con estructura plana, las cuales, a pesar de su configuración física totalmente llana, permiten una reconfiguración total, en dos dimensiones del espacio, de haces de radiación de alta directividad. Un estudio eminentemente transversal, que abarca desde la investigación teórica, pasando por el análisis numérico, nuevas metodologías y técnicas de fabricación, evaluación de rendimientos, hasta una completa caracterización y ensayo del rendimiento en entornos reales de aplicación de las nuevas arquitecturas de antena, se ha llevado a cabo con total éxito.
Els sistemes a freqüències d'ones mil·limètriques introdueixen una sèrie de requisits molt estrictes des del punt de vista de l'antena per tal d’aconseguir uns rendiments específics. En aquest sentit, es requereixen antenes amb una alta directivitat per aconseguir superar les enormes pèrdues addicionals per propagació. A més a més, cada aplicació en concret introdueix uns requeriments addicionals . Per exemple, en xarxes d'àrea personal d'alta velocitat per a sistemes de comunicació a la banda de 60 GHz, antenes amb la capacitat de reconfiguració del feix de radiació són necessàries per tal de poder tractar la problemàtica de l'alta mobilitat dels usuaris en entorns tancats . De la mateixa manera, capacitats de reconfiguració de l'orientació del feix de radiació són necessàries en aplicacions associades a radar d'automoció a 79 GHz, donat que la determinació de la posició exacta d'un objecte és essencial per moltes de les funcions portades a terme pels ens or del radar. De forma molt similar, la capacitat d'apuntament del feix, que moltes vegades encara es realitza per mitjà de sistemes mecànics, és també imprescindible en sistemes d'escaneig per aplicacions mèdiques i de seguretat a 94 GHz. Finalment, des de la perspectiva de la integració, les antenes han de ser petites en termes elèctrics, lleugeres, i econòmiques per tal de poder ser incorporades en un sistema sense fils comercial a freqüència d'ones mil·limètriques. Per aquestes raons , diversos tipus d'estructures d'antenes han sigut proposats per aconseguir alta directivitat, conjuntament amb la capacitat d'apuntament del feix de radiació per les aplicacions anteriorment descrites a les bandes de 60, 79, i 94 GHz. La solució tradicionalment adoptada en aquests casos és estrictament basada en el sempre car, complexe, i aparatós concepte del phased-array. De fet, els phased-arrays tenen la capacitat de reconfigurar a gran velocitat feixos de radiació d'alta directivitat. Tot i això, el fet que requereixin la complexa integració de molts components cars a alta freqüència, amb certs nivells de pèrdues i aparatosos, com són els desfasadors d'estat sòlid, i les xarxes de conformació, fan d'aquesta solució inviable. La present tesis doctoral contribueix a l'estudi, des envolupament, i assaig experimental del rendiment de solucions d'antenes innovadores per tal de millorar les existents arquitectures d'antena a la banda freqüencial de les ones mil·limètriques, convenientment solucionant els problemes associats específicament als sistemes de comunicació de rang proper d'alta velocitat a 60 GHz (incloent els futurs sistemes 5G a mil·limètriques ), als sistemes de radar d'automoció a la banda dels 79 GHz, i als sistemes de comunicació, radar, i escaneig per aplicacions a 94 GHz. Els objectius específics perseguits en aquest treball acadèmic, focalitzats en definir una arquitectura d'antena alternativa, capaç d'aconseguir una completa reconfiguració i escaneig dels feixos de radiació en dues dimensions de l'espaia freqüències d'ona mil·limètriques , s'han plenament aconseguit. En aquest sentit, aquesta tesis doctoral s'ha dedicat essencialment a l'estudi en profunditat i desenvolupament pràctic de la part fonamental de l'innovador concepte del switched-beam array: noves lents dielèctriques inhomogenees de gradient d'índex amb estructura planar, les quals, tot i preservar una configuració física totalment plana, permeten una reconfiguració total en dues dimensions de l'espai de feixos de radiació d'alta directivitat. Un estudi transversal, que comprèn des de la investigació teòrica, passant per l'anàlisi numèric, noves metodologies i tècniques de fabricació, avaluació de rendiments, fins a una completa caracterització i assaig del rendiment en entorns reals d'aplicació de les noves arquitectures d'antena s'ha dut a terme amb total èxit.

The use of SMPS (Switched mode power supply) in embedded systems is continuously increasing. The technological requirements of these systems include simultaneously a very good voltage regulation and a strong compactness of components. SEPIC ( Single-Ended Primary Inductor Converter) is a DC/DC switching converter which possesses several advantages with regard to the other classical converters. Due to the difficulty in control of its 4th-order and non linear property, it is still not well-exploited. The objective of this work is the development of successful strategies of control for a SEPIC converter on one hand and on the other hand the effective implementation of the control algorithm developed for embedded applications (FPGA, ASIC) where the constraints of Silicon surface and the loss reduction factor are important. To do it, two non linear controls and two observers of states and load have been studied: a control and an observer based on the principle of sliding mode, a deadbeat predictive control and an Extended Kalman observer. The implementation of both control laws and the Extended Kalman observer are implemented in FPGA. An 11-bit digital PWM has been developed by combining a 4-bit Δ-Σ modulation, a 4-bit segmented DCM (Digital Clock Management) phase-shift and a 3-bit counter-comparator. All the proposed approaches are experimentally validated and constitute a good base for the integration of embedded switching mode converters

M.Ing.
This study considers improving the azimuth beam steering resolution of the circular Switched Parasitic Array (SPA) antennas (made up of dipoles) by a factor of two or more. In circular SPA antennas, beam steering is conventionally achieved by open-circuiting and shortcircuiting different parasitic elements and usually only one parasitic element is open-circuited at a time. However, such an approach results in low beam steering resolutions especially for the SPA antennas with few parasitic elements. In order to increase the azimuth beam steering resolution for the circular SPA antennas, two beam steering methods are proposed in this research work. In the first method, parasitic elements are open-circuited and short-circuited based on different combinations of the parasitic elements and the possible switch states. The proposed method was first validated by simulation tests using the MATLAB tool and WIPL-D. A prototype of the circular SPA antenna consisting of five elements was then implemented. It is noted that the simulation and measurement results match very well at 2.4 GHz. In order to have at least two combinations (from the first method) with almost similar gain and return loss, another simpler beam steering method was developed. The latter method is based on simultaneously open-circuiting either two or three neighbouring parasitic elements. The performance of the second method was studied through simulations using the circular SPA antenna geometries consisting of five, seven and nine elements. These geometries were first optimized (for gain and input impedance) and then modelled using WIPL-D. It was observed that the two methods double the azimuth beam steering resolution of the circular SPA antennas when compared to the conventional beam steering approaches of open-circuiting one parasitic element at a time. Variations in the structural parameters of the five elements circular SPA antenna at 2.4GHz were also investigated. In this procedure, the effects of variations (also considered as random errors) in the structural parameters (or antenna dimensions) on the performance of the SPA antennas were examined. Firstly, variations in each structural parameter were modelled with other structural parameters fixed as per specifications. Thereafter, effects of combined errors were also investigated. The simulation results demonstrated that variations in the structural parameter can either increase or decrease the gain and input impedance of the SPA antenna depending on the given specifications. The gain and input impedance sensitivities per variations in each structural parameter were computed to determine the degree at which the gain and input impedance can vary for a predefined change (error) in the structural parameter.

碩士
國立中央大學
電機工程學系
105
The goal of this study is to develop a low-profile smart antenna array for wireless communication applications to improve the transmission efficiency and the suppression of interferences. The proposed smart antenna array is implemented with compact switched beamformer modules and a patch antenna array. It can direct the main beam to different directions by providing the input of each antenna element with different phase. Microstrip patch antennas of center frequency f0 = 2.4 GHz is used for the antenna elements to achieve a low-profile design. First, three 4×1 linear antenna array designs with antenna spacings equal to 0.38 ,0.44 and 0.5 are implemented to evaluate the effect of antenna spacing on the radiation pattern IPD-based beamformer module. The module is mounted on the backside of antenna PCB to achieve beam steering. In order to achieve compact circuit size and low-profile, bridged-T coils are employed to realize the absorptive SP4T switch and the 4×4 Butler matrix of the IPD-based beamformer module.The measured input return loss of the 4×1 antenna array is better than 15 dB from 2.35 to 2.45 GHz, and the main beam can be successfully steered to 4 different directions. Also, it is found that the antenna spacing of 0.5 can achieve best side lobe suppression so it is used for the following proposed 4×4 planar patch array. Five proposed beamformer modules are employed to form the 2-D beamformer for the 4×4 patch antenna array with 16-beam directions. The measured input return loss of the 4×4 antenna array is better than 20 dB from 2.35 GHz to 2.45 GHz, it can successfully steer the main beam to sixteen pre-defined directions two-dimensionally. The size of the 2-D scanning antenna array is 320 mm × 312 mm with a low-profile of only 3.25 mm, which meets the design target of compact size and low-profile smart antenna system.

碩士
國立交通大學
電信工程系所
97
Ordinary leaky wave antenna has the advantages of broadband, high gain, and high directivity. Also, most of them have the function of frequency scanning. However, since single conductor leaky wave antenna is without actual ground, the radiation pattern is fixed in the end-fire direction. Thus, by making use of this characteristic, we arrange a fan-shaped antenna array, which results in sector radiation pattern while preserving the strengths of broadband, high gain, and end-fire radiation pattern. Finally, we present an efficient method to synthesize radiation patterns based on the antenna array theory. By changing the radius and spacing angle of fan-shaped antenna array appropriately, we can mold and obtain the desired half-power beamwidth of this antenna. Generally, the beam of beam-switched smart antenna does not change with frequency, which fits the nature of the mainbeam of single conductor leaky wave antenna. Therefore, we design two sets of smart antenna. Both are formed with four identical single conductor leaky wave fan-shaped antenna arrays placed in four different directions. The half-power beamwidth of the first and the second antenna array are 23°and 50° respectively. After adding a pair of SP4T switch, which we designed, we are able to switch the main beam of each array, which will allow the first and the second antenna arrays to cover a range of angle of 92° and 200° respectively. Related statistics, stimulation and the values of measurement will be presented.

碩士
國立臺灣大學
電信工程學研究所
105
This thesis presents the design and implementation of millimeter-wave dual-polarized antennas and arrays for 5G switched beam mobile communication applications. Two types of printed dual-polarized antennas with a maximum radiation in the broadside and the end-fire directions are investigated. Furthermore, we integrated the broadside and end-fire antennas into a compact dual-polarized 2 x 4 antenna array for millimeter-wave (mmW) multiple input multiple output (MIMO) mobile handset applications. We designed a 4 x 4 Butler Matrix and integrated with the developed mobile terminal antennas to achieve a switched beam 2 x 4 dual-polarized arrays. In the PCB design of Butler matrix in Ka-band, we compared the performances and feasibility of branch line coupler and the directional coupler before the integration with antennas. Additionally, for base station applications, we proposed the cube-shaped of base station antenna arrays with 4 x 4 broadside antennas for each side. The base station arrays therefore may cover four directional beams over the horizontal plane with features of high gain, high efficiency, and broad bandwidth. The proposed antenna designs are suitable for 5G mmW mobile communication applications with switched beam MIMO system.

碩士
國立交通大學
電子工程學系 電子研究所
104
Recently, low operating voltage and low power consumption for SoC system have become a solution to extend the lifespan of battery. In this case, power management unit is required to convert the output voltage produced by battery to proper dc voltage, and also provides from several uW up to several mW output power to loading circuits. However, in SoC system, any off-chip element will lead to not only the rising of cost, but also increase the difficulty of fully-integration on a multi-core chip. As a result, off-chip elements are not allowed, especially in SoC application. Therefore, fully-integrated dc-dc converter is an essential technique to be implemented in multi-core application and SoC system. In this thesis, the requirement of fully-integration is fulfilled by using switched-capacitor (SC) dc-dc converter. Besides, the topology of digital linear regulator (DLDO) is combined into the converter core circuit. The proposed SC circuit is able to scale output voltage by the characteristic of DLDO. In order to improve the effect of regulation, interleaving technique is utilized to reduce the output voltage ripple. Moreover, to reduce quiescent current, all the control circuits in this thesis are designed as digital circuits. The simulation results show that the proposed circuit is able to provide 86% peak conversion efficiency and remains more than 60% within the range of desired output voltage

Neste projeto de dissertação, foram avaliadas diferentes topologias de antenas, de forma a encontrar um design capaz de superar as dificuldades nas comunicações em alto mar. O impacto de várias variáveis de design é estudado, e os seus efeitos são explicados com bases em fundamentos teóricos. Para além disto, é desenvolvida uma rede de switching com oito setores, para que seja possível reconfigurar automaticamente a direção de transmissão da antena com o movimento do barco. A antena e as redes de alimentação e switching foram desenvolvidas e validadas recorrendo ao Finite Element Method no HFSS e ao Method of Moments no ADS, respetivamente. Os resultados medidos da unit cell, revelaram uma largura de banda fracional de 22.3 %, um isolamento entre os portos superior a 45 dB e um ganho de 7.5 dBi à frequência central de 5.15 GHz. Em simulação verificou-se que, uma vez ligada a antena à rede de switching, a largura de banda não foi alterada. Finalmente, os resultados experimentais foram comparados com os resultados de simulação, tanto do elemento unitário como do sistema como um todo.
In this dissertation work, different antenna topologies are evaluated to find the best design capable of overcoming the difficulties of communications at high seas. The impact of multiple design variables is studied, and their effects explained resorting to theoretical principles. Furthermore, a switching matrix of eight sectors is also designed, so the antenna beam direction can be automatically reconfigured with the movement of the vessel. The antenna and both the feeding and switching networks were designed and validated resorting to Finite Element Method in HFSS and the Method of Moments in ADS, respectively. The final antenna element experimental results show a fractional impedance bandwidth of 22.3 %, an isolation between inputs above 45 dB and a gain of 7.5 dBi at the centre frequency of 5.15 GHz. Through simulation, it is shown that when the unit element is connected to the switching network, the fractional bandwidth remains unchanged. Finally, the experimental measurements were compared with the simulated results of the unit cell and the entire system.

Neste projeto de dissertação, foram avaliadas diferentes topologias de antenas, de forma a encontrar um design capaz de superar as dificuldades nas comunicações em alto mar. O impacto de várias variáveis de design é estudado, e os seus efeitos são explicados com bases em fundamentos teóricos. Para além disto, é desenvolvida uma rede de switching com oito setores, para que seja possível reconfigurar automaticamente a direção de transmissão da antena com o movimento do barco. A antena e as redes de alimentação e switching foram desenvolvidas e validadas recorrendo ao Finite Element Method no HFSS e ao Method of Moments no ADS, respetivamente. Os resultados medidos da unit cell, revelaram uma largura de banda fracional de 22.3 %, um isolamento entre os portos superior a 45 dB e um ganho de 7.5 dBi à frequência central de 5.15 GHz. Em simulação verificou-se que, uma vez ligada a antena à rede de switching, a largura de banda não foi alterada. Finalmente, os resultados experimentais foram comparados com os resultados de simulação, tanto do elemento unitário como do sistema como um todo.
In this dissertation work, different antenna topologies are evaluated to find the best design capable of overcoming the difficulties of communications at high seas. The impact of multiple design variables is studied, and their effects explained resorting to theoretical principles. Furthermore, a switching matrix of eight sectors is also designed, so the antenna beam direction can be automatically reconfigured with the movement of the vessel. The antenna and both the feeding and switching networks were designed and validated resorting to Finite Element Method in HFSS and the Method of Moments in ADS, respectively. The final antenna element experimental results show a fractional impedance bandwidth of 22.3 %, an isolation between inputs above 45 dB and a gain of 7.5 dBi at the centre frequency of 5.15 GHz. Through simulation, it is shown that when the unit element is connected to the switching network, the fractional bandwidth remains unchanged. Finally, the experimental measurements were compared with the simulated results of the unit cell and the entire system.

Neste projeto de dissertação, foram avaliadas diferentes topologias de antenas, de forma a encontrar um design capaz de superar as dificuldades nas comunicações em alto mar.O impacto de várias variáveis de design é estudado, e os seus efeitos são explicados com bases em fundamentos teóricos.Para além disto, é desenvolvida uma rede de switching com oito setores, para que seja possível reconfigurar automaticamente a direção de transmissão da antena com o movimento do barco.A antena e as redes de alimentação e switching foram desenvolvidas e validadas recorrendo ao Finite Element Method no HFSS e ao Method of Moments no ADS, respetivamente.Os resultados medidos da unit cell, revelaram uma largura de banda fracional de 22.3 %, um isolamento entre os portos superior a 45 dB e um ganho de 7.5 dBi à frequência central de 5.15 GHz. Em simulação verificou-se que, uma vez ligada a antena à rede de switching, a largura de banda não foi alterada.Finalmente, os resultados experimentais foram comparados com os resultados de simulação, tanto do elemento unitário como do sistema como um todo.
In this dissertation work, different antenna topologies are evaluated to find the best design capable of overcoming the difficulties of communications at high seas.The impact of multiple design variables is studied, and their effects explained resorting to theoretical principles.Furthermore, a switching matrix of eight sectors is also designed, so the antenna beam direction can be automatically reconfigured with the movement of the vessel.The antenna and both the feeding and switching networks were designed and validated resorting to Finite Element Method in HFSS and the Method of Moments in ADS, respectively. The final antenna element experimental results show a fractional impedance bandwidth of 22.3 %, an isolation between inputs above 45 dB and a gain of 7.5 dBi at the centre frequency of 5.15 GHz. Through simulation, it is shown that when the unit element is connected to the switching network, the fractional bandwidth remains unchanged. Finally, the experimental measurements were compared with the simulated results of the unit cell and the entire system.

Cheung Chak Chung.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2001.
Includes bibliographical references (leaves 101-114).
Abstracts in English and Chinese.
Abstract --- p.i
Acknowledgments --- p.iii
Vita --- p.v
Table of Contents --- p.vi
List of Figures --- p.x
List of Tables --- p.xiv
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Motivation --- p.1
Chapter 1.2 --- Aims and Contribution --- p.4
Chapter 1.3 --- Thesis Overview --- p.5
Chapter 2 --- VLSI Design Cycle --- p.6
Chapter 2.1 --- Logic Synthesis --- p.7
Chapter 2.1.1 --- Logic Minimization --- p.8
Chapter 2.1.2 --- Technology Mapping --- p.8
Chapter 2.1.3 --- Testability --- p.8
Chapter 2.2 --- Physical Design Synthesis --- p.8
Chapter 2.2.1 --- Partitioning --- p.9
Chapter 2.2.2 --- Floorplanning & Placement --- p.10
Chapter 2.2.3 --- Routing --- p.11
Chapter 2.2.4 --- "Compaction, Extraction & Verification" --- p.12
Chapter 2.2.5 --- Physical Design of FPGAs --- p.12
Chapter 3 --- Alternative Wiring --- p.13
Chapter 3.1 --- Introduction --- p.13
Chapter 3.2 --- Notation and Definitions --- p.15
Chapter 3.3 --- Application of Rewiring --- p.17
Chapter 3.3.1 --- Logic Optimization --- p.17
Chapter 3.3.2 --- Timing Optimization --- p.17
Chapter 3.3.3 --- Circuit Partitioning and Routing --- p.18
Chapter 3.4 --- Logic Optimization Analysis --- p.19
Chapter 3.4.1 --- Global Flow Optimization --- p.19
Chapter 3.4.2 --- OBDD Representation --- p.20
Chapter 3.4.3 --- Automatic Test Pattern Generation (ATPG) --- p.22
Chapter 3.4.4 --- Graph Based Alternative Wiring (GBAW) --- p.23
Chapter 3.5 --- Augmented GBAW --- p.26
Chapter 3.6 --- Logic Optimization by using GBAW --- p.28
Chapter 3.7 --- Conclusions --- p.31
Chapter 4 --- Multi-way Partitioning using Rewiring Techniques --- p.33
Chapter 4.1 --- Introduction --- p.33
Chapter 4.2 --- Circuit Partitioning Algorithm Analysis --- p.38
Chapter 4.2.1 --- The Kernighan-Lin (KL) Algorithm --- p.39
Chapter 4.2.2 --- The Fiduccia-Mattheyses (FM) Algorithm --- p.42
Chapter 4.2.3 --- Geometric Representation Algorithm --- p.46
Chapter 4.2.4 --- The Multi-level Partitioning Algorithm --- p.49
Chapter 4.2.5 --- Hypergraph METIS - hMETIS --- p.51
Chapter 4.3 --- The GBAW Partitioning Algorithm --- p.53
Chapter 4.4 --- Experimental Results --- p.56
Chapter 4.5 --- Conclusions --- p.58
Chapter 5 --- Optimum FPGA Switch-Box Designs - HUSB --- p.62
Chapter 5.1 --- Introduction --- p.62
Chapter 5.2 --- Background and Definitions --- p.65
Chapter 5.2.1 --- Routing Architectures --- p.65
Chapter 5.2.2 --- Global Routing --- p.67
Chapter 5.2.3 --- Detailed Routing --- p.67
Chapter 5.3 --- FPGA Router Comparison --- p.69
Chapter 5.3.1 --- CGE --- p.69
Chapter 5.3.2 --- SEGA --- p.70
Chapter 5.3.3 --- TRACER --- p.71
Chapter 5.3.4 --- VPR --- p.72
Chapter 5.4 --- Switch Box Design --- p.73
Chapter 5.4.1 --- Disjoint type switch box (XC4000-type) --- p.73
Chapter 5.4.2 --- Anti-symmetric switch box --- p.74
Chapter 5.4.3 --- Universal Switch box --- p.74
Chapter 5.4.4 --- Switch box Analysis --- p.75
Chapter 5.5 --- Terminology --- p.77
Chapter 5.6 --- "Hyper-universal (4, W)-design analysis" --- p.82
Chapter 5.6.1 --- "H3 is an optimum (4, 3)-design" --- p.84
Chapter 5.6.2 --- "H4 is an optimum (4,4)-design" --- p.88
Chapter 5.6.3 --- "Hi is a hyper-universal (4, i)-design for i = 5,6,7" --- p.90
Chapter 5.7 --- Experimental Results --- p.92
Chapter 5.8 --- Conclusions --- p.95
Chapter 6 --- Conclusions --- p.99
Chapter 6.1 --- Thesis Summary --- p.99
Chapter 6.2 --- Future work --- p.100
Chapter 6.2.1 --- Alternative Wiring --- p.100
Chapter 6.2.2 --- Partitioning Quality --- p.100
Chapter 6.2.3 --- Routing Devices Studies --- p.100
Bibliography --- p.101
Chapter A --- 5xpl - Berkeley Logic Interchange Format (BLIF) --- p.115
Chapter B --- Proof of some 2-local patterns --- p.122
Chapter C --- Illustrations of FM algorithm --- p.124
Chapter D --- HUSB Structures --- p.127
Chapter E --- Primitive minimal 4-way global routing Structures --- p.132

Zhou Lin.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.
Includes bibliographical references (leaves 50-53).
Abstracts in English and Chinese.
Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Motivation --- p.1
Chapter 1.2 --- Aims and Contribution --- p.3
Chapter 1.3 --- Thesis Overview --- p.4
Chapter 2 --- Field-Programmable Gate Array and Routing Algorithm in VPR --- p.6
Chapter 2.1 --- Commercially Available FPGAs --- p.6
Chapter 2.2 --- FPGA Logic Block Architecture --- p.7
Chapter 2.2.1 --- Logic Block Functionality vs. FPGA Area-Efficiency --- p.7
Chapter 2.2.2 --- Logic Block Functionality vs. FPGA Delay-Performance --- p.7
Chapter 2.2.3 --- Lookup Table-Based FPGAs --- p.8
Chapter 2.3 --- FPGA Routing Architecture --- p.8
Chapter 2.4 --- Design Parameters of FPGA Routing Architecture --- p.10
Chapter 2.5 --- CAD for FPGAs --- p.10
Chapter 2.5.1 --- Synthesis and Logic Block Packing --- p.11
Chapter 2.5.2 --- Placement --- p.11
Chapter 2.5.3 --- Routing --- p.12
Chapter 2.5.4 --- Delay Modelling --- p.13
Chapter 2.5.5 --- Timing Analysis --- p.13
Chapter 2.6 --- FPGA Programming Technologies --- p.13
Chapter 2.7 --- Routing Algorithm in VPR --- p.14
Chapter 2.7.1 --- Pathfinder Negotiated Congestion Algorithm --- p.14
Chapter 2.7.2 --- Routing Algorithm Used by VPR --- p.16
Chapter 3 --- Connection-Switch Box Design --- p.17
Chapter 3.1 --- Introduction --- p.17
Chapter 3.2 --- Connection-Switch Box Design Algorithm --- p.19
Chapter 3.2.1 --- Connection between Logic Pins and Tracks --- p.20
Chapter 3.2.2 --- Connection between Pad Pins and Tracks --- p.25
Chapter 3.3 --- Switch Number Comparisons --- p.26
Chapter 3.4 --- Experimental Results --- p.29
Chapter 3.5 --- Summary --- p.32
Chapter 4 --- Optimal MST-Based Graph Algorithm on FPGA Segmenta- tion Design --- p.37
Chapter 4.1 --- Introduction --- p.37
Chapter 4.2 --- MST-Based Graph Algorithm on FPGA Channel Segmentation Design --- p.39
Chapter 4.2.1 --- Net Merging Problem of Row-Based FPGAs --- p.41
Chapter 4.2.2 --- Extended Net Merging Problem of Symmetrical Array FPGAs --- p.44
Chapter 4.3 --- Experimental Results --- p.46
Chapter 4.4 --- Summary --- p.46
Chapter 5 --- Conclusions --- p.48
Bibliography --- p.50

碩士
國立臺北科技大學
電腦與通訊研究所
94
The Butler matrix is a kind of feeding networks for switched-beam antenna array system, and it consisted of 3dB-hybrid couplers. The characteristic of hybrid couplers have to be the same. Generally, the 3dB-hybrid coupler is a narrow band element, so that it can be used as a feeding structure on Butler matrix. Because of the narrow band of 3dB-hybrid couplers, the Butler matrix is also a narrow band feeding network for wireless communication systems. The design of a wideband four-port Butler matrix was proposed. The Butler matrix that was proposed has a wider bandwidth, so the wideband microwave component, 3dB- hybrid coupler, was designed. Implementation of this Butler matrix can be used to feed a switched-beam antenna array for 3G and wireless applications from 1.9GHz to 2.5GHz. The measured sidelobe level is below -10dB or so.

No
A new approach in achieving beam steering in array antenna is introduced using the genetic algorithm optimization. The binary switching technique uses simple binary ON/OFF diodes placed in the feeding network of the array element to achieve beam steering. Constantly feeding the driven element and continuous binary variation of the ON/OFF state of each parasitic array elements which determines its conducting ability defines a beam steering angle. Each beam steered angle is distinguished by series of binary combination determined by the genetic algorithm. A uniform circular array antenna consisting of 13 elements is used to implement this technique. The simulation and result analysis of the binary switched array is presented with several beam steering angles scanned.