Co-design of Reconfigurable and Multifunction Passive RF/Microwave Components

In order to meet the market demands, multi-band communication systems that are able to accommodate different wireless technologies to be compatible with different wireless standards should be investigated and realized. Multifunction and multi-band RF front-end components are promising solutions for reducing the size and enhancing the performance of multi-band communication systems. This dissertation focuses on the design and implementation of different multifunction and tunable microwave components for use in multi-standard, flexible transceiver. For frequency-domain duplexing (FDD) communication systems, in which the uplink and downlink channels are carried on different RF frequencies, a diplexer is an essential component to separate the transmitting and receiving signals from the antenna. Electrically tunable diplexers simplify the architecture of reconfigurable RF-front end. Moreover, in modern communication systems, the crowding of the spectrum and the scaling of electronics can result in higher common-mode interference and even-order non-linearity issues. In this dissertation, three tunable compact SIW-based dual-mode diplexers, with various SE (single-ended) and BAL (balanced) capabilities, are introduced for the first time. The dual-mode operation results in a dependent tuning between the two ports. The presented designs are for SE-SE, SE-BAL, and BAL-BAL. However, based on the presented design concepts, any combination of the diplexer ports can be achieved in terms of supporting the balanced and single-ended system interface. The fabricated diplexers show low insertion loss, high isolation, good tuning range and high common mode rejection. Tunable bandstop filter (BSF) is one of the essential components in the design of RF front-ends that require wide-band operations. A wide-open front-end leaves the receiver vulnerable to jamming by high-power signals. As a result, this type of front-ends requires dynamic isolation of any interfering signal. Realization of such filters in a balanced configuration, as a second function, is an important step in the realization of full-balanced RF front-ends. Balanced (differential) circuits have many important advantages over unbalanced (single-ended) circuits such as immunity to system noise, reduction of transient noise generation and inherent suppression of even-order nonlinearities. All reported balanced filters are bandpass filters that target wide pass-bands and high common-mode rejection. These filters are necessary for wide-band RF front-ends but, as mentioned above, leave the system open to interferers and jammers. In this dissertation, a new differential coupling structure for evanescent-mode cavity resonators is developed, enabling the design of fully-balanced tunable BSF. The proposed filter is tunable from 1.57-3.18 GHz with 102% tuning range. In addition, over the full range, the measured 10-dB fractional bandwidth ranges from 1-2.4%, and the attenuation level is better than 47 dB. Lastly, Substrate Integrated Waveguide (SIW) evanescent-mode cavity resonators (EVA) are employed in the design of RF couplers, quadrature hybrid and rat-race couplers. These couplers are used in the design of numerous RF front-end components such as power amplifiers, balanced mixers, and antenna array feeding networks. Utilizing such resonators (EVA) in the design allows the couplers to have wide spurious-free range, low power consumption, high power handling capability and both tunability and filtering capabilities. The proposed quadrature hybrid coupler can be tuned starting from 1.32–2.22 GHz with a measured insertion loss range from 1.29 to 0.7 dB. The measured reflection and isolation are better than 12 dB and 17 dB, respectively. Moreover, the coupler has a measured spurious free range of 5.1–3fo (lowest–highest frequency). Regarding rat-race coupler, two designs are introduced. The first design is based on a full-mode cavity while the second one is more compact and based on a half-mode cavity. Both designs show more than 70% tuning range, and the isolation is better than 30 dB

Wideband two-dimensional and multiple beam phased arrays and microwave applications using piezoelectric transducers

Modern satellite, wireless communication, and radar systems often demand wideband performance for multi-channel operation and the ability to steer multiple beams for multiple moving targets. This dissertation covers a variety of topics to design low-cost and wideband antenna systems. The main areas of study are microwave devices controlled piezoelectric transducers (PETs) and wideband baluns and balanced microwave circuits using parallel-strip lines. Some focus has also been given to the design of Rotman lens for multiple beam generation and Vivaldi antenna arrays for wideband two-dimensional scanning. The dielectric perturbation technique controlled by PET is introduced to design a wideband phase shifter and a QPSK modulator, and to tune the resonant frequency of a slot dipole. The designed PET-controlled phase shifters are used for beam steering in a dual beam phased array using a bidirectional feeding scheme and a five-beam phased array using a microstrip Rotman lens. Vivaldi-type antennas are commonly used to achieve wideband performance. Very wideband performance can be achieved using an antipodal tapered slot antenna because of its inherent simple wideband transition from microstrip line to parallel-strip line. An antipodal tapered slot antenna and a phased array are designed to span 10 to 35 GHz. In addition, a 4??4 two-dimensional antenna array is designed using wideband antipodal tapered slot antennas, and two sets of PET-controlled phase shifters for E- and H-plane scanning are fabricated to steer the beam. As a microwave system using wideband antenna array, a new low-cost and wideband phased array radar is developed using a modulated pulse over 8 to 20 GHz band. The double-sided parallel-strip line as a balanced line is presented. The parallelstrip line offers much flexibility for microwave circuit designs. This transmission line makes it possible to realize a low impedance line and allows the design of a compact wideband balun and junction. Wideband transitions (or baluns) from parallel-strip line to microstrip line, a typical unbalanced transmission line, are realized to cover several octave bandwidth. Balanced microwave filters and a hybrid coupler are developed using the parallel-strip line

Impedance Transformers

Non

Tatsuo Itoh : discurs llegit a la cerimònia d'investidura celebrada a la Sala d'Actes del Rectorat el dia 14 d'octubre de l'any 2015

Tatsuo Itoh va ser investit doctor honoris causa per la UAB per les seves rellevants contribucions a l'enginyeria de radiofreqüència/microones i de les telecomunicacions.Nomenament 19/03/2015. A proposta de l'Escola d'Enginyeria. L'acte d'investidura va tenir lloc el 14 d'octubre de 201

Multifunction Transceiver Architecture and Technology for Future Wireless Systems

RÉSUMÉ Depuis la toute première transmission sans fil, les ondes radiofréquences ont été progressivement mises en valeur et exploitées dans un nombre de plus en plus important d'applications. Parmi toutes ces applications, la détection et la télécommunication sont sans doute les plus indispensables de nos jours. Il existe un grand nombre d’utilisations des radiofréquences, incluant les transports intelligents pour lesquels les véhicules doivent être équipés à la fois de radars et de dispositifs de communication afin d’être capables de détecter l'environnement ainsi que de réaliser la communication avec d'autres unités embarquées. La technologie émergente 5G est un autre exemple pour lequel plusieurs capteurs et radios devraient être capables de coopérer de manière autonome ou semi-autonome. Les principes de fonctionnement des systèmes radars et radio sont toutefois différents. Ces différences fondamentales peuvent entraîner l'utilisation de différentes architectures de traitement du signal et d'émetteur-récepteur, ce qui peut poser des problèmes pour l'intégration de toutes les fonctions requises au sein d'une seule et même plate-forme. En dehors de cela, certaines applications requièrent plusieurs fonctions simultanément dans un même dispositif. Par exemple, les systèmes de détection d'angle d'arrivée 2D nécessitent d'estimer l'angle d'arrivée (AOA) du faisceau entrant dans les plans horizontal et vertical simultanément. La communication radio multi-bandes et multi-modes est un autre exemple pour lequel un système radio doit être capable de communiquer dans plusieurs bandes de fréquences et dans plusieurs modes, par exemple, un duplexage en fonction de la fréquence ou du temps. À première vue, on peut penser que l'assemblage de plusieurs dispositifs distincts n'est pas la meilleure solution en ce qui concerne le coût, la simplicité et la fonctionnalité. Par conséquent, une direction de recherche consiste à proposer une architecture d'émetteur-récepteur unifiée et compacte plutôt qu’une plate-forme assemblant de multiples dispositifs distincts. C’est cette problématique qui est spécifiquement abordée dans ce travail. Selon les fonctions à intégrer dans un seul et unique système multifonctionnel, la solution peut traiter plusieurs aspects simultanément. Par exemple, toute solution réalisant l'intégration de fonctions liées au radar et à la radio devrait traiter deux aspects principaux, à savoir : la forme d'onde opérationnelle et l'architecture frontale RF.----------ABSTRACT Since the very early wireless transmission of radiofrequency signals, it has been gradually flourished and exploited in a wider and wider range of applications. Among all those applications of radio technology, sensing and communicating are undoubtedly the most indispensable ones. There are a large number of practical scenarios such as intelligent transportations in which vehicles must be equipped with both radar and communication devices to be capable of both sensing the environment and communication with other onboard units. The emerging 5G technology can be another important example in which multiple sensors and radios should be capable of cooperating with each other in an autonomous or semi-autonomous manner. The operation principles of these radar and radio devices are different. Such fundamental differences can result in using different operational signal, distinct signal processing, and transceiver architectures in these systems that can raise challenges for integration of all required functions within a single platform. Other than that, there exist some applications where several functions of a single device (i.e. sensor or radio) are required to be executed simultaneously. For example, 2D angle-of-arrival detection systems require estimating the angle of arrival (AOA) of the incoming beam in both horizontal and vertical planes at the same time. Multiband and multimode radio communication is another example of this kind where a radio system is desired to be capable of communication within several frequency bands and in several modes, e.g., time or frequency division duplexing. At a first glance, one can feel that the mechanical assembling of several distinct devices is not the best solution regarding the cost, simplicity and functionality or operability. Hence, the research attempt in developing a rather unified and compact transceiver architecture as opposed to a classical platform with assembled multiple individual devices comes out of horizon, which is addressed specifically in this work. Depending on the wireless functions that are to be integrated within a single multifunction system, the solution should address multiple aspects simultaneously. For instance, any solution for integrating radar and radio related functions should be able to deal with two principal aspects, namely operational waveform and RF front-end architecture. However, in some other above- mentioned examples such as 2D DOA detection system, identical operational waveform may be used and the main challenge of functional integration would pertain to a unification of multiple mono-functional transceivers

Microwave filtering amplifiers

Filtering microwave amplifiers have become a topic of interest because of the need for devices capable of isolating the system itself and avoiding interference from other systems. Key subsystems in communication receivers and transmitters are the microwave amplifiers, either low-noise amplifiers (LNA) or solid-state power amplifiers (SSPA). Different topologies have been proposed in the last years and a big research effort has been devoted to filtering structures, either in the input matching network (IMN) or output matching network (OMN). The subject of study of this master thesis is the design of a filtering microwave amplifier to be operated at 4 GHz. As a continuation of my bachelor final project -where the subject of study was the design of a frequency-switchable microwave amplifier that could be operated at three different frequencies (3.2 GHz, 4 GHz and 4.8 GHz) in the 5G band- this master thesis proposes a methodology to improve the filtering capabilities of such components. To this end, several filtering structures are studied, taking into account the trade-off between performance and circuit size. The theoretical design procedure is studied, providing insights in the problems that can appear for different filtering topologies. The IMN is based on a simple line-stub structure, and the OMN is a filtering structure which is simulated and fabricated in multiple forms to provide insights in the structures available. The amplifier behavior is simulated using circuit and 2.5D electromagnetic simulations and optimized. The amplifier was fabricated on a conventional microwave substrate, and its S parameters and noise figure were measured and compared to simulations, showing a good agreement with simulations.Los amplificadores de microondas se han convertido en un tema de interés a causa de la necesidad de componentes capaces de aislar el sistema frente a interferencias de otros circuitos. Un ejemplo de subsistemas destacables en transmisores y receptores de comunicación son los amplificadores de microondas, tanto de bajo ruido (LNA) como de potencia (PA). Durante los últimos años se han propuesto diferentes tipos de filtraje y se ha invertido mucha investigación en los componentes, tanto en la red de adaptación de entrada (IMN) como de salida (OMN). El tema de estudio de esta tesis de máster es el diseño de un amplificador de microondas filtrante a la frecuencia de 4 GHz. Como continuación de mi trabajo de fin de grado \cite{TFGPol} -donde el tema de estudia era el diseño de un amplificador de microondas conmutable que se podía utilizar a tres frecuencias distintas (3.2 GHz, 4 GHz y 4.8 GHz) en la banda de 5G-, esta tesis de máster propone una metodología para mejorar las capacidades filtrantes de estos componentes. Con este objetivo, se estudian diversas estructuras filtrantes, teniendo en cuenta el balance entre resultados y tamaño del circuito. Se estudia el método de diseño teórico, aportando detalles sobre los problemas que pueden aparecer en diversas tipologías de filtro. La red de entrada (IMN) se basa en una estructura simple de línea-stub y la red de salida (OMN) es una estructura filtrante, que es simulada y fabricada utilizando diferentes formas para aportar detalles sobre las diversas estructuras disponibles. Se ha simulado el comportamiento del amplificador utilizando simulaciones 2.5D electromagnéticas y se ha optimizado. El amplificador se fabricó en un sustrato de microondas convencional y sus parámetros S y factor de ruido F fueron medidos y comparados con las simulaciones, mostrando una buena concordancia entre ambos resultados.Els amplificadors filtrants de microones s'han convertit en un tema d'interès a causa de la necessitat de components capaços d'aïllar el sistema d'interferències d'altres circuits. Un exemple de subsistemes destacables en transmissors i receptors de comunicacions són els amplificadors de microones, tant de baix soroll (LNA) com de potència (PA). Durant els últims anys s'han proposat diferents estructures filtrants i s'ha dut a terme molta investigació, tant en les xarxes d'entrada (IMN) com en les xarxes de sortida (OMN). El tema d'estudi d'aquesta tesi de màster és el disseny d'un amplificador de microones filtrant a la freqüència de 4 GHz. Com a continuació del meu treball de fi de grau -on el tema d'estudi era el disseny d'un amplificador de microones commutable que es podia utilitzar a tres freqüències diferents (3.2 GHz, 4 GHz i 4.8 GHz) a la banda de 5G-, aquesta tesi de màster proposa una metodologia per millorar les capacitats filtrants d'aquests components. Amb aquest objectiu, s'estudien diverses estructures filtrants, tenint en compte el balanç entre resultats i mida del circuit. S'estudia el mètode de disseny teòric, aportant detalls sobre els problemes que poden aparèixer en diverses tipologies de filtre. La xarxa d'entrada (IMN) es basa en una estructura simple de línia-stub i la xarxa de sortida (OMN) és una estructura filtrant, que és simulada i fabricada utilitzant diverses formes per aportar detalls sobre les diverses estructures disponibles. S'ha simulat el comportament de l'amplificador utilitzant simulacions 2.5D electromagnètiques i s'ha optimitzat. S'ha fabricat l'amplificador utilitzant un substrat de microones convencional i els seus paràmetres S i factor de soroll F s'han mesurat comparats amb les simulacions, mostrant una bona concordança entre ambdós resultats