Análisis de circuitos innovadores basados en osciladores para radar, RFID y sistemas reconfigurables
En la presentación se mostrarán avances en el análisis y diseño de circuitos compactos y de bajo consumo para radar de bajo coste, RFID y sistemas reconfigurables. Las nuevas topologías aprovechan la capacidad de los circuitos osciladores de combinar la generación de señal con otras funciones, como el mezclado de frecuencia o el desfasaje. Sin embargo, esta compactación de funciones incrementa la complejidad de operación, ya que deben satisfacerse simultáneamente varias condiciones matemáticas en un sistema de carácter autónomo. Entre los circuitos analizados se encuentra el radar auto-inyectado, en el que la señal transmitida por un oscilador es reflejada por un blanco en movimiento y reinyectada en el mismo oscilador con una modulación de fase, inducida por dicho movimiento. Se considerarán también lectores RFID compactos y de bajo costo. La señal del oscilador, controlada mediante un generador de rampa, es transmitida por la antena y la variación en la impedancia de carga equivalente, inducida por los resonadores que implementan la secuencia de bits de la etiqueta, da lugar a una modulación de frecuencia, fácilmente detectable. En la charla se presentará una nueva metodología de análisis de estos circuitos que utiliza un modelo de oscilador extraído de simulaciones de balance armónico y expresiones analíticas intuitivas para la descripción matemática de la interacción del oscilador con el entorno. Otro ejemplo de implementaciones compactas son las basadas en osciladores súper-regenerativos, capaces de remplazar costosas cadenas amplificadoras en receptores utilizando los altos valores de ganancia que permite el crecimiento exponencial inicial de la oscilación. Se presentará un método de análisis basado en la extracción de una función de transferencia lineal y variante en el tiempo, definida en el dominio de la envolvente. Finalmente, se considerará el caso de los osciladores reconfigurables sin conmutador, con interés en sistemas de comunicación multibanda.
Almudena Suárez es la directora del grupo de investigación Ingeniería de Microondas y Radiocomunicaciones de la Universidad de Cantabria. Es “Fellow” de IEEE desde 2012 y fue “IEEE Distinguished Microwave Lecturer” en el periodo 2006-2008. Ha publicado 82 artículos en revistas de IEEE y 57 en IEEE T-MTT. Es autora de Analysis and Design of Autonomous Microwave Circuits, Wiley-IEEE Press, 2009. Almudena Suárez fue coordinadora del área de Tecnología Electrónica y de Comunicaciones (TEC) de la Agencia Nacional de Evaluación y Prospectiva (ANEP) entre 2009 y 2013. Fue presidenta del congreso IEEE Topical Conference on Power Amplifiers (PAWR) en 2014 y 2015 y General TPC Chair de European Microwave Week de 2018. Es miembro del Board of Directors (BoD) de European Microwave Association (EuMA). Es actualmente “Publication Chair” de EuMA. Ha impartido numerosas charlas invitadas en Europa, Estados Unidos y Asia y múltiples cursos cortos asociados con IEEE International Microwave Symposium y otros congresos de IEEE.
Many names, many advantages – Are resonant cavity antennas the killer planar space-saving approach to get 15-25 dBi gain?
No other antenna concept has more names. At present these antennas are known as Fabry-Perot cavity resonator antennas, Partial Reflector Surface (PRS) based antennas, Electromagnetic Band Gap (EBG) Resonator antennas (ERAs) and Two-Dimensional Leaky-Wave Antennas, and more names are forthcoming. Yet they all have more or less the same configuration consisting of a resonant cavity, formed between a partially reflecting superstructure and a fully reflecting (ground) plane. The resonant cavity is excited by a small feed antenna. Hence, they are referred to as resonant cavity antennas (RCAs) in this presentation. Since the concept of using a “partially reflecting sheet array” superstructure to significantly enhance the directivity was disclosed by Trentini in 1956, it has been an attractive concept to several antenna researchers for several reasons, including its theoretical elegance, relationships to other well-researched area such as leaky-waves, EBG, frequency selective surfaces and metasurfaces, and practical advantages as a low-cost simple way to achieve high-gain (15-25 dBi) from an efficient planar antenna without an array, which requires a feed network. The RCA concept is one of the main beneficiaries of the surge of research on electromagnetic periodic structures in the last decade, first inspired by EBG and then to some extent by metamaterials. As a result, RCAs gained a tremendous improvement in performance in the last 10 years, in addition to other advantages such as size reduction. As an example, achieving 10% gain bandwidth from such an antenna with a PSS was a major breakthrough in 2006 but now there are prototypes with gain bandwidths greater than 50%. Until recently most RCAs required an area in the range of 25-100 square wavelengths but the new extremely wideband RCAs are very compact, requiring only 1.5-2 square wavelengths at the lowest operating frequency. Once limited to a select group of researchers, these advantages have attracted many new researchers to RCA research domain, and the list is growing fast, as demonstrated by the diversity of authors in recent RCA publications. RCAs have already replaced other types of antennas, for example as feeds for reflectors. Several methods have been developed to steer the beam of RCAs. Have they become the killer planar alternative to 3D antennas such as horns and small reflectors? What is the difference between RCS and lens antennas? Will RCAs make lens antennas redundant? Starting from historical achievements of RCA technology, this keynote presentation will take the audience through various aspects and developments of RCA technology, while attempting to answer aforementioned questions. It will conclude with a illustration of a new highly-efficient, low-cost method to steer the beam of an RCA over a wide angular range in both azimuth and elevation planes, which is applicable to not only RCAs but also any aperture-type medium- or high-gain antenna with a fixed beam.
Professor Karu Esselle, IEEE ‘M (1992), SM (1996), F (2016), received BSc degree in electronic and telecommunication engineering with First Class Honours from the University of Moratuwa, Sri Lanka, and MASc and PhD degrees in electrical engineering from the University of Ottawa, Canada. He is a Professor of Electronic Engineering, Macquarie University, Sydney, Past Director of WiMed Research Centre and Past Associate Dean – Higher Degree Research (HDR) of the Division of Information and Communication Sciences. He has also served as a member of the Dean’s Advisory Council and the Division Executive and as the Head of the Department several times. In 2018, he has been selected to chair the prestigious Distinguished Lecturer Program Committee of the IEEE Antennas and Propagation (AP) Society and in 2019 he was re-selected for the same position. After two stages in the selection process, Karu was also selected by this Society as one of two candidates in the ballot for 2019 President of the Society. Karu is also one of the three Distinguished Lecturers (DL) selected by the Society in 2016. Karu is also the Chair of the Board of management of Australian Antenna Measurement Facility, and was the elected Chair of both IEEE New South Wales (NSW), and IEEE NSW AP/MTT Chapter, in 2016 and 2017. He directs the Centre for Collaboration in Electromagnetic and Antenna Engineering. Karu was elevated to IEEE Fellow grade for his contributions to resonance-based antennas. He is also a Fellow of Engineers Australia.
Karu has authored approximately 600 research publications and his papers have been cited about 8,000 times. He is the first Australian antenna researcher ever to reach Google Scholar h-index of 30 and his current i10 index (158 in May 2019) and h-index (41 in May 2019) is often among the top Australian antenna researchers. Since 2002, his research team has been involved with research grants, contracts and PhD scholarships worth over 18 million dollars, including 15 Australian Research Council grants. His research has been supported by many national and international organisations including Australian Research Council, Intel, US Air Force, Cisco Systems, Hewlett-Packard, Australian Department of Defence, Australian Department of industry, and German and Indian governments.
Karu is in the College of Expert Reviewers of the European Science Foundation (2019-22) and he has been invited to serve as an international expert/research grant assessor by several other research funding bodies as well, including European Research Council and national agencies in the Netherlands, Canada, Finland, Hong-Kong, Georgia, South Africa and Chile. He has been invited by Vice-Chancellors of Australian and overseas universities to assess applications for promotion to professorial levels.
Karu’s awards include 2019 Motohisa Kanda Award for the most cited paper in IEEE Transactions EMC in the past five years, 2019 ARC Discovery International Award, 2017 Excellence in Research Award from the Faculty of Science and Engineering, 2017 Engineering Excellence Award for Best Innovation, 2017 Certificate of Recognition from IEEE Region 10, 2016 and 2012 Engineering Excellence Awards for Best Published Paper from IESL NSW Chapter, 2011 Outstanding Branch Counsellor Award from IEEE headquarters (USA), 2009 Vice Chancellor’s Award for Excellence in Higher Degree Research Supervision and 2004 Innovation Award for best invention disclosure. His mentees have been awarded many fellowships, awards and prizes for their research achievements. Forty-eight international experts who examined the theses of his recent PhD graduates ranked them in the top 5% or 10%.
Karu has provided expert assistance to more than a dozen companies including Intel, Hewlett Packard Laboratory (USA), Cisco Systems (USA), Audacy (USA), Cochlear, Optus, ResMed and Katherine-Werke (Germany). He is an Associate Editor of IEEE Transactions on Antennas Propagation as well as IEEE Access.
Karu’s research activities are posted in the web at http://web.science.mq.edu.au/~esselle/ .
Time-Based Smart Sensory Systems
The seminal book of James Clerk Maxwell, “A Treatise on Electricity and Magnetism”, first published in 1873, described how to emulate a resistor by using one capacitor and a set of switches controlled by a clock signal. This way, the resistance value happens to be directly proportional to the period of the clock, and inversely proportional to the capacitance. Roughly one century later, in the 1980s, this idea was a keystone for the accurate and robust implementation of miniaturized, sophisticated systems using micro-electronic circuits and technologies. Actually, this Maxwell´s idea underlies the operation of high-fidelity audio reproduction systems, high-speed wireline communication modems, high-resilience automotive sensors, and high-resolution image sensors, among many other ITC wonders.
The main asset of Maxwell´s idea emerges when one comes to the implementation of systems described by differential equations, as it is the case for most front-ends of modern micro-electronic systems. The operation of these systems as signal processors is controlled by time constants, which are primarily defined by the products of resistances and capacitances values. Because resistors and capacitors are fabricated using uncorrelated processes, RC products are subjected to large errors. However, if resistors are replaced by switched-capacitors, following Maxwell´s idea, time constant values happen to be proportional to time, specifically to the period of a clock signal, and can hence be easily and accurately tuned. The precise implementation of dynamic equations is enabled this way. Also, systems based on capacitive-emulated resistors are more linear and more compact than other technological alternatives based on purely resistive v-i conversion.
This is just one example of many cases where the time variable is employed in smart sensory systems. For instance, time-coding, i.e. the representation of the information through time-related events, is today´s employed to address challenges emerging due to the reduction of the dynamic range in deep-submicron micro-technologies. Also, time-coding is extensively employed by natural, information-processing systems; and these systems have evolved for some 4billion years to develop extremely fast and energy-efficient sensory processing abilities. Furthermore, unveiling the intricate secrets of physics calls for systems capable to resolve events happening in the range of few psecs.
This lecture overviews some basic concepts, methods and applications related to the generation, control and applications of time in micro-electronic systems. Whenever possible and convenient, examples corresponding to accomplishments made by the research group of the lecturer will be used for illustration purposes.
(IEEE Fellow, 1999) received the Ph.D. degree in Physics-Electronics (Universidad de Sevilla, 1982) with several awards, including the IEEE Rogelio Segovia Torres Award (1981). After stays in University of California-Berkeley and Texas A&M University he became a Full Professor of Electronics at the University of Sevilla in 1995.
He co-founded the Instituto de Microelectrónica de Sevilla, a joint undertaken of Consejo Superior de Investigaciones Científicas (CSIC) and Universidad de Sevilla, and started a Lab on Analog and Mixed-Signal Circuits for Sensors and Communications.
In 2001, he was the main promotor of AnaFocus Ltd. and served it as CEO until June 2009, when the company reached maturity as a worldwide provider of smart CMOS imagers. He also participated in the foundation of the Hungarian start-up AnaLogic Ltd. He has nine patents filed; AnaFocus was founded on the basis of his patents on vision chip architectures. He was recipient of the 1st Technology Transfer award of the University of Sevilla.
His R&D production includes three generation of vision chips, analog front-ends for XDSL MoDems, ADCs for wireless communications, ADCs for automotive sensors, complete MoDems for power-line communications, among many other mixed-signal SoCs. Many of these chips were state-of-the-art in their respective fields. Some of them entered massive production. He also produced teaching materials on data converters that were delivered to companies and got the Quality Label of EuroPractice.
He has served and is currently serving as Editor, Associate Editor and Guest Editor for different IEEE and non-IEEE journals; he is in the committee of many international journals and conferences; and has chaired different international IEEE and SPIE conferences. Among others he has served as: TPC chair of IEEE ESSCIRC 1992 and 2010; General Chair of IEEE NDES 1996, IEEE CNNA 1996, IEEE ECCTD 2007 and IEEE ESSDERC-ESSCIRC 2010 and IEEE ICECS 2012. He served as VP Region 8 of IEEE CASS (2009-2012) and as Chair of the IEEE CASS Fellow Evaluation Committee (2010, 2012, 2013, 2014, and 2015). He has been appointed General Chairman of IEEE ISCAS 2020.
His publications have some 9,500 citations and several awards: the IEEE Guillemin-Cauer Best Paper Award, two Wiley’s IJCTA Best Paper Awards, two IEEE ECCTD Best Paper Awards, one IEEE-ISCAS Best Paper Award, one SPIE-IST Electronic Imaging Best Paper Award, the IEEE ISCAS Best Demo-Paper Award, and the IEEE ICECS Best Demo-Paper Award. He has been awarded the 2019 Mac Van Valkenburg award of IEEE-CASS and has been elected member of the Academia Europaea since 2019.