EPIC - Energy Processing and Integrated Circuits
Total activity: 1008
Type
Research group
Type of group
UPC research group
Acronym
EPIC
URL
http://www.eel.upc.edu/investigacion/grupos-de-investigacion-1/electronica-industrial-y-de-pontencia/epic-energy-processing-and-integrated-circuits?set_language=es Open in new window
Objectives
- Modelling, design (voltage and current modes), implementation and characterisation of analogue integrated circuits such as amplifiers, oscillators, automatically-tuned filters, communication circuits, etc.
- Modelling, design, control (linear control, current-mode control, sliding-mode control and fuzzy control), implementation and characterisation of switching power converters. Application to DC-DC and DC-AC conversions and to the series-parallel connection of converters.
- Fuzzy modelling of nonlinear dynamic systems.
- Microelectronic design of neuro-fuzzy processors and switching power converter controllers.
Keywords
convertidors de potencia conmutats,disseny VLSI,Disseny VLSI analògic en mode de corrent,modelat no lineal i control,processat fuzzy.,sintonia on-chip

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1 to 50 of 1008 results
  • Observation of chaotic behavior in automatic tuning loops for continuous-time filters

     Martínez García, Herminio; Cosp Vilella, Jordi; Manzanares Brotons, Manuel
    IEEE International Midwest Symposium on Circuits and Systems
    p. 742-745
    DOI: 10.1109/MWSCAS.2013.6674756
    Presentation's date: 2014-08
    Presentation of work at congresses

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    he appropriate linear dynamic modeling of continuous-time filters (CTFs) with automatic tuning loops should be obtained to assure stability in case an improved design of the loop controllers is to be carried out. With this aim, starting from a general and systematic analysis in order to obtain an equivalent small-signal linearized incremental model, from which transfer functions between output variables and control voltages are derived, the subsequent design of compensated loops with enhanced stability and dynamic performance is required. This systematic procedure allows obtaining improved controllers for the two involved control loops. However, CTFs with automatic tuning loops are nonlinear feedback systems with potential instability. What is more, nonlinear phenomena, which cannot be predicted by a design-oriented small signal modeling approach, are observed in this kind of tuning systems. The purpose of this work is to highlight that when control parameters are varied, the system could present different kinds of dynamical nonlinear phenomena such as bifurcations and chaotic behavior, which cannot be predicted by the small signal design-oriented model.

  • Optimization of WPT efficiency using a conjugate load in non-impedance matched systems.

     Chabalko, Matthew; Alarcon Cot, Eduardo Jose; Bou Balust, Elisenda; Ricketts, David S.
    IEEE International Symposium on Antennas and Propagation
    p. 645-646
    DOI: 10.1109/APS.2014.6904653
    Presentation's date: 2014-07-06
    Presentation of work at congresses

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    Maximum power transfer and maximum efficiency are two important design constraints in wireless power transfer applications. Several works have investigated the proper load and impedance match conditions to optimize either efficiency or power transfer. In this paper we show that the optimal load for maximum power transfer and maximum efficiency is the same (a conjugate matched load) when the source resistance is zero. This is important, as many WPT systems have a relatively low, unknown source impedance. Since the optimal load for both efficiency and power is the same as the source impedance approaches zero, the designer can use a bi-conjugate load for a near optimal design for both maximum power and efficiency. As the source impedance becomes significant, the bi-conjugate matched system provides higher power, but at the expense of lower efficiency. Maximum efficiency is achieved with a non-bi-conjugate load, when the source impedance is non-negligible.

  • De la teoría a la práctica: cinco años después de la integración de la competencia genérica de sostenibilidad en el Grado en Ingeniería Informática  Open access

     Garcia Almiñana, Jordi; Sanchez Carracedo, Fermin; Lopez Alvarez, David; Vidal Lopez, Eva Maria; Cabre Garcia, Jose Maria; García García, Helena; Alier Forment, Marc
    Jornadas de Enseñanza Universitaria de la Informática
    p. 253-260
    Presentation's date: 2014-07-09
    Presentation of work at congresses

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    La sostenibilidad es una de las competencias trans- versales básicas que todo ingeniero debería adquirir durante su formación. De hecho, seguir desarrollando ciencia y tecnología de espaldas a la sostenibilidad provocaría en poco tiempo un colapso de nuestro planeta. La puesta en marcha del Espacio Europeo de Educación Superior (EEES) ha propiciado una opor- tunidad única para replantearse diferentes aspectos educativos, entre los cuales destaca la inclusión de esta competencia en los planes de estudio. Existe literatura abundante sobre estrategias y pro- puestas teóricas para incluir esta competencia en las ingenierías. Sin embargo, pocos trabajos han sido llevados a cabo desde una perspectiva más práctica. La Facultat de Informàtica de Barcelona (FIB) posee amplia experiencia en el diseño de titulaciones adap- tadas al EEES y ha integrado la sostenibilidad en su plan de estudios de Grado en Ingeniería Informática. En este trabajo se revisa el proceso de diseño del plan de estudios de Grado en Ingeniería Informática de la FIB, aprobado en el año 2009, y se analiza la experiencia de integración de la sostenibilidad tras cinco años de funcionamiento del grado. Se comentan los mecanismos de organización y coordinación entre las asignaturas implicadas y, finalmente, se extraen las lecciones aprendidas.

    La sostenibilidad es una de las competencias transversales básicas que todo ingeniero debería adquirir durante su formación. De hecho, seguir desarrollando ciencia y tecnología de espaldas a la sostenibilidad provocaría en poco tiempo un colapso de nuestro planeta. La puesta en marcha del Espacio Europeo de Educación Superior (EEES) ha propiciado una oportunidad única para replantearse diferentes aspectos educativos, entre los cuales destaca la inclusión de esta competencia en los planes de estudio. Existe literatura abundante sobre estrategias y propuestas teóricas para incluir esta competencia en las ingenierías. Sin embargo, pocos trabajos han sido llevados a cabo desde una perspectiva más práctica. La Facultat de Informàtica de Barcelona (FIB) posee amplia experiencia en el diseño de titulaciones adaptadas al EEES y ha integrado la sostenibilidad en su plan de estudios de Grado en Ingeniería Informática. En este trabajo se revisa el proceso de diseño del plan de estudios de Grado en Ingeniería Informática de la FIB, aprobado en el año 2009, y se analiza la experiencia de integración de la sostenibilidad tras cinco años de funcionamiento del grado. Se comentan los mecanismos de organización y coordinación entre las asignaturas implicadas y, finalmente, se extraen las lecciones aprendidas.

    SUMMARY -- Sustainability is one of the basic professional skills that every engineer should incorporate during their training. In fact, developing science and technology without sustainability criteria would collapse our planet. The launching of the European Higher Education Area (EHEA) has provided a unique opportunity to rethink different educational aspects, including the integration of this skill into the curriculum. Abundant literature exists on strategies and theoretical proposals to include this skill into engineering. However, few studies have been done from a more practical perspective. The Barcelona School of Informatics (FIB) has wide experience in the design of degrees according to the EHEA, and has integrated sustainability into the Informatics Engineering degree. This paper reviews the process of the design of the FIB’s Informatics Engineering degree curriculum, approved in 2009, and analyses the experience of sustainability integration after five years. The organizational and coordination mechanisms between the subjects are discussed, and finally the lessons learnt are extracted.

  • Advances in non-radiative resonant inductive coupling wireless power transfer: a comparison of alternative circuit and system models driven by emergent applications

     Bou Balust, Elisenda; Sedwick, Raymond; Hu, Patrick; Alarcon Cot, Eduardo Jose
    IEEE International Symposium on Circuits and Systems
    p. 2037-2040
    DOI: 10.1109/ISCAS.2014.6865565
    Presentation's date: 2014-06-01
    Presentation of work at congresses

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    Recent research in wireless power transfer (WPT) using resonant inductive coupling has demonstrated very high efficiencies at large distances compared to the transmitting element dimensions, thereby increasing the number of potential applications of WPT. Since resonant inductive coupling is a very multidisciplinary field of research, different approaches have been proposed to predict the behaviour of these systems from the physical theory of resonators (coupled-mode theory) and circuit theory. Although the equivalence of these models for a point-to-point link has already been studied together with the performance metrics Power Transferred to the Load (PTL) and Power Transfer Efficiency (PTE), the new challenges and applications of this technology emphasize the necessity of analytical models to predict and assess the behavior of Multiple Input - Multiple Output (MIMO) links. In this article we revisit the current analytical models from the MIMO perspective, derive the analytical equations for the equivalent performance metrics PTE and PTL and demonstrate how to maximize them in a non-radiative resonant wireless power transfer link from a circuit-centric point of view, providing design guidelines in terms of optimal source and load impedances. This work concludes with a prospective discussion on open challenges of WPT. © 2014 IEEE.

  • Unveiling nonlinear dynamics in resonant inductively coupled wireless power transfer

     Bou Balust, Elisenda; El Aroudi, Abdelali; Fisher, Peter; Alarcon Cot, Eduardo Jose
    IEEE International Symposium on Circuits and Systems
    p. 2612-2615
    DOI: 10.1109/ISCAS.2014.6865708
    Presentation's date: 2014-06-01
    Presentation of work at congresses

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    Coupled magnetic resonance is considered to be a key enabling technology for mid-range wireless power transfer. Models and systems have hitherto considered linear resonators as underlying dynamics, thereby limiting practical deployability due to the extreme sensitivity in front of parameter mismatch and resonance detuning. In this work, structural nonlinear modeling of constituent elements of the resonant link-resonant coils- is considered to unveil the existence of nonlinear dynamic regimes. The methodology considered to explore the nonlinear behavior is based on a behavioral model consisting of state equations, Floquet theory and Filippov method to study the stability of the periodic regime through the associated monodromy matrix. The ultimate aim of the investigation is a design-oriented parameter space exploration which characterizes the border of occurrence of the different dynamic modes in wireless power transfer links. © 2014 IEEE.

  • Circuit area optimization in energy temporal sparse scenarios for multiple harvester powered systems

     Gomez Cid-fuentes, Raul; Cabellos Aparicio, Alberto; Alarcon Cot, Eduardo Jose
    IEEE International Symposium on Circuits and Systems
    p. 2486-2489
    DOI: 10.1109/ISCAS.2014.6865677
    Presentation's date: 2014-06-01
    Presentation of work at congresses

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    Multi-source energy harvesters are gaining interest as a robust alternative to power wireless sensors, since the sensor node can maintain its operation regardless of the fact that one of its energy sources might be temporarily unavailable. Interestingly, and less explored, when the energy availability of the energy sources present large temporal variations, combining multiple energy sources reduce the overall sparsity. As a result, the performance of a multiple energy harvester powered sensor node is significantly better compared to a single energy source which harvests the same amount of energy. In this context, a circuit area optimization framework for multiple source energy harvesting powered systems is proposed. This framework takes advantage of this improvement in performance to provide the optimal amount of energy harvesters, the requirements of each energy harvester and the required energy buffer capacity, such that the overall area or volume is minimized. As the results show, by conducting a joint design of the energy harvesters and the energy buffer, the overall area or volume of a sensor node can be significantly reduced. © 2014 IEEE.

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    Gestión de energía en sistemas híbridos Red-PV-diesel en el proyecto MED-Solar  Open access

     Velasco Quesada, Guillermo; Casellas Beneyto, Francisco; Guinjoan Gispert, Francisco; Pique Lopez, Robert; Martínez García, Herminio; Pineau, A.; Graillot, A.
    Seminario Anual de Automática, Electrónica Industrial e Instrumentación
    p. 3010.1-3010.6
    Presentation's date: 2014-06-26
    Presentation of work at congresses

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    El presente trabajo aborda el diseño de la estructura de un sistema de gestión de energía eléctrica aplicable a sistemas eléctricos híbridos formados por la red eléctrica y sistemas de generación fotovoltaica, generación diésel y almacenamiento. La implementación de estos sistemas híbridos y sus sistemas de gestión será, dentro del marco del Proyecto MED-Solar, en tres países del área del Máshrek (Líbano, Palestina y Jordania), con el fin de demostrar que este tipo de instalaciones puede reducir parte de la problemática energética presente en estos países y, por tanto, mostrarse atractiva para diversos sectores económicos.

  • Banco de pruebas para verificar el rendimiento estático y dinámico del MPPT

     Velasco Quesada, Guillermo; Casellas Beneyto, Francisco; Guinjoan Gispert, Francisco; Pique Lopez, Robert
    Seminario Anual de Automática, Electrónica Industrial e Instrumentación
    p. 3016.1-3016.6
    DOI: -
    Presentation's date: 2014-06-26
    Presentation of work at congresses

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  • Simulación mediante ¿hardware in the loop¿ de un convertidor buck

     Velasco Quesada, Guillermo; Casellas Beneyto, Francisco; Guinjoan Gispert, Francisco; Esteban, Jordi; Martínez García, Herminio; Pique Lopez, Robert
    Seminario Anual de Automática, Electrónica Industrial e Instrumentación
    p. 6007.1-6007.5
    Presentation's date: 2014-06-26
    Presentation of work at congresses

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  • Fuzzy logic controller design for battery energy management in a grid connected electro-thermal microgrid

     Arcos Aviles, Diego Gustavo; Vega Muñoz, Christian; Guinjoan Gispert, Francisco; Marroyo Palomo, Luis; Sanchis Gúrpide, Pablo
    IEEE International Symposium on Industrial Electronics
    p. 2014-2019
    DOI: 10.1109/ISIE.2014.6864926
    Presentation's date: 2014-06-01
    Presentation of work at congresses

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    A fuzzy logic controller strategy for battery energy management in a grid connected electro-thermal residential microgrid is presented. The fuzzy control policy manages the power of the microgrid storage elements in order to minimize a set of quality indices involving, among others, the power profile exchanged with the mains. Numerical simulations using real measured data generation and consumption are provided to both validate the control design and to highlight the benefits of including thermal elements in the overall energy management strategy of the system. © 2014 IEEE.

  • Nonlinear dynamics of an ambient noise driven array of coupled graphene nanostructured devices for energy harvesting

     El Aroudi, Abdelali; Lopez Suarez, Miquel; Alarcon Cot, Eduardo Jose; Rurali, Riccardo; Abadal, Gabriel
    International Conference on Structural Dynamics and Diagnosis
    p. 01001-1-01001-4
    DOI: 10.1051/matecconf/20141601001
    Presentation's date: 2014-05
    Presentation of work at congresses

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    Nonlinearities have been shown to play an important role in increasing the extracted energy of energy harvesting devices at the macro and micro scales. Vibration-based energy harvesting on the nano scale has also received attention. In this paper, we characterize the nonlinear dynamical behavior of an array of three coupled strained nanostructured graphene for its potential use in energy harvesting applications. The array is formed by three compressed vibrating membrane graphene sheet subject to external vibrational noise excitation. We present the continuous time dynamical model of the system in the form of a double-well three degree of freedom system. Random vibrations are considered as the main ambient energy source for the system and its performances in terms of the probability density function, RMS or amplitude value of the position, FFT spectra and state plane trajectories are presented in the steady state non-equilibrium regime when the noise level is considered as a control parameter.

  • Nonlinear dynamics and bifurcation behavior of a 2-DOF spring resonator with end stopper for energy harvesting

     El Aroudi, Abdelali; Blokhina, Elena; O'Connell, D.; Fu, B; Frizzell, R; Feely, Orla; Alarcon Cot, Eduardo Jose
    International Conference on Structural Dynamics and Diagnosis
    p. 08006-1-08006-6
    DOI: 10.1051/matecconf/20141608006
    Presentation's date: 2014-05
    Presentation of work at congresses

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    In this paper, the model of a two-degree-of-freedom (2-DOF) spring resonator with end stopper for an energy harvesting application is presented. Then we characterize its nonlinear dynamical behavior by numerical simulations when some suitable parameters are varied. The system is formed by two resonators subject to external vibrational excitation and with an end stopper. We present the continuous time dynamical model of the system in the form of a switched fourth order differential equation. Harmonic vibrations are considered as the main ambient energy source for the system and its frequency response representing the RMS value of the displacement is first computed. The dynamical behavior is unveiled by computing state-space trajectories, timedomain series and FFT spectra and frequency response as the excitation amplitude is varied.

  • Low cost photovoltaic array emulator design for the test of PV grid-connected inverters

     Chavarria Roe, Javier; Biel Sole, Domingo; Guinjoan Gispert, Francisco; Poveda Lopez, Alberto; Masana Nadal, Francisco; Alarcon Cot, Eduardo Jose
    International Multi-Conference on Systems, Signals and Devices
    p. 1-6
    DOI: 10.1109/SSD.2014.6808860
    Presentation's date: 2014-02-11
    Presentation of work at congresses

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    This paper presents a low cost photovoltaic array emulator design based on a DC-DC Boost converter. This design arises from the need to study in the laboratory new PV inverters based on SiC devices in order to improve their performances. The lack of space for installation of real photovoltaic panels and the high costs of the commercial emulators require of alternative systems which allow the reproduction of the characteristic curves of the panels as well as their dependence on changing environmental conditions. The emulator design is applied to a full-bridge single phase grid-connected inverter. Simulation results are provided to confirm the proper operation of the PV emulator. © 2014 IEEE.

  • Performance analysis of dual-frequency buck converter for integrated power management

     Shirmohammadli, V.; Saberkari, Alireza; Alarcon Cot, Eduardo Jose
    Power Electronics, Drive Systems and Technologies Conference
    p. 402-407
    DOI: 10.1109/PEDSTC.2014.6799409
    Presentation's date: 2014-02
    Presentation of work at congresses

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    The use of dual-frequency (DF) buck converter architecture consisting of a merged structure of high and low frequency buck cells is presented as a candidate topology for integrated power management to obtain favorable tradeoffs in terms of efficiency, switching ripple, and bandwidth. It is shown that having two degrees of freedom in designing the DF buck helps to achieve high efficiency and low output ripples, simultaneously. A comparison analysis is done with regards to the aforementioned performance indexes with the standard and three-level buck converters and the results are validated in HSPICE in a 0.35 µm CMOS process.

  • Class E2 resonant non-radiative wireless power transfer link: a design-oriented joint circuit-system co-characterization approach

     Bou Balust, Elisenda; Nagashima, Tomoharu; Sekiya, Hiroo; Alarcon Cot, Eduardo Jose
    International Multi-Conference on Systems, Signals and Devices
    p. 1-4
    DOI: 10.1109/SSD.2014.6808902
    Presentation's date: 2014-02-11
    Presentation of work at congresses

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    Resonant Inductive CouplingWireless Power Transfer is a key technology to provide an efficient and harmless wireless energy channel to consumer electronics, biomedical implants and wireless sensor networks. Many applications have been proposed for this technology, but the interplay between the Resonant Inductive Coupling magnetic link and the power electronics front-end is still unclear. In this paper, we propose a design-oriented joint circuit-system approach to design a high-efficiency resonant inductive coupling wireless power transfer link embedded in a class E2 DC-DC converter. © 2014 IEEE.

  • Transferencia de energía inalámbrica: acoplamiento inductivo resonante

     Poveda López, Alberto; Vidal Lopez, Eva Maria; Martínez García, Herminio; Alarcon Cot, Eduardo Jose
    Competitive project

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  • On the Scalability Limits of Communication Networks to the Nanoscale  Open access

     Llatser Marti, Ignacio
    Universitat Politècnica de Catalunya
    Theses

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    Los nanosistemas, sistemas integrados con un tamaño total de unos pocos micrómetros, son capaces de interactuar en la nanoescala, pero su corto radio de acción limita su utilidad en escenarios prácticos. Las nanoredes, que surgen de la interconexión de nanosistemas, amplían su ámbito de operación permitiendo la comunicación entre nanosistemas, aumentando de esta forma sus aplicaciones potenciales. Con el fin de dotar de capacidades de comunicación a los nanosistemas, su subsistema de comunicación debe reducirse a unos pocos micrómetros. Existen dudas sobre la viabilidad de miniaturizar las antenas metálicas actuales a un tamaño tan pequeño, especialmente porque su frecuencia de resonancia sería extremadamente alta (en el espectro óptico), lo que causaría a una gran atenuación de las ondas radiadas. Como alternativa, se han propuesto dos nuevos paradigmas para implementar comunicaciones inalámbricas entre nanosistemas: las comunicaciones moleculares y las comunicaciones inalámbricas basadas en grafeno. Por un lado, las comunicaciones moleculares consisten en el intercambio de moléculas entre nanosistemas, inspirado en la comunicación entre células vivas. En las comunicaciones moleculares basadas en difusión (DMC), las moléculas emitidas se propagan por el medio mediante un proceso de difusión hasta que alcanzan el receptor. Por otro lado, el grafeno (una lámina de átomos de carbono de un átomo de espesor) permite implementar antenas de grafeno plasmónicas, o grafenas. Debido a efectos plasmónicos, grafenas con un tamaño de unos pocos micrómetros radian ondas en la banda de terahercios, dando lugar al paradigma de las comunicaciones inalámbricas basadas en grafeno (GWC). Para averiguar cómo escalan las redes de comunicación a medida que se reducen sus dimensiones, esta tesis se presenta un análisis de la escalabilidad de las redes de comunicaciones hacia la nanoescala, siguiendo un modelo general con la menor cantidad posible de hipótesis. Hemos propuesto dos esquemas de detección en DMC: detección de amplitud y detección de energía. Hemos identificado importantes métricas de rendimiento y calculado su escalabilidad con respecto a la distancia de transmisión, que difiere significativamente respecto a las comunicaciones inalámbricas tradicionales. Estas nuevas tendencias de escala requieren el diseño de nuevos protocolos de red especialmente adaptados a las redes de DMC. El análisis de la propagación de ondas plasmónicas en grafenas permite determinar sus propiedades de radiación. En particular, la frecuencia de resonancia de las grafenas no sólo es más baja que en antenas metálicas, sino que también aumenta más lentamente a medida que reducimos su longitud. Por otra parte, la frecuencia de resonancia de las grafenas puede ser ampliamente controlada en función de parámetros como las dimensiones de la grafena, el tiempo de relajación del grafeno y el potencial químico. Además, proponemos un montaje experimental que permite la medición de grafenas alimentadas con una fuente fotoconductora. También hemos analizado los efectos de la absorción molecular en el canal de terahercios a corto alcance, el escenario de operación de las grafenas. La absorción molecular es un proceso por el cual moléculas presentes en la atmósfera absorben parte de la energía de las ondas radiadas por las grafenas, degradando su rendimiento. Hemos cuantificado esta degradación derivando parámetros de rendimiento en este escenario, que muestran novedosas tendencias de escalabilidad en función de la distancia de transmisión. Por último, hemos encontrado que la capacidad de canal de GWC escala mejor a medida que el tamaño de la antena se reduce con respecto a las comunicaciones inalámbricas tradicionales. En consecuencia, las GWC requerirán una potencia de transmisión más baja para lograr un cierto rendimiento. Estos resultados establecen un marco general que puede servir de guía para diseñar las futuras redes de comunicaciones inalámbricas entre nanosistemas.

    Nanosystems, integrated systems with a total size of a few micrometers, are capable of interacting at the nanoscale, but their short operating range limits their usefulness in practical macro-scale scenarios. Nanonetworks, the interconnection of nanosystems, will extend their range of operation by allowing communication among nanosystems, thereby greatly enhancing their potential applications. In order to integrate communication capabilities into nanosystems, their communication subsystem needs to shrink to a size of a few micrometers. There are doubts about the feasibility of scaling down current metallic antennas to such a small size, mainly because their resonant frequency would be extremely high (in the optical domain) leading to a large free-space attenuation of the radiated EM waves. In consequence, as an alternative to implement wireless communications among nanosystems, two novel paradigms have emerged: molecular communication and graphene-enabled wireless communications. On the one hand, molecular communication is based on the exchange of molecules among nanosystems, inspired by communication among living cells. In Diffusion-based Molecular Communication (DMC), the emitted molecules propagate throughout the environment following a diffusion process until they reach the receiver. On the other hand, graphene, a one-atom-thick sheet of carbon atoms, has been proposed to implement graphene plasmonic RF antennas, or graphennas. Graphennas with a size in the order of a few micrometers show plasmonic effects which allow them to radiate EM waves in the terahertz band. Graphennas are the enabling technology of Graphene-enabled Wireless Communications (GWC). In order to answer the question of how communication networks will scale when their size shrinks, this thesis presents a scalability analysis of the performance metrics of communication networks to the nanoscale, following a general model with as few assumptions as possible. In the case of DMC, two detection schemes are proposed: amplitude detection and energy detection. Key performance metrics are identified and their scalability with respect to the transmission distance is found to differ significantly from the case of traditional wireless communications. These unique scaling trends present novel challenges which require the design of novel networking protocols specially adapted to DMC networks. The analysis of the propagation of plasmonic waves in graphennas allows determining their radiation performance. In particular, the resonant frequency of graphennas is not only lower than in metallic antennas, but it also increases more slowly as their length is reduced to the nanoscale. Moreover, the study of parameters such as the graphenna dimensions, the relaxation time of graphene and the applied chemical potential shows the tunability of graphennas in a wide frequency range. Furthermore, an experimental setup to measure graphennas based on feeding them by means of a photoconductive source is described. The effects of molecular absorption in the short-range terahertz channel, which corresponds to the expected operating scenario of graphennas, are analyzed. Molecular absorption is a process in which molecules present in the atmosphere absorb part of the energy of the terahertz EM waves radiated by graphennas, causing impairments in the performance of GWC. The study of molecular absorption allows quantifying this loss by deriving relevant performance metrics in this scenario, which show novel scalability trends as a function of the transmission distance with respect to the case of free-space propagation. Finally, the channel capacity of GWC is found to scale better as the antenna size is reduced than in traditional wireless communications. In consequence, GWC will require lower transmission power to achieve a given performance target. These results establish a general framework which may serve designers as a guide to implement wireless communication networks among nanosystems.

  • Premi al Millor Projecte de Final de Carrera CETIB 2013

     Martínez García, Herminio
    Award or recognition

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    Design of an on-chip linear-assisted DC-DC voltage regulator  Open access

     Cosp Vilella, Jordi; Martínez García, Herminio
    IEEE International Conference on Electronics, Circuits and Systems
    p. 353-356
    Presentation's date: 2013-12-10
    Presentation of work at congresses

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    This article shows the design of an on-chip CMOS linear-assisted DC-DC regulator. It results a good alternative topology to classic switching DC-DC power converters. In the presented technique, an auxiliary linear regulator is used to cancel the output voltage ripple and provides fast responses for load and line variations. On the other hand, a switching converter, connected in parallel, allows supplying almost the whole output current demanded by the load. The objective of this linear-assisted regulator or hybrid topology is to achieve a high efficiency of switching converters, with suitable load and line regulation features, typical of linear regulators. In this kind of on-chip applications, CMOS is the current prevailing technology. Thus, in order to implement on-chip power supply systems and on-chip power management systems with low-to-medium current consumption, this structure has good features.

    Postprint (author’s final draft)

  • IEEE Journal on Photovoltaics

     Pique Lopez, Robert
    Collaboration in journals

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  • Design of a 4.5-V, 450-mA low-dropout voltage linear regulator based on a cascoded OTA

     Martínez García, Herminio; Grau Saldes, Antoni; Bolea Monte, Yolanda
    Annual Conference of the IEEE Industrial Electronics Society
    p. 2242-2247
    Presentation's date: 2013-11-13
    Presentation of work at congresses

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    This article aims to present the design of a 4.5-V 450-mA low drop-out (LDO) voltage linear regulator based on a two-stage cascoded operational transconductance amplifier (OTA) as error amplifier. The aforementioned two-stage OTA is designed with cascoded current mirroring technique to boost up the output impedance. The proposed OTA has a DC gain of 101 dB under no load condition. The designed reference voltage included in the LDO regulator is provided by a band gap reference with the temperature coefficient (T¿) of 0.025 mV/ºC. The proposed LDO regulator has a maximum drop-out voltage of 0.5 V @ 450 mA of load current, and has the worst case power supply rejection ratio (PSRR) of [54.5 dB, 34.3 dB] @ [100 Hz, 10 kHz] in full load condition. All the proposed circuits are designed using a 0.35 µm CMOS technology. The design is checked in order to corroborate its performance for wide range of input voltage, founding that the circuit design works fine meeting all the initial specification requirements.

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    On-chip SIDO buck converter with independent outputs  Open access

     Martínez García, Herminio; Eachempatti, Haritha; Silva-Martínez, José
    Conference on Design of Circuits and Integrated Systems
    p. 654-657
    Presentation's date: 2013-11-27
    Presentation of work at congresses

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    The portable electronics market is rapidly migrating towards more compact devices requiring multiple high-integrity high-efficiency voltage supplies for empowering the systems. This paper demonstrates a single inductor used in a buck converter with two output voltages from an input battery with voltage of value 3 V. The main targets are low cross regulation between the two outputs to supply independent load current levels while maintaining desired output voltage values well within the acceptable ripple levels. The proposed controller provides adaptive levels in order to limit the output ripple, achieving a high output voltage accuracy. A reverse current detector to avoid negative current flowing through the inductor, prevents possible efficiency degradation.

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    `Bang-Bang¿ technique in supply modulation for linear wideband RF power amplifiers  Open access

     Martínez García, Herminio; Turkson, Richard; Silva-Martínez, José
    Conference on Design of Circuits and Integrated Systems
    p. 16-19
    Presentation's date: 2013-11-27
    Presentation of work at congresses

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    This paper deals with the design techniques of power efficient switching regulators intended for linear power amplifiers employing envelope tracking techniques in wideband wireless standards. The bottlenecks involve a tradeoff between ripple voltage, slew rate and bandwidth. The slew rate limitation is identified as the main challenge, then a `bang-bang¿ slew enhancement technique is proposed. This approach enables the use of efficient supply modulators in wideband power amplifiers. The proposed scheme does not significantly degrade PA efficiency and preserves the stability of the switching regulator. The prototype has been implemented using the TSMC 0.18 µm technology; schematic simulation results in Cadence® are presented to prove the concept.

    This paper deals with the design techniques of power efficient switching regulators intended for linear power amplifiers employing envelope tracking techniques in wideband wireless standards. The bottlenecks involve a tradeoff between ripple voltage, slew rate and bandwidth. The slew rate limitation is identified as the main challenge, then a ‘bang-bang’ slew enhancement technique is proposed. This approach enables the use of efficient supply modulators in wideband power amplifiers. The proposed scheme does not significantly degrade PA efficiency and preserves the stability of the switching regulator. The prototype has been implemented using the TSMC 0.18 µm technology; schematic simulation results in Cadence® are presented to prove the concept.

  • UPCSAT-1, demostrador CubeSat para observación terrestre

     Jove Casulleras, Roger; Camps Carmona, Adriano Jose; Vall-llossera Ferran, Mercedes Magdalena; Bou Balust, Elisenda; Ramos Castro, Juan Jose; Alarcon Cot, Eduardo Jose; Alonso Arroyo, Alberto
    Congreso de la Asociación Española de Teledetección
    p. 49-52
    Presentation's date: 2013-10
    Presentation of work at congresses

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    UPCSat-1, es el primer proyecto de la Universitat Politécnica de Catalunya para construir y lanzar un pico- satélite. El objetivo principal de este proyecto es construir, ensamblar, testear y poner en órbita baja terrestre (LEO) un sensor óptico y un sensor de oxígeno monoatómico entre otros demostradores tecnológicos. Empezado en 2007 y actualmente en fase de integración, el satélite UPCSat-1 pretende demostrar la validez de la plataforma y las tecnologías que incorpora. Su objetivo es adquirir el know-how para la fabricación de CubeSats para preparar misiones más complejas en un futuro cercano. Por otro lado el proyecto tiene un fuerte componente educacional puesto que algunos de los subsistemas han sido desarrollados por nuestros estudiantes a través de sus proyectos finales de carrera. Se espera el lanzamiento para antes de 2015.

  • 1st European award for best practices for the integration of Sustainable Human Development (SHD) into technology/engineering education

     Alier Forment, Marc; Cabre Garcia, Jose Maria; Franquesa Griso, David; Garcia Almiñana, Jordi; García García, Helena; Lopez Alvarez, David; Sanchez Carracedo, Fermin; Vidal Lopez, Eva Maria
    Award or recognition

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  • Engineering Education. REDU. Revista de Docencia Universitaria

     Pique Lopez, Robert
    Vol. 11, num. 2. Octubre 2013
    Collaboration in journals

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  • On chaotic behavior in automatic tuning loops for continuous-time filters

     Cosp Vilella, Jordi; Martínez García, Herminio
    European Conference on Circuit Theory and Design
    p. 1-4
    DOI: 10.1109/ECCTD.2013.6662232
    Presentation's date: 2013-09-10
    Presentation of work at congresses

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    Continuous-time filters (CTFs) with automatic tuning loops are nonlinear feedback systems with potential instability. Thus, their appropriate linear dynamic modeling should be obtained to assure stability in case of an improved design of the loop controllers is to be carried out. A systematic approach using a small signal model would allow obtaining these controllers. However, bifurcations and nonlinear phenomena may appear which cannot be predicted by this analysis. This leads to potential instability, semiperiodic or chaotic behavior and, thus, circuit malfunction. The aim of this paper is to show by means of simulations and experimental results that nonlinear phenomena, which cannot be predicted by the common small signal analysis, may appear in this kind of circuits when circuit parameters are varied.

    Continuous–time filters (CTFs) with automatic tuning loops are nonlinear feedback systems with potential instability. Thus, their appropriate linear dynamic modeling should be obtained to assure stability in case of an improved design of the loop controllers is to be carried out. A systematic approach using a small signal model would allow obtaining these controllers. However, bifurcations and nonlinear phenomena may appear which cannot be predicted by this analysis. This leads to potential instability, semiperiodic or chaotic behavior and, thus, circuit malfunction. The aim of this paper is to show by means of simulations and experimental results that nonlinear phenomena, which cannot be predicted by the common small signal analysis, may appear in this kind of circuits when circuit parameters are varied.

  • Inductively coupled wireless power transfer with Class-E2 DC-DC converter

     Nagashima, Tomoharu; Inoue, Kazuhide; Wei, Xiuqin; Bou, Elisenda; Alarcon Cot, Eduardo Jose; Sekiya, Hiroo
    European Conference on Circuit Theory and Design
    p. 1-4
    DOI: 10.1109/ECCTD.2013.6662278
    Presentation's date: 2013-09-08
    Presentation of work at congresses

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    This paper proposes an inductive coupled wireless power transfer (WPT) system with class-E2 dc-dc converter along with its design procedure. The proposed WPT system can achieve high power-conversion efficiency at high frequencies because it satisfies the class-E zero-voltage switching and zero-derivative-voltage switching conditions on both the inverter and the rectifier. By using the class-E inverter as a transmitter and the class-E rectifier as a receiver, high power-delivery efficiency can be achieved in the designed WPT system. By using a numerical design procedure proposed in the previous work, it is possible to design the WPT system without considering the impedance matching for satisfying the class-E ZVS/ZDS conditions. The experimental results of the design example showed the overall efficiency of 85:1%at 100Woutput power and 200 kHz operating frequency.

  • 8th Google Faculty Reserach Award

     Alarcon Cot, Eduardo Jose; Camps Carmona, Adriano Jose; Ramos Castro, Juan Jose
    Award or recognition

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  • Observation of chaotic behavior in automatic tuning loops for continuous¿time filters

     Martínez García, Herminio; Cosp Vilella, Jordi; Manzanares Brotons, Manuel
    IEEE International Midwest Symposium on Circuits and Systems
    p. 742-745
    Presentation's date: 2013-08-06
    Presentation of work at congresses

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    The appropriate linear dynamic modeling of continuous¿time filters (CTFs) with automatic tuning loops should be obtained to assure stability in case an improved design of the loop controllers is to be carried out. With this aim, starting from a general and systematic analysis in order to obtain an equivalent small¿signal linearized incremental model, from which transfer functions between output variables and control voltages are derived, the subsequent design of compensated loops with enhanced stability and dynamic performance is required. This systematic procedure allows obtaining improved controllers for the two involved control loops. However, CTFs with automatic tuning loops are nonlinear feedback systems with potential instability. What is more, nonlinear phenomena, which cannot be predicted by a design-oriented small signal modeling approach, are observed in this kind of tuning systems. The purpose of this work is to highlight that when control parameters are varied, the system could present different kinds of dynamical nonlinear phenomena such as bifurcations and chaotic behavior, which cannot be predicted by the small signal design-oriented model.

  • Magnetic characterization of interfering objects in resonant inductive coupling wireless power transfer

     Bou Balust, Elisenda; Vidal, D.; Sedwick, Raymond; Alarcon Cot, Eduardo Jose
    Progress in Electromagnetics Research Symposium
    p. 1554-1559
    Presentation's date: 2013-08-16
    Presentation of work at congresses

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    Resonant Inductive Coupling (RIC) Wireless Power Transfer is a key technology to provide an efficient and harmless wireless energy channel to consumer electronics, biomedical implants and wireless sensor networks. However, there are two factors that are limiting the applicability of this technology: the effects of distance variation between transmitter and receiver and the effects of interfering objects. While distance variation in WPT has been thoroughly studied, the effects of conductive interfering objects in resonant inductive coupling links are still unclear. When a conductive element is in the vicinity of a RIC link, both the transmitter and the receiver can experiment a change on their resonant frequencies as well as their impedances. This can greatly affect the effciency of such WPT link causing it to a) make the transmitter and/or receiver act as a pass-band filter and b) loose part of the transmitter magnetic field through coupling to the interfering object. Depending on the natural resonant frequency of the object and the distances between this object and the transmitter and receiver antennas, this can affect significantly the RIC wireless power transfer link. In this article, we characterize the Magnetic behavior of a resonant inductive coupled link in the presence of a conductive interfering object using a Finite Element Field Solver (FEKO). Several distances between interference and transmitter/receiver are analyzed providing a design space exploration and applicability study of this link.

  • Envelope tracking technique with bang-bang slew-rate enhancer for linear wideband RF PAs

     Turkson, Richard; Prakash, Suraj; Silva-Martínez, José; Martínez García, Herminio
    IEEE International Midwest Symposium on Circuits and Systems
    p. 629-632
    Presentation's date: 2013-08-06
    Presentation of work at congresses

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  • Technologies for electric current sensors

     Velasco Quesada, Guillermo; Conesa Roca, Alfonso; Roman Lumbreras, Manuel
    Date of publication: 2013-08-01
    Book chapter

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    Within the field of study of classical physics, we can find the branch concerned with electromagnetic phenomena: electromagnetism. Electromagnetism describes the interaction between electric charges through the concepts of electric and magnetic fields. The formulation of the electromagnetic theory principles has enabled the engineering sciences, such as electricity and electronics, to develop applications related to the treatment of energy and information using electric charges as physical support. Most operations performed on the processing of energy or information supported by electric charges involve the movement of these charges, and there are two basic electric magnitudes to represent this movement: electric voltage (also called potential difference or voltage) and electric current. Regardless the scope of the developed application, many electric or electronic systems need to measure the value of either of these two magnitudes. This chapter is devoted to reviewing the various techniques currently available to measure or sensing the electric current intensity.

  • Estudio y simulación de MOSFETs de carburo de silicio (SiC) mediante PSIM para un inversor fotovoltaico en puente completo conectado a red

     Chavarria Roe, Javier; Biel Sole, Domingo; Guinjoan Gispert, Francisco; Poveda Lopez, Alberto; Alarcon Cot, Eduardo Jose; Massana, Francisco
    Seminario Anual de Automática, Electrónica Industrial e Instrumentación
    p. 50
    Presentation's date: 2013-07-11
    Presentation of work at congresses

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    El presente artículo muestra, mediante simulación PSIM, el impacto de la utilización de MOSFETs de Carburo de Silicio (SiC) en la eficiencia de inversores fotovoltaicos en puente completo conectados a red. Las simulaciones presentadas utilizan la facilidad ¿Device Database Editor¿ para construir modelos de MOSFET tanto de Si como de SiC y comparan diversos parámetros como la eficiencia o el rizado de la corriente de salida. Estas simulaciones también permiten establecer un método de diseño de la frecuencia de conmutación y del inductor de salida del inversor.

  • La gestión de la calidad: algunas reflexiones sobre los procesos de calidad que se implantan en los centros docentes universitarios

     Perez Gracia, Maria de La Vega; Lopez Lopez, Jose; Buenestado Caballero, Pablo; Garcia-Alzórriz Pardo, Juan Antonio; Torres Camara, Ricardo; Martinez Sanchez, Joan; Velasco Quesada, Guillermo
    Congreso Universitario de Innovación Educativa en las Enseñanzas Técnicas (CUIEET)
    p. 117-124
    Presentation's date: 2013-07-12
    Presentation of work at congresses

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    Resumen. Tras diseñar un sistema interno de garantía de calidad se inició el proceso de implantación. Sin embargo, este proceso se ha dilatado en el tiempo y no se ha podido finalizar todavía. Es posible que muchos de los problemas con los que nos hemos encontrado sean fallos del sistema diseñado, que no fueron previstos por el centro ni detectados por los revisores externos. La discusión sobre nuestra experiencia, contrastándola con la de otros centros puede ser una herramienta valiosa para mejorar un sistema complejo. Abstract. After the quality system design, implementation was the second step. However, several difficulties caused the delay in the implementation process and the system is not yet finalized. It is possible that some of the problems in the process were due to a non appropriate design or evaluation of the quality system. In our opinion, the discussion about the experience, contrasted to the other centres¿ experiences could help in the improvement of the system.

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    Chaotic behaviour in on-chip automatic tuning loops for continuous-time filters  Open access

     Martínez García, Herminio; El Aroudi, Abdelali; Alarcon Cot, Eduardo Jose; Poveda Lopez, Alberto
    Seminario Anual de Automática, Electrónica Industrial e Instrumentación
    p. 1-4
    Presentation's date: 2013-07-11
    Presentation of work at congresses

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    Continuous-time filters (CTF) with automatic tuning loops are nonlinear feedback systems with potential instability. While an appropriate small signal linear dynamic modeling of the tunable filter should be obtained for design purpose, its ability to predict the real nonlinear dynamic behavior of the system is limited. In order to overcome this problem, a general and systematic procedure is used to obtain a large signal nonlinear model. The obtained model can accurately predict nonlinear phenomena such as bifurcations and chaotic behavior. From this model, some numerical simulations results are presented in this paper. As far as the authors know, the observation of these phenomena in CTF with tuning loops has not been previously presented. Thus, the results obtained in this work can provide some help to obtain improved controllers (with higher bandwidth and better performance) for the two involved control loops.

  • The use of power gyrator structures for energy processing in photovoltaic solar facilities

     Martínez García, Herminio; Grau Saldes, Antoni; Bolea Monte, Yolanda
    IEEE International Conference on Industrial Informatics
    p. 426-429
    Presentation's date: 2013-07-30
    Presentation of work at congresses

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    This paper provides a classification of high efficiency switching power-gyrator structures and their use as cells for energy processing in photovoltaic solar facilities. Having into account the properties of these topologies presented in the article, their inclusion in solar facilities allows increasing the performance of the whole installation. Thus, the design, simulation and implementation of a G-type power gyrator are carried out throughout the text. In addition, in order to obtain the maximum power from the photovoltaic solar panel, a maximum power point tracking (MPPT) is mandatory in the energy processing path. Therefore, the practical implementation carried out includes a control loop of the power gyrator in order to track the aforementioned maximum power point of the photovoltaic solar panel.

    This paper provides a classification of high efficiency switching power-gyrator structures and their use as cells for energy processing in photovoltaic solar facilities. Having into account the properties of these topologies presented in the article, their inclusion in solar facilities allows increasing the performance of the whole installation. Thus, the design,simulation and implementation of a G-type power gyrator are carried out throughout the text. In addition, in order to obtain the maximum power from the photovoltaic solar panel, a maximum power point tracking (MPPT) is mandatory in the energy processing path. Therefore, the practical implementation carried out includes a control loop of the power gyrator in order to track the aforementioned maximum power point of the photovoltaic solar panel.

  • Power gyrator structures and their use as cells for energy processing in photovoltaic solar facilities

     Martínez García, Herminio; Grau Saldes, Antoni; Bolea Monte, Yolanda; Gamiz Caro, Juan
    Spanish-Portuguese Conference on Electrical Engineering
    p. 1-5
    Presentation's date: 2013-07-04
    Presentation of work at congresses

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    This paper provides a classification of high efficiency switching power-gyrator structures and their use as cells for energy processing in photovoltaic solar facilities. Having into account the properties of these topologies presented in the article, their inclusion in solar facilities allows increasing the performance of the whole installation. Thus, the design, simulation and implementation of a G-type power gyrator are carried out throughout the text. In addition, in order to obtain the maximum power from the photovoltaic solar panel, a maximum power point tracking (MPPT) is mandatory in the energy processing path. Therefore, the practical implementation carried out includes a control loop of the power gyrator in order to track the aforementioned maximum power point of the photovoltaic solar panel.

  • Diseño de una plataforma docente para el estudio de los sistemas de recolección de energía (energy harvesting) en los grados de ingeniería

     Martínez García, Herminio
    Spanish-Portuguese Conference on Electrical Engineering
    p. 1-4
    Presentation's date: 2013-07-04
    Presentation of work at congresses

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    El presente artículo presenta el diseño e implementación física de una plataforma docente recolectora y acondicionadora de energía práctica para aplicaciones de energy harvesting. Concretamente, muestra la realización de un sistema de acondicionamiento de energía solar fotovoltaica a partir de un modelo concreto de panel solar. Con el fin de conseguir una plataforma lo más eficiente posible, se ha implementado un sistema de seguimiento del punto de máxima potencia (MPPT) del panel fotovoltaico que optimiza el rendimiento del mismo, adentrando, a su vez, al estudiante de Ingeniería en este tipo de algoritmos. Además, la plataforma recolectora posee regulación de salida, ofreciendo así una tensión de salida constante, independientemente tanto de variaciones de carga como de la tensión de entrada.

  • Supply modulator for linear wideband RF power amplifiers

     Turkson, Richard; Silva-Martínez, José; Martínez García, Herminio
    Seminario Anual de Automática, Electrónica Industrial e Instrumentación
    p. 1-4
    Presentation's date: 2013-07-11
    Presentation of work at congresses

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    This paper deals with the design techniques of power efficient switching regulators intended for linear power amplifiers employing envelope tracking techniques in wideband wireless standards. The bottlenecks involve a tradeoff between ripple voltage, slew rate and bandwidth. The slew rate limitation is identified as the main challenge, then a `bang-bang¿ slew-enhancement technique is proposed. This approach enables the use of efficient supply modulators in wideband power amplifiers. The proposed scheme does not significantly degrade PA efficiency and preserves the stability of the switching regulator. The prototype has been implemented using the TSMC 0.18 µm technology; schematic simulation results in Cadence ® are presented to prove the concept.

  • La sostenibilidad en los proyectos de ingeniería  Open access

     Cabre Garcia, Jose Maria; Garcia Almiñana, Jordi; García Gómez, Helena; Lopez Alvarez, David; Sanchez Carracedo, Fermin; Vidal Lopez, Eva Maria; Alier Forment, Marc
    Jornadas de Enseñanza Universitaria de la Informática
    p. 317-324
    DOI: 10.6035/e-TIiT.2013.13
    Presentation's date: 2013-07-12
    Presentation of work at congresses

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    El Trabajo de Fin de Grado representa la última prueba para que el estudiante de grado demuestre que está preparado para ejercer como ingeniero, elaborando y defendiendo un proyecto de envergadura. El proyecto debe cumplir todos los requisitos que se exigen a un proyecto de ingeniería, desde el análisis del problema hasta la presentación de una solución. Los autores del presente trabajo pensamos que todo proyecto de ingeniería debe incorporar un informe de sostenibilidad que demuestre que el proyecto es sostenible en los ámbitos social, ambiental y económico. Existe poca experiencia en este tema, tanto en la empresa como en la universidad, ya que las empresas (algunas) hace pocos años que han incorporado la sostenibilidad como uno de los criterios de realización de sus proyectos y las universidades apenas han comenzado a trabajar en esa dirección. En este trabajo se presentan algunas reflexiones sobre cómo debería ser tratada la sostenibilidad en un proyecto de ingeniería, y en particular cómo se pueden aplicar estas ideas al Trabajo de Fin de Grado.

    El Trabajo de Fin de Grado representa la última prueba para que el estudiante de grado demuestre que está preparado para ejercer como ingeniero, elaborando y defendiendo un proyecto de envergadura. El proyecto debe cumplir todos los requisitos que se exigen a un proyecto de ingeniería, desde el análisis del problema hasta la presentación de una solución. Los autores del presente trabajo pensamos que todo proyecto de ingeniería debe incorporar un informe de sostenibilidad que demuestre que el proyecto es sostenible en los ámbitos social, ambiental y económico. Existe poca experiencia en este tema, tanto en la empresa como en la universidad, ya que las empresas (algunas) hace pocos años que han incorporado la sostenibilidad como uno de los criterios de realización de sus proyectos y las universidades apenas han comenzado a trabajar en esa dirección. En este trabajo se presentan algunas reflexiones sobre cómo debería ser tratada la sostenibilidad en un proyecto de ingeniería, y en particular cómo se pueden aplicar estas ideas al Trabajo de Fin de Grado.

    SUMMARY -- The Final Degree Work represents the last test for the students to demonstrate they are ready to practice as engineer, developing and defending a major project. The project must meet all requirements demanded on an engineering project, from the problem analysis to the presentation of one solution. The authors of this paper believe that every engineering project must include a sustainability report which demonstrates that the project is sustainable in the social, environmental and economic scopes. There is little experience in this subject, either in enterprises or in universities, as only few companies have recently incorporated sustainability as one of their criteria for developing their projects, and the universities have hardly begun working in that direction. This paper presents some thoughts about how sustainability should be addressed in an engineering project and, in particular, how these ideas should be applied to the Final Degree Work.

  • SiC Power JFET Electrothermal Macromodel

     Massana, Francisco; Chavarria Roe, Javier; Biel Sole, Domingo; Poveda Lopez, Alberto; Guinjoan Gispert, Francisco
    International Conference Mixed Design of Integrated Circuits and Systems
    p. 444-447
    Presentation's date: 2013-06-21
    Presentation of work at congresses

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    Designing CDIO capstone projects: a systems thinking approach  Open access

     Alarcon Cot, Eduardo Jose; Bou Balust, Elisenda; Camps Carmona, Adriano Jose; Bragos Bardia, Ramon; Oliveras Verges, Albert; Pegueroles Valles, Josep Rafel; Sayrol Clols, Elisa; Marques Acosta, Fernando
    International CDIO Conference
    p. 1-9
    Presentation's date: 2013-06-10
    Presentation of work at congresses

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    Given the all-pervasiveness of Systems thinking -which consists of thinking about things as systems- as a way of reasoning, in this work we will describe its application to make an interpretation of how to conceive and design a final year CDIO capstone course. Both the student teamwork structure as well as the complex engineering system itself addressed in the project are described in terms of entities, links, form and function, thereby pointing out their formal and functional interaction. The ultimate goal of the Systems thinking perspective is, given the necessary ingredients, to try maximizing the chances of the emergence of a fruitful capstone course, namely a culminating project that yields a set of students qualified to CDIO complex engineering systems.

    Given the all-pervasiveness of Systems thinking -which consists of thinking about things as systemsas a way of reasoning, in this work we will describe its application to make an interpretation of how to conceive and design a final year CDIO capstone course. Both the student teamwork structure as well as the complex engineering system itself addressed in the project are described in terms of entities, links, form and function, thereby pointing out their formal and functional interaction. The ultimate goal of the Systems thinking perspective is, given the necessary ingredients, to try maximizing the chances of the emergence of a fruitful capstone course, namely a culminating project that yields a set of students qualified to CDIO complex engineering systems.

  • Maximizing efficiency through impedance matching from a circuit-centric model of non-radiative resonant wireless power transfer

     Bou Balust, Elisenda; Sedwick, Raymond; Alarcon Cot, Eduardo Jose
    IEEE International Symposium on Circuits and Systems
    p. 29-32
    DOI: 10.1109/ISCAS.2013.6571774
    Presentation's date: 2013-05-21
    Presentation of work at congresses

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    Recent research in wireless power transfer (WPT) using resonant inductive coupling has demonstrated very high efficiencies (above 40%) at large distances compared to the transmitting element dimensions, thereby exponentially increasing the number of potential applications of WPT. Since resonant inductive coupling is a very multidisciplinary field, different approaches have been proposed to predict the behaviour of these systems from the physical theory of resonators (coupled-mode theory), reflected load theory and circuit theory. Also, there is in this field a heterogeneous definition of metrics without a clear optimization process. In this article we unify the different metrics and demonstrate how to maximize the power transfer efficiency in a non-radiative resonant wireless power transfer link from a circuit-centric point of view providing design guidelines in terms of optimal load impedance, optimal source impedance and optimal distance between coils.

  • Interference analysis on resonant inductive coupled wireless power transfer

     Bou Balust, Elisenda; Alarcon Cot, Eduardo Jose; Sedwick, Raymond; Fisher, Peter
    IEEE International Symposium on Circuits and Systems
    p. 2783-2786
    DOI: 10.1109/ISCAS.2013.6572456
    Presentation's date: 2013-05-22
    Presentation of work at congresses

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    Resonant Inductive Coupling Wireless Power Transfer is a key technology to provide an efficient and harmless wireless energy channel to consumer electronics, biomedical implants and wireless sensor networks. However, there are two factors that are limiting the applicability of this technology: the effects of distance variation between transmitter and receiver and the effects of interfering objects. While distance variation in WPT has been thoroughly studied, the effects of interfering objects in resonant inductive coupling links are still unclear. In this article we propose a new circuit-based analytical model that predicts the behavior of a resonant inductive coupled link in the presence of interfering objects and verify the obtained results with a Finite Element Field Solver.

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    Output-capacitorless CMOS LDO regulator based on high slew-rate current-mode transconductance amplifier  Open access

     Saberkari, Alireza; Fathipour, Rasoul; Martínez García, Herminio; Poveda Lopez, Alberto; Alarcon Cot, Eduardo Jose
    IEEE International Symposium on Circuits and Systems
    p. 1484-1487
    DOI: 10.1109/ISCAS.2013.6572138
    Presentation's date: 2013-05-21
    Presentation of work at congresses

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    A low quiescent current output-capacitorless CMOS LDO regulator based on a high slew-rate current-mode transconductance amplifier (CTA) as an error amplifier is presented. Load transient characteristic of the proposed LDO is improved even at low quiescent currents, by using a local common-mode feedback (LCMFB) in the proposed CTA. This provides an increase in the order of transfer characteristic of the circuit, thereby enhancing the slew-rate at the gate of pass transistor. The proposed CTA-based LDO topology has been designed and post-layout simulated in HSPICE, in a 0.18 µm CMOS process to supply a load current between 0-100 mA. Postlayout simulation results reveal that the proposed LDO is stable without any internal compensation strategy and with on-chip output capacitor or lumped parasitic capacitances at the output node between 10-100 pF.

    A low quiescent current output-capacitorless CMOS LDO regulator based on a high slew-rate current-mode transconductance amplifier (CTA) as an error amplifier is presented. Load transient characteristic of the proposed LDO is improved even at low quiescent currents, by using a local common-mode feedback (LCMFB) in the proposed CTA. This provides an increase in the order of transfer characteristic of the circuit, thereby enhancing the slew-rate at the gate of pass transistor. The proposed CTA-based LDO topology has been designed and post-layout simulated in HSPICE, in a 0.18 μm CMOS process to supply a load current between 0-100 mA. Postlayout simulation results reveal that the proposed LDO is stable without any internal compensation strategy and with on-chip output capacitor or lumped parasitic capacitances at the output node between 10-100 pF.

  • Technologies for electric current sensors

     Velasco Quesada, Guillermo; Conesa Roca, Alfonso; Roman Lumbreras, Manuel
    Date of publication: 2013-05-22
    Book chapter

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  • Area and laser power scalability analysis in photonic networks-on-chip

     Abadal Cavalle, Sergi; Cabellos Aparicio, Alberto; Lazaro Villa, Jose Antonio; Nemirovsky, Mario; Alarcon Cot, Eduardo Jose; Sole Pareta, Josep
    International Conference on Optical Network Design and Modeling
    p. 131-136
    Presentation's date: 2013-04-18
    Presentation of work at congresses

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    In the last decade, the field of microprocessor architecture has seen the rise of multicore processors, which consist of the interconnection of a set of independent processing units or cores in the same chip. As the number of cores per multiprocessor increases, the bandwidth and energy requirements for their interconnection networks grow exponentially and it is expected that conventional on-chip wires will not be able to meet such demands. Alternatively, nanophotonics has been regarded as a strong candidate for chip communication since it could provide high bandwidth with low area and energy footprints. However, issues such as the unavailability of efficient on-chip light sources or the difficulty of implementing all-optical buffering or header processing hinder the development of scalable photonic on-chip networks. In this paper, the area and laser power of several photonic on-chip network proposals is analytically modeled and its scalability is evaluated. Also, a graphene-based hybrid approach is presented

    In the last decade, the field of microprocessor architecture has seen the rise of multicore processors, which consist of the interconnection of a set of independent processing units or cores in the same chip. As the number of cores per multiprocessor increases, the bandwidth and energy requirements for their interconnection networks grow exponentially and it is expected that conventional on-chip wires will not be able to meet such demands. Alternatively, nanophotonics has been regarded as a strong candidate for chip communication since it could provide high bandwidth with low area and energy footprints. However, issues such as the unavailability of efficient on-chip light sources or the difficulty of implementing all-optical buffering or header processing hinder the development of scalable photonic on-chip networks. In this paper, the area and laser power of several photonic on-chip network proposals is analytically modeled and its scalability is evaluated. Also, a graphene-based hybrid wireless/optical-wired approach is presented, aiming at enabling end-to-end photonic on-chip networks to scale beyond thousands of cores

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    Who develops ICT resources in higher education? Applied research and contributions of the university community in developing countries: the case of Addis Ababa University and Wollo University (Ethiopia)  Open access

     Berdun Peñato, Jesus; Vidal Lopez, Eva Maria; Mariam, Sebsibe H.
    Congreso Nacional Universidad y Cooperación al Desarrollo
    p. 149
    Presentation's date: 2013-04-24
    Presentation of work at congresses

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    ICTs are a potential means of development, specially for universities and other education and research institutions, as an essential part of the national development engine. The association AUCOOP, with the support of Center of Cooperation for Development from Universitat Politècnica de Catalunya (CCD-UPC), and Addis Ababa University (AAU), have been working since 2009 in different collaborative actions related to the development of ICT resources in one of the new Ethiopian universities, Wollo University (WU), with the vision to extend the outcomes of this collaboration to other higher education institutions in Ethiopia.

    ICTs are a potential means of development, specially for universities and other education and research institutions, as an essential part of the national development engine. The association AUCOOP, with the support of Center of Cooperation for Development from Universitat Politècnica de Catalunya (CCD-UPC), and Addis Ababa University (AAU), have been working since 2009 in different collaborative actions related to the development of ICT resources in one of the new Ethiopian universities, Wollo University (WU), with the vision to extend the outcomes of this collaboration to other higher education institutions in Ethiopia.

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    The Machreck Energy Development - Solar project MED-Solar  Open access

     Velasco Quesada, Guillermo; Guinjoan Gispert, Francisco; Pique Lopez, Robert; Roman Lumbreras, Manuel; Vallvé, Xavier; Tarragó, J.; Bugatti, N.
    International Multi-Conference on Systems, Signals and Devices
    p. 6-13
    Presentation's date: 2013-03-19
    Presentation of work at congresses

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    The aim of this communication is to introduce the project MED-Solar, acronym of Machrek Energy Development. This project is part of the new European Neighborhood Policy (ENP), policy that seeks to reinforce relations with neighboring countries to the east and south in order to promote prosperity, stability and security at its borders. The main objective of this project is the promotion and implementation of innovative technologies and know-how transfer in the field of solar energy, including that stemming from private sector, and that may be implemented in particular or public facilities through public procurement processes.