Recursos de colección

Archivo Digital UPM (101.630 recursos)

This is an institutional repository providing access to the research output of the institution. Primarily contains thesis.

Materia = Electrónica

Mostrando recursos 1 - 20 de 707

  1. Empiric k·p Hamiltonian calculation of the band-to-band photon absorption in semiconductors

    Luque López, Antonio; Panchak, A.; Mellor Null, Alexander Virgil; Vlasov, A.; Martí Vega, Antonio; Andreev, V.
    The Empiric k·p Hamiltonian method is usually applied to nanostructured semiconductors. In this paper, it is applied to a homogeneous semiconductor in order to check the adequacy of the method. In this case, the solutions of the diagonalized Hamiltonian, as well as the envelope functions, are plane waves. The procedure is applied to the GaAs and the interband absorption coefficients are calculated. They result in reasonable agreement with the measured values, further supporting the adequacy of the Empiric k·p Hamiltonian method.

  2. Modeling sub-threshold slope and DIBL mismatch of sub-22nm FinFet

    Royer del Barrio, Pablo; López Vallejo, Marisa
    A great challenge for future information technologies is building reliable systems on top of unreliable components. Parameters of modern and future technology devices are affected by severe levels of process variability and devices will degrade and even fail during the normal lifeDme of the chip due to aging mechanisms. These extreme levels of variability are caused by the high device miniaturizaDon and the random placement of individual atoms. Variability is considered a "red brick" by the InternaDonal Technology Roadmap for Semiconductors. The session is devoted to this topic presenDng research experiences from the Spanish Network on Variability called VARIABLES. In...

  3. Laboratorio remoto eLab3D: un entorno innovador para el aprendizaje de competencias prácticas en electrónica

    López Gregorio, Sergio; Carpeño Ruiz, Antonio; Arriaga Garcia de Andoain, Jesus Maria; Arcas Castro, Guillermo de; Contreras, Daniel; Salazar, José; Barras, Miguel
    Este artículo muestra la utilización de las nuevas tecnologías al servicio del aprendizaje de competencias prácticas en electrónica, siendo un ejemplo de adaptación de los recursos educativos a diferentes contextos y necesidades. Se trata de un laboratorio remoto en el que la adecuada complementación de un hardware configurable y un software de última generación permite al estudiante realizar prácticas de electrónica y diseño de circuitos en un mundo virtual 3D. El usuario dispone de un avatar e interacciona con réplicas virtuales de instrumentos, placas de circuitos, componentes o cables de forma muy similar a como se opera en un laboratorio...

  4. Evaluation of the utilization of electric vehicles for building energy management in hotels

    Gamallo, Carlos; Álvaro, Roberto; Fraile Ardanuy, José Jesús; González, Jairo; Fuentes Gomariz, Manuel
    Governments are working in new policies to slow down total energy consumption and greenhouse gases (GHG) emissions, promoting the deployment of electric vehicles (EVs) in all countries. In order to facilitate this deployment and help to reduce the final costs of their batteries, additional utilization of EVs when those are parked has been proposed. EVs can be used to minimize the total electricity cost of buildings (named vehicle to building applications, V2B). In this paper an economic evaluation of EVs in the Building Energy Management System is shown. The optimal storage capacity and its equivalent number of EVs are determined....

  5. A low-area reference-free power supply sensor

    Benito Sánchez, Carlos; Ituero Herrero, Pablo; López Vallejo, Marisa
    Power supply unpredictable uctuations jeopardize the functioning of several types of current electronic systems. This work presents a power supply sensor based on a voltage divider followed by buffer-comparator cells employing just MOSFET transistors and provides a digital output. The divider outputs are designed to change more slowly than the thresholds of the comparators, in this way the sensor is able to detect voltage droops. The sensor is implemented in a 65nm technology node occupying an area of 2700?m2 and displaying a power consumption of 50?W. It is designed to work with no voltage reference and with no clock and...

  6. Leakage and temperature aware server control for improving energy efficiency in data centers

    Zapater Sancho, Marina; Ayala Rodrigo, José Luis; Moya Fernández, José Manuel; Vaidyanathan, Kalyan; Gross, Kenny; Coskun, Ayse K.
    Reducing the energy consumption for computation and cooling in servers is a major challenge considering the data center energy costs today. To ensure energy-efficient operation of servers in data centers, the relationship among computa- tional power, temperature, leakage, and cooling power needs to be analyzed. By means of an innovative setup that enables monitoring and controlling the computing and cooling power consumption separately on a commercial enterprise server, this paper studies temperature-leakage-energy tradeoffs, obtaining an empirical model for the leakage component. Using this model, we design a controller that continuously seeks and settles at the optimal fan speed to minimize...

  7. On the leakage-power modeling for optimal server operation

    Arroba García, Patricia; Zapater Sancho, Marina; Ayala, José L.; Moya Fernández, José Manuel; Olcoz, Katzalin; Hermida, Román
    Leakage power consumption is a com- ponent of the total power consumption in data cen- ters that is not traditionally considered in the set- point temperature of the room. However, the effect of this power component, increased with temperature, can determine the savings associated with the careful management of the cooling system, as well as the re- liability of the system. The work presented in this paper detects the need of addressing leakage power in order to achieve substantial savings in the energy consumption of servers. In particular, our work shows that, by a careful detection and management of two...

  8. DIseño e implementación de un control adaptativo para obteNer ZVS en un convertidor trifasico de puente activo para aplicaciones de vehículos eléctricos

    Molina García, José María
    En este Trabajo Fin de Máster se ha realizado un estudio sobre un convertidor trifásico de doble puente activo con una red auxiliar, con objeto de conseguir ZVS. Como aportación, este trabajo diseña e implementa un control adaptativo para la red auxiliar ARCN, con el objetivo de disminuir las pérdidas a su valor mínimo.

  9. Receptores homodinos a 300 GHz basados en tecnología CMOS

    González Posadas, Vicente; Segovia Vargas, Daniel; Montero de Paz, Javier; Portillo López-Mingo, Álvaro; Crooks, Jamie; Huggard, Peter G.; García Muñoz, Enrique; Alderman, B.; Turchetta, R.
    Using CMOS transistors for terahertz detection is currently a disruptive technology that offers the direct integration of a terahertz detector with video preamplifiers. The detectors are based on the resistive mixer concept and its performance mainly depends on the following parameters: type of antenna, electrical parameters (gate to drain capacitor and channel length of the CMOS device) and foundry. Two different 300 GHz detectors are discussed: a single transistor detector with a broadband antenna and a differential pair driven by a resonant patch antenna.

  10. Evaluation, energy optimization, and spectrum analysis of an artificial noise technique to improve CWSN security

    Blesa Martínez, Javier; Araujo Pinto, Álvaro; Romero Perales, Elena; Nieto-Taladriz García, Octavio
    This paper presents the security evaluation, energy consumption optimization, and spectrum scarcity analysis of artificial noise techniques to increase physical-layer security in Cognitive Wireless Sensor Networks (CWSNs). These techniques introduce noise into the spectrum in order to hide real information. Nevertheless, they directly affect two important parameters in Cognitive Wireless Sensor Networks (CWSNs), energy consumption and spectrum utilization. Both are affected because the number of packets transmitted by the network and the active period of the nodes increase. Security evaluation demonstrates that these techniques are effective against eavesdropper attacks, but also optimization allows for the implementation of these approaches in...

  11. NGCPV: a new generation of concentrator photovoltaic cells, modules and systems

    Datas Medina, Alejandro; Cristóbal López, Ana Belén; Sala Pano, Gabriel; Anton Hernandez, Ignacio; Miñano Dominguez, Juan Carlos; Benitez Gimenez, Pablo; Bett, Andreas W.; Siefer, Gerald; Ekins-Daukes, Ned; Roca, Franco; Cancro, C.; Luque-Heredia, Ignacio; Warmuth, Werner; Baudrit, Mathieu; Okada, Y.; Sugiyama, M.; Hishikawa, Y.; Takamoto, Tatsuya; Araki, Kenji; Fukuyama, A.; Nishioka, K.; Suzuki, H.; Kuze, N.; Moriyasu, Y.; Kita, T.; Kotagiri, Akira; Kojima, N.; Martí Vega, Antonio; Yamaguchi, M.; Luque López, Antonio
    Starting on June 2011, NGCPV is the first project funded jointly between the European Commission (EC) and the New Energy and Industrial Technology Development Organization (NEDO) of Japan to research on new generation concentration photovoltaics (CPV). The Project, through a collaborative research between seven European and nine Japanese leading research centers in the field of CPV, aims at lowering the cost of the CPVproduced photovoltaic kWh down to 5 ?cents. The main objective of the project is to improve the present concentrator cell, module and system efficiency, as well as developing advanced characterization tools for CPV components and systems. As...

  12. Ratio-based temperature-sensing technique hardened against nanometer process variations

    Ituero Herrero, Pablo; López Vallejo, Marisa
    This letter presents a temperature-sensing technique on the basis of the temperature dependency of MOSFET leakage currents. To mitigate the effects of process variation, the ratio of two different leakage current measurements is calculated. Simulations show that this ratio is robust to process spread. The resulting sensor is quite small-0.0016 mm2 including an analog-to-digital conversion-and very energy efficient, consuming less than 640 pJ/conversion. After a two-point calibration, the accuracy in a range of 40°C-110°C is less than 1.5°C , which makes the technique suitable for thermal management applications.

  13. Floating-point exponentiation units for reconfigurable computing

    Dinechin, Florent de; Echeverría Aramendi, Pedro; López Vallejo, Marisa; Pasca, Bogdan
    The high performance and capacity of current FPGAs makes them suitable as acceleration co-processors. This article studies the implementation, for such accelerators, of the floating-point power function xy as defined by the C99 and IEEE 754-2008 standards, generalized here to arbitrary exponent and mantissa sizes. Last-bit accuracy at the smallest possible cost is obtained thanks to a careful study of the various subcomponents: a floating-point logarithm, a modified floating-point exponential, and a truncated floating-point multiplier. A parameterized architecture generator in the open-source FloPoCo project is presented in details and evaluated.

  14. Design techniques for xilinx virtex FPGA configuration memory scrubbers

    Herrera Alzu, Ignacio; López Vallejo, Marisa
    SRAM-based FPGAs are in-field reconfigurable an unlimited number of times. This characteristic, together with their high performance and high logic density, proves to be very convenient for a number of ground and space level applications. One drawback of this technology is that it is susceptible to ionizing radiation, and this sensitivity increases with technology scaling. This is a first order concern for applications in harsh radiation environments, and starts to be a concern for high reliability ground applications. Several techniques exist for coping with radiation effects at user application. In order to be effective they need to be complemented with...

  15. ‘State-of-the-art’ of building integrated photovoltaic products

    Cerón, Isabel; Caamaño Martín, Estefanía; Neila Gonzalez, Francisco Javier
    During the last decades, the photovoltaic (PV) modules and their associated architectural materials are increasingly being incorporated into the construction of the building envelope such as façade, roof and skylights in the urban centers. This paper analyzes the-state-of-the-art of the PV elements and construction materials which are advertised as BIPV-products at the most important companies in the world. For this purpose 136 companies and 445 PV elements have been investigated and analyzed from a technical and architectural point of view. Also, the study has been divided into two main groups according to industry which producing the product: BIPV-Modules, which comes from...

  16. A 0.0016 mm(2) 0.64 nJ leakage-based CMOS temperature sensor

    Ituero Herrero, Pablo; López Vallejo, Marisa; López Barrio, Carlos Alberto
    This paper presents a CMOS temperature sensor based on the thermal dependencies of the leakage currents targeting the 65 nm node. To compensate for the effect of process fluctuations, the proposed sensor realizes the ratio of two measures of the time it takes a capacitor to discharge through a transistor in the subthreshold regime. Furthermore, a novel charging mechanism for the capacitor is proposed to further increase the robustness against fabrication variability. The sensor, including digitization and interfacing, occupies 0.0016 mm2 and has an energy consumption of 47.7–633 pJ per sample. The resolution of the sensor is 0.28 °C, and...

  17. FPGA-Based Wireless Sensor Node Architecture for High Performance Applications

    Valverde Alcalá, Juan
    While for years traditional wireless sensor nodes have been based on ultra-low power microcontrollers with sufficient but limited computing power, the complexity and number of tasks of today’s applications are constantly increasing. Increasing the node duty cycle is not feasible in all cases, so in many cases more computing power is required. This extra computing power may be achieved by either more powerful microcontrollers, though more power consumption or, in general, any solution capable of accelerating task execution. At this point, the use of hardware based, and in particular FPGA solutions, might appear as a candidate technology, since though power...

  18. Image processing methods for human brain connectivity analysis from in-vivo diffusion MRI

    Esteban Sanz-Dranguet, Oscar
    In this PhD Thesis proposal, the principles of diffusion MRI (dMRI) in its application to the human brain mapping of connectivity are reviewed. The background section covers the fundamentals of dMRI, with special focus on those related to the distortions caused by susceptibility inhomogeneity across tissues. Also, a deep survey of available correction methodologies for this common artifact of dMRI is presented. Two methodological approaches to improved correction are introduced. Finally, the PhD proposal describes its objectives, the research plan, and the necessary resources.

  19. Steady state analysis of a storage integrated solar thermophotovoltaic (SISTPV) system

    Datas Medina, Alejandro; Chubb, Donald L.; Veeraragavan, Anand
    This paper presents the theoretical analysis of a storage integrated solar thermophotovoltaic (SISTPV) system operating in steady state. These systems combine thermophotovoltaic (TPV) technology and high temperature thermal storage phase-change materials (PCM) in the same unit, providing a great potential in terms of efficiency, cost reduction and storage energy density. The main attraction in the proposed system is its simplicity and modularity compared to conventional Concentrated Solar Power (CSP) technologies. This is mainly due to the absence of moving parts. In this paper we analyze the use of Silicon as the phase change material (PCM). Silicon is an excellent candidate...

  20. Interband absorption of photons by extended states in intermediate band solar cells

    Luque López, Antonio; Mellor Null, Alexander Virgil; Ramiro Gonzalez, Iñigo; Antolín Fernández, Elisa; Tobías Galicia, Ignacio; Martí Vega, Antonio
    This paper considers sub-bandgap photon absorption in an InAs/GaAs quantum dot matrix. Absorption coefficients are calculated for transitions from the extended states in the valence band to confined states in the conduction band. This completes a previous body of work in which transitions between bound states were calculated. The calculations are based on the empirical k·p Hamiltonian considering the quantum dots as parallelepipeds. The extended states may be only partially extended?in one or two dimensions?or extended in all three dimensions. It is found that extended-to-bound transitions are, in general, weaker than bound-to-bound transitions, and that the former are weaker when...

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