5,074 research outputs found

    Advanced analog television study final report, 4 nov. - 19 dec. 1963

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    Information bandwidth reduction for analog television signals - Description of multiple interlace syste

    SIRU development. Volume 1: System development

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    A complete description of the development and initial evaluation of the Strapdown Inertial Reference Unit (SIRU) system is reported. System development documents the system mechanization with the analytic formulation for fault detection and isolation processing structure; the hardware redundancy design and the individual modularity features; the computational structure and facilities; and the initial subsystem evaluation results

    Low-Power Design of Digital VLSI Circuits around the Point of First Failure

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    As an increase of intelligent and self-powered devices is forecasted for our future everyday life, the implementation of energy-autonomous devices that can wirelessly communicate data from sensors is crucial. Even though techniques such as voltage scaling proved to effectively reduce the energy consumption of digital circuits, additional energy savings are still required for a longer battery life. One of the main limitations of essentially any low-energy technique is the potential degradation of the quality of service (QoS). Thus, a thorough understanding of how circuits behave when operated around the point of first failure (PoFF) is key for the effective application of conventional energy-efficient methods as well as for the development of future low-energy techniques. In this thesis, a variety of circuits, techniques, and tools is described to reduce the energy consumption in digital systems when operated either in the safe and conservative exact region, close to the PoFF, or even inside the inexact region. A straightforward approach to reduce the power consumed by clock distribution while safely operating in the exact region is dual-edge-triggered (DET) clocking. However, the DET approach is rarely taken, primarily due to the perceived complexity of its integration. In this thesis, a fully automated design flow is introduced for applying DET clocking to a conventional single-edge-triggered (SET) design. In addition, the first static true-single-phase-clock DET flip-flop (DET-FF) that completely avoids clock-overlap hazards of DET registers is proposed. Even though the correct timing of synchronous circuits is ensured in worst-case conditions, the critical path might not always be excited. Thus, dynamic clock adjustment (DCA) has been proposed to trim any available dynamic timing margin by changing the operating clock frequency at runtime. This thesis describes a dynamically-adjustable clock generator (DCG) capable of modifying the period of the produced clock signal on a cycle-by-cycle basis that enables the DCA technique. In addition, a timing-monitoring sequential (TMS) that detects input transitions on either one of the clock phases to enable the selection of the best timing-monitoring strategy at runtime is proposed. Energy-quality scaling techniques aimat trading lower energy consumption for a small degradation on the QoS whenever approximations can be tolerated. In this thesis, a low-power methodology for the perturbation of baseline coefficients in reconfigurable finite impulse response (FIR) filters is proposed. The baseline coefficients are optimized to reduce the switching activity of the multipliers in the FIR filter, enabling the possibility of scaling the power consumption of the filter at runtime. The area as well as the leakage power of many system-on-chips is often dominated by embedded memories. Gain-cell embedded DRAM (GC-eDRAM) is a compact, low-power and CMOS-compatible alternative to the conventional static random-access memory (SRAM) when a higher memory density is desired. However, due to GC-eDRAMs relying on many interdependent variables, the adaptation of existing memories and the design of future GCeDRAMs prove to be highly complex tasks. Thus, the first modeling tool that estimates timing, memory availability, bandwidth, and area of GC-eDRAMs for a fast exploration of their design space is proposed in this thesis

    A review of advances in pixel detectors for experiments with high rate and radiation

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    The Large Hadron Collider (LHC) experiments ATLAS and CMS have established hybrid pixel detectors as the instrument of choice for particle tracking and vertexing in high rate and radiation environments, as they operate close to the LHC interaction points. With the High Luminosity-LHC upgrade now in sight, for which the tracking detectors will be completely replaced, new generations of pixel detectors are being devised. They have to address enormous challenges in terms of data throughput and radiation levels, ionizing and non-ionizing, that harm the sensing and readout parts of pixel detectors alike. Advances in microelectronics and microprocessing technologies now enable large scale detector designs with unprecedented performance in measurement precision (space and time), radiation hard sensors and readout chips, hybridization techniques, lightweight supports, and fully monolithic approaches to meet these challenges. This paper reviews the world-wide effort on these developments.Comment: 84 pages with 46 figures. Review article.For submission to Rep. Prog. Phy

    Design considerations for a monolithic, GaAs, dual-mode, QPSK/QASK, high-throughput rate transceiver

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    A monolithic, GaAs, dual mode, quadrature amplitude shift keying and quadrature phase shift keying transceiver with one and two billion bits per second data rate is being considered to achieve a low power, small and ultra high speed communication system for satellite as well as terrestrial purposes. Recent GaAs integrated circuit achievements are surveyed and their constituent device types are evaluated. Design considerations, on an elemental level, of the entire modem are further included for monolithic realization with practical fabrication techniques. Numerous device types, with practical monolithic compatability, are used in the design of functional blocks with sufficient performances for realization of the transceiver

    Ultra high-density hybrid pixel sensors for the detection of charge particles

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    L'abstract è presente nell'allegato / the abstract is in the attachmen

    Belle II Technical Design Report

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    The Belle detector at the KEKB electron-positron collider has collected almost 1 billion Y(4S) events in its decade of operation. Super-KEKB, an upgrade of KEKB is under construction, to increase the luminosity by two orders of magnitude during a three-year shutdown, with an ultimate goal of 8E35 /cm^2 /s luminosity. To exploit the increased luminosity, an upgrade of the Belle detector has been proposed. A new international collaboration Belle-II, is being formed. The Technical Design Report presents physics motivation, basic methods of the accelerator upgrade, as well as key improvements of the detector.Comment: Edited by: Z. Dole\v{z}al and S. Un

    A depolarization and attenuation experiment using the CTS satellite. Volume 1: Experiment description

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    An experiment for measuring precipitation attenuation and depolarization on the Communications Technology Satellite (CTS) 11.7 GHz downlink is described. Attenuation and depolarization of the signal received from the spacecraft is monitored on a 24 hour basis. Data is correlated with ground weather conditions. Theoretical models for millimeter wave propagation through rain are refined for maximum agreement with observed data. Techniques are developed for predicting and mimimizing the effects of rain scatter and depolarization on future satellite communication systems

    Design of variation-tolerant synchronizers for multiple clock and voltage domains

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    PhD ThesisParametric variability increasingly affects the performance of electronic circuits as the fabrication technology has reached the level of 32nm and beyond. These parameters may include transistor Process parameters (such as threshold voltage), supply Voltage and Temperature (PVT), all of which could have a significant impact on the speed and power consumption of the circuit, particularly if the variations exceed the design margins. As systems are designed with more asynchronous protocols, there is a need for highly robust synchronizers and arbiters. These components are often used as interfaces between communication links of different timing domains as well as sampling devices for asynchronous inputs coming from external components. These applications have created a need for new robust designs of synchronizers and arbiters that can tolerate process, voltage and temperature variations. The aim of this study was to investigate how synchronizers and arbiters should be designed to tolerate parametric variations. All investigations focused mainly on circuit-level and transistor level designs and were modeled and simulated in the UMC90nm CMOS technology process. Analog simulations were used to measure timing parameters and power consumption along with a “Monte Carlo” statistical analysis to account for process variations. Two main components of synchronizers and arbiters were primarily investigated: flip-flop and mutual-exclusion element (MUTEX). Both components can violate the input timing conditions, setup and hold window times, which could cause metastability inside their bistable elements and possibly end in failures. The mean-time between failures is an important reliability feature of any synchronizer delay through the synchronizer. The MUTEX study focused on the classical circuit, in addition to a number of tolerance, based on increasing internal gain by adding current sources, reducing the capacitive loading, boosting the transconductance of the latch, compensating the existing Miller capacitance, and adding asymmetry to maneuver the metastable point. The results showed that some circuits had little or almost no improvements, while five techniques showed significant improvements by reducing τ and maintaining high tolerance. Three design approaches are proposed to provide variation-tolerant synchronizers. wagging synchronizer proposed to First, the is significantly increase reliability over that of the conventional two flip-flop synchronizer. The robustness of the wagging technique can be enhanced by using robust τ latches or adding one more cycle of synchronization. The second approach is the Metastability Auto-Detection and Correction (MADAC) latch which relies on swiftly detecting a metastable event and correcting it by enforcing the previously stored logic value. This technique significantly reduces the resolution time down from uncertain synchronization technique is proposed to transfer signals between Multiple- Voltage Multiple-Clock Domains (MVD/MCD) that do not require conventional level-shifters between the domains or multiple power supplies within each domain. This interface circuit uses a synchronous set and feedback reset protocol which provides level-shifting and synchronization of all signals between the domains, from a wide range of voltage-supplies and clock frequencies. Overall, synchronizer circuits can tolerate variations to a greater extent by employing the wagging technique or using a MADAC latch, while MUTEX tolerance can suffice with small circuit modifications. Communication between MVD/MCD can be achieved by an asynchronous handshake without a need for adding level-shifters.The Saudi Arabian Embassy in London, Umm Al-Qura University, Saudi Arabi

    Design, Simulations and Development of a Miniature Detector System for Radiation Monitoring on Satellites

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    Space environment is particularly harsh for human activity and human assets. As human activity expands rapidly into space, it becomes ever more urgent to monitor the space environment in situ and in real time. This thesis aims to study a low re-source, miniature detector system to be employed on the satellites to monitor the in-situ space environment particularly for the hazard high energy particles. The vision is that every satellite even at small scale can afford to carry one such detector sys-tem. The core technology used in the detector system is scintillator + SiPM. The scintillator is a mature and traditional radiation detector and the SiPM is the latest generation of photon detector, which rapidly replaces the role of traditional PMT. Development of such detector system requires knowledge over space environment, detector material and geometry, electronics, data processing and more. This thesis tries to have a as complete coverage as possible to demonstrate the flow and the structure of such development. The thesis closely couples the theoretical knowledge to engineering realization. A detector system prototype for pioneering study is fully built and tested from end to end. This serves as the first stepping stone for the path to the full-scale space instrument
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