18,619 research outputs found

    Communication Subsystems for Emerging Wireless Technologies

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    The paper describes a multi-disciplinary design of modern communication systems. The design starts with the analysis of a system in order to define requirements on its individual components. The design exploits proper models of communication channels to adapt the systems to expected transmission conditions. Input filtering of signals both in the frequency domain and in the spatial domain is ensured by a properly designed antenna. Further signal processing (amplification and further filtering) is done by electronics circuits. Finally, signal processing techniques are applied to yield information about current properties of frequency spectrum and to distribute the transmission over free subcarrier channels

    Novel active function blocks and their applications in frequency filters and quadrature oscillators

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    KmitočtovĂ© filtry a sinusoidnĂ­ oscilĂĄtory jsou lineĂĄrnĂ­ elektronickĂ© obvody, kterĂ© jsou pouĆŸĂ­vĂĄny v ĆĄirokĂ© oblasti elektroniky a jsou zĂĄkladnĂ­mi stavebnĂ­mi bloky v analogovĂ©m zpracovĂĄnĂ­ signĂĄlu. V poslednĂ­ dekĂĄdě pro tento Ășčel bylo prezentovĂĄno velkĂ© mnoĆŸstvĂ­ stavebnĂ­ch funkčnĂ­ch blokĆŻ. V letech 2000 a 2006 na Ústavu telekomunikacĂ­, VUT v Brně byly definovĂĄny univerzĂĄlnĂ­ proudovĂœ konvejor (UCC) a univerzĂĄlnĂ­ napět'ovĂœ konvejor (UVC) a vyrobeny ve spoluprĂĄci s firmou AMI Semiconductor Czech, Ltd. OvĆĄem, stĂĄle existuje poĆŸadavek na vĂœvoj novĂœch aktivnĂ­ch prvkĆŻ, kterĂ© nabĂ­zejĂ­ novĂ© vĂœhody. HlavnĂ­ pƙínos prĂĄce proto spočívĂĄ v definici dalĆĄĂ­ch pĆŻvodnĂ­ch aktivnĂ­ch stavebnĂ­ch blokĆŻ jako jsou differential-input buffered and transconductance amplifier (DBTA), current follower transconductance amplifier (CFTA), z-copy current-controlled current inverting transconductance amplifier (ZC-CCCITA), generalized current follower differential input transconductance amplifier (GCFDITA), voltage gain-controlled modified current-feedback operational amplifier (VGC-MCFOA), a minus-type current-controlled third-generation voltage conveyor (CC-VCIII-). PomocĂ­ navrĆŸenĂœch aktivnĂ­ch stavebnĂ­ch blokĆŻ byly prezentovĂĄny pĆŻvodnĂ­ zapojenĂ­ fĂĄzovacĂ­ch člĂĄnkĆŻ prvnĂ­ho ƙádu, univerzĂĄlnĂ­ filtry druhĂ©ho ƙádu, ekvivalenty obvodu typu KHN, inverznĂ­ filtry, aktivnĂ­ simulĂĄtory uzemněnĂ©ho induktoru a kvadraturnĂ­ sinusoidnĂ­ oscilĂĄtory pracujĂ­cĂ­ v proudovĂ©m, napět'ovĂ©m a smĂ­ĆĄenĂ©m mĂłdu. ChovĂĄnĂ­ navrĆŸenĂœch obvodĆŻ byla ověƙena simulacĂ­ v prostƙedĂ­ SPICE a ve vybranĂœch pƙípadech experimentĂĄlnĂ­m měƙenĂ­m.Frequency filters and sinusoidal oscillators are linear electric circuits that are used in wide area of electronics and also are the basic building blocks in analogue signal processing. In the last decade, huge number of active building blocks (ABBs) were presented for this purpose. In 2000 and 2006, the universal current conveyor (UCC) and the universal voltage conveyor (UVC), respectively, were designed at the Department of Telecommunication, BUT, Brno, and produced in cooperation with AMI Semiconductor Czech, Ltd. There is still the need to develop new active elements that offer new advantages. The main contribution of this thesis is, therefore, the definition of other novel ABBs such as the differential-input buffered and transconductance amplifier (DBTA), the current follower transconductance amplifier (CFTA), the z-copy current-controlled current inverting transconductance amplifier (ZC-CCCITA), the generalized current follower differential input transconductance amplifier (GCFDITA), the voltage gain-controlled modified current-feedback operational amplifier (VGC-MCFOA), and the minus-type current-controlled third-generation voltage conveyor (CC-VCIII-). Using the proposed ABBs, novel structures of first-order all-pass filters, second-order universal filters, KHN-equivalent circuits, inverse filters, active grounded inductance simulators, and quadrature sinusoidal oscillators working in the current-, voltage-, or mixed-mode are presented. The behavior of the proposed circuits has been verified by SPICE simulations and in selected cases also by experimental measurements.

    The ArgoNeuT Detector in the NuMI Low-Energy beam line at Fermilab

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    The ArgoNeuT liquid argon time projection chamber has collected thousands of neutrino and antineutrino events during an extended run period in the NuMI beam-line at Fermilab. This paper focuses on the main aspects of the detector layout and related technical features, including the cryogenic equipment, time projection chamber, read-out electronics, and off-line data treatment. The detector commissioning phase, physics run, and first neutrino event displays are also reported. The characterization of the main working parameters of the detector during data-taking, the ionization electron drift velocity and lifetime in liquid argon, as obtained from through-going muon data complete the present report.Comment: 43 pages, 27 figures, 5 tables - update referenc

    European White Book on Real-Time Power Hardware in the Loop Testing : DERlab Report No. R- 005.0

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    The European White Book on Real-Time-Powerhardware-in-the-Loop testing is intended to serve as a reference document on the future of testing of electrical power equipment, with speciïŹ c focus on the emerging hardware-in-the-loop activities and application thereof within testing facilities and procedures. It will provide an outlook of how this powerful tool can be utilised to support the development, testing and validation of speciïŹ cally DER equipment. It aims to report on international experience gained thus far and provides case studies on developments and speciïŹ c technical issues, such as the hardware/software interface. This white book compliments the already existing series of DERlab European white books, covering topics such as grid-inverters and grid-connected storag

    Quantum control theory and applications: A survey

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    This paper presents a survey on quantum control theory and applications from a control systems perspective. Some of the basic concepts and main developments (including open-loop control and closed-loop control) in quantum control theory are reviewed. In the area of open-loop quantum control, the paper surveys the notion of controllability for quantum systems and presents several control design strategies including optimal control, Lyapunov-based methodologies, variable structure control and quantum incoherent control. In the area of closed-loop quantum control, the paper reviews closed-loop learning control and several important issues related to quantum feedback control including quantum filtering, feedback stabilization, LQG control and robust quantum control.Comment: 38 pages, invited survey paper from a control systems perspective, some references are added, published versio

    CMOS design of chaotic oscillators using state variables: a monolithic Chua's circuit

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    This paper presents design considerations for monolithic implementation of piecewise-linear (PWL) dynamic systems in CMOS technology. Starting from a review of available CMOS circuit primitives and their respective merits and drawbacks, the paper proposes a synthesis approach for PWL dynamic systems, based on state-variable methods, and identifies the associated analog operators. The GmC approach, combining quasi-linear VCCS's, PWL VCCS's, and capacitors is then explored regarding the implementation of these operators. CMOS basic building blocks for the realization of the quasi-linear VCCS's and PWL VCCS's are presented and applied to design a Chua's circuit IC. The influence of GmC parasitics on the performance of dynamic PWL systems is illustrated through this example. Measured chaotic attractors from a Chua's circuit prototype are given. The prototype has been fabricated in a 2.4- mu m double-poly n-well CMOS technology, and occupies 0.35 mm/sup 2/, with a power consumption of 1.6 mW for a +or-2.5-V symmetric supply. Measurements show bifurcation toward a double-scroll Chua's attractor by changing a bias current

    Satellite remote sensing facility for oceanograhic applications

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    The project organization, design process, and construction of a Remote Sensing Facility at Scripps Institution of Oceanography at LaJolla, California are described. The facility is capable of receiving, processing, and displaying oceanographic data received from satellites. Data are primarily imaging data representing the multispectral ocean emissions and reflectances, and are accumulated during 8 to 10 minute satellite passes over the California coast. The most important feature of the facility is the reception and processing of satellite data in real time, allowing investigators to direct ships to areas of interest for on-site verifications and experiments

    Polarization entangled photon-pair source based on quantum nonlinear photonics and interferometry

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    We present a versatile, high-brightness, guided-wave source of polarization entangled photons, emitted at a telecom wavelength. Photon-pairs are generated using an integrated type-0 nonlinear waveguide, and subsequently prepared in a polarization entangled state via a stabilized fiber interferometer. We show that the single photon emission wavelength can be tuned over more than 50 nm, whereas the single photon spectral bandwidth can be chosen at will over more than five orders of magnitude (from 25 MHz to 4 THz). Moreover, by performing entanglement analysis, we demonstrate a high degree of control of the quantum state via the violation of the Bell inequalities by more than 40 standard deviations. This makes this scheme suitable for a wide range of quantum optics experiments, ranging from fundamental research to quantum information applications. We report on details of the setup, as well as on the characterization of all included components, previously outlined in F. Kaiser et al. (2013 Laser Phys. Lett. 10, 045202).Comment: 16 pages, 7 figure
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