6,976 research outputs found
Analog MIMO Radio-over-Copper: Prototype and Preliminary Experimental Results
Analog Multiple-Input Multiple-Output Radio-over-Copper (A-MIMO-RoC) is an
effective all-analog FrontHaul (FH) architecture that exploits any pre-existing
Local Area Network (LAN) cabling infrastructure of buildings to distribute
Radio-Frequency (RF) signals indoors. A-MIMO-RoC, by leveraging a fully analog
implementation, completely avoids any dedicated digital interface by using a
transparent end-to-end system, with consequent latency, bandwidth and cost
benefits. Usually, LAN cables are exploited mainly in the low-frequency
spectrum portion, mostly due to the moderate cable attenuation and crosstalk
among twisted-pairs. Unlike current systems based on LAN cables, the key
feature of the proposed platform is to exploit more efficiently the huge
bandwidth capability offered by LAN cables, that contain 4 twisted-pairs
reaching up to 500 MHz bandwidth/pair when the length is below 100 m. Several
works proposed numerical simulations that assert the feasibility of employing
LAN cables for indoor FH applications up to several hundreds of MHz, but an
A-MIMO-RoC experimental evaluation is still missing. Here, we present some
preliminary results obtained with an A-MIMO-RoC prototype made by low-cost
all-analog/all-passive devices along the signal path. This setup demonstrates
experimentally the feasibility of the proposed analog relaying of MIMO RF
signals over LAN cables up to 400 MHz, thus enabling an efficient exploitation
of the LAN cables transport capabilities for 5G indoor applications.Comment: Part of this work has been accepted as a conference publication to
ISWCS 201
Temperature- and Field Dependent Characterization of a Twisted Stacked-Tape Cable
The Twisted Stacked-Tape Cable (TSTC) is one of the major high temperature
superconductor cable concepts combining scalability, ease of fabrication and
high current density making it a possible candidate as conductor for large
scale magnets. To simulate the boundary conditions of such a magnets as well as
the temperature dependence of Twisted Stacked-Tape Cables a 1.16 m long sample
consisting of 40, 4 mm wide SuperPower REBCO tapes is characterized using the
"FBI" (force - field - current) superconductor test facility of the Institute
for Technical Physics (ITEP) of the Karlsruhe Institute of Technology (KIT). In
a first step, the magnetic background field is cycled while measuring the
current carrying capabilities to determine the impact of Lorentz forces on the
TSTC sample performance. In the first field cycle, the critical current of the
TSTC sample is tested up to 12 T. A significant Lorentz force of up to 65.6
kN/m at the maximal magnetic background field of 12 T result in a 11.8 %
irreversible degradation of the current carrying capabilities. The degradation
saturates (critical cable current of 5.46 kA at 4.2 K and 12 T background
field) and does not increase in following field cycles. In a second step, the
sample is characterized at different background fields (4-12 T) and surface
temperatures (4.2-37.8 K) utilizing the variable temperature insert of the
"FBI" test facility. In a third step, the performance along the length of the
sample is determined at 77 K, self-field. A 15 % degradation is obtained for
the central part of the sample which was within the high field region of the
magnet during the in-field measurements
Addressable time division multiplexer system /cable and connector study/ Final report
Reliability studies of single interrogation and single data cables used in prototype addressable time division multiplexer syste
Radiated emissions and experimental precautions of equipment with cables in GTEM cells
Any electric or electronic equipment sold within the European Union has to comply with the EC Directive on Electromagnetic Compatibility (EMC). To achieve compliance, the equipment must be tested for radiated/conducted emissions and immunity. A wide range of national and international testing methods and standards are in force such as the IEC 61000-40-20. However, standards in general lack of describing testing methods for equipment with cables. Since most devices and systems contain leads and cables; the current standards cannot be directly employed. In an effort to approach this crucial matter, we present the outcomes of measurements conducted on an EUT (metal box) with different cable bundle configurations, in conjunction with both, the correlation algorithm given in the standards and the repeatability concerns between different GTEM cell
Simple Front End Electronics for Multigap Resistive Plate Chambers
A simple circuit for the presentation of the signals from Multi-gap Resistive
Plate Chambers (MRPCs) to standard existing digitization electronics is
described. The circuit is based on "off-the-shelf" discrete components. An
optimization of the values of specific components is required to match the
aspects of the MRPCs for the given application. This simple circuit is an
attractive option for the initial signal processing for MRPC prototyping and
bench- or beam-testing efforts, as well as for final implementations of
small-area Time-of-Flight systems with existing data acquisition systems.Comment: submitted to Nucl. Inst. and Methods, Section
Industrial Fieldbus Improvements in Power Distribution and Conducted Noise Immunity With No Extra Costs
Industrial distributed control continues the move
toward networks at all levels. At lower levels, control networks
provide flexibility, reliability, and low cost, although perhaps the
simplest but most important advantage is the reduced volume
of wiring. Powered fieldbuses offer particular notable benefits in
system wiring simplification. Nevertheless, very few papers are
dealing with the potentials and limitations in power distribution
through the bus cable. Only a few of the existent fieldbus standards
consider this possibility but often simply as an option without
enough technical specifications. In fact, nobody talks about it, but
power distribution through the bus and conducted noise disturbances
are strongly related. This paper points out and analyzes
these limitations and proposes a new low-cost fieldbus physical
layer that enlarges power distribution capability of the bus and
improves system robustness. We show an industrial application
on water desalination plants and the very good results obtained
owing to the fieldbus. Finally, we present electromagnetic compatibility
test results that verify improvements against electrical fast
transients on the sensor/actuator connection side as disturbances
usually encountered in harsh-environment industrial applications
The IceCube Neutrino Observatory: Instrumentation and Online Systems
The IceCube Neutrino Observatory is a cubic-kilometer-scale high-energy
neutrino detector built into the ice at the South Pole. Construction of
IceCube, the largest neutrino detector built to date, was completed in 2011 and
enabled the discovery of high-energy astrophysical neutrinos. We describe here
the design, production, and calibration of the IceCube digital optical module
(DOM), the cable systems, computing hardware, and our methodology for drilling
and deployment. We also describe the online triggering and data filtering
systems that select candidate neutrino and cosmic ray events for analysis. Due
to a rigorous pre-deployment protocol, 98.4% of the DOMs in the deep ice are
operating and collecting data. IceCube routinely achieves a detector uptime of
99% by emphasizing software stability and monitoring. Detector operations have
been stable since construction was completed, and the detector is expected to
operate at least until the end of the next decade.Comment: 83 pages, 50 figures; updated with minor changes from journal review
and proofin
Track Extrapolation and Distribution for the CDF-II Trigger System
The CDF-II experiment is a multipurpose detector designed to study a wide
range of processes observed in the high energy proton-antiproton collisions
produced by the Fermilab Tevatron. With event rates greater than 1MHz, the
CDF-II trigger system is crucial for selecting interesting events for
subsequent analysis. This document provides an overview of the Track
Extrapolation System (XTRP), a component of the CDF-II trigger system. The XTRP
is a fully digital system that is utilized in the track-based selection of high
momentum lepton and heavy flavor signatures. The design of the XTRP system
includes five different custom boards utilizing discrete and FPGA technology
residing in a single VME crate. We describe the design, construction,
commissioning and operation of this system.Comment: 34 pages, 9 figures, submitted to Nucl.Inst.Meth.
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