Giovanni Betta, Domenico Capriglione, Carlo Carobbi, Marco Donald Migliore
The accurate knowledge of the antenna factor is a fundamental requirement for reliable electromagnetic compatibility (EMC) measurements in emissions, immunity and human exposure tests. According to international standards, this would imply calibrating antennas in close-to-ideal test sites (calibration test sites), characterized by very large sizes of the ground plane and of the empty space volume above it (free-space behaviour). On the other hand the greater number of EMC test sites is designed for measurements at 3 meters distance, therefore it would be very convenient to calibrate antennas...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Catalin Damian, Cristian Zet, Cristian Fosalau
In the paper, an instrument for simultaneous measurement of active, reactive and apparent power is presented. Its functionality is based on a PWM intermediary conversion multichannel analog to digital converter (ADC). The instrument is implemented on an Altera’s Flex10k70 Field Programmable Gate Array (FPGA) device for single phase. It fits roughly 60% of logic cells without any resource sharing algorithm. All the operations are executed in a parallel mode, providing a very short execution time.
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Massimiliano Annoni, Marco Faifer, Loredana Cristaldi, Michele Norgia
The topic of water jet orifices efficiency and effectiveness evaluation has been considered in this paper. The performed analysis is based on the evaluation of the discharge, velocity and contraction coefficients for different water orifices. In order to overcome the difficulty to measure the water velocity at the orifice exit, which can reach 900 m/s in case of pure water jet applications (without abrasive additives), a suitable laser Doppler measurement system has been applied. An analysis of orifice performances is presented in the present paper, also considering the case of broken...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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M. Annoni, L. Cristaldi, M. Faifer
Water jet and Abrasive Water Jet (WJ/AWJ) are manufacturing technologies suitable for particular operations (cutting, milling, turning, surface treatment, etc.) on different types of materials. The use of water (or water mixed to abrasive in AWJ technology) allows working both soft and hard materials without damaging the interested area of the workpiece. In previous studies the authors have just shown how it is possible to detect wrong operating conditions or to foresee them for an AWJ system analyzing the instantaneous electric power signal measured at the supply section of the system....
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Nejmeddine Jouida, Chiheb Rebai, Adel Ghazel, Dominique Dallet
This paper presents the design of an image-reject continuous-time (CT) quadrature bandpass (QBP) %Delta;%Sigma; modulator using a tailored signal-transfer-function (STF) design. The quadrature delta-sigma noise shaping with polyphase filter implementations and strategic IF placement effectively improve image rejection internally. The Fifth-order CT QBP %Delta;%Sigma; modulator planned for WiMAX and Bluetooth standards, illustrates clearly the totally elimination of image generation and the correctly signal process. This led to remove the baseband filter and PGA at the price of a very...
P.Arpaia, G. Spiezia
A procedure for bottlenecks analysis of the PXI bus communications of an automatic measurement station is proposed. The experimental case study of the Fast Digital Integrator (FDI), a general purpose data acquisition and processing card developed at the European Organization for Nuclear Research (CERN), is illustrated.
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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A. Ageev, D. Macii, D. Petri
The communication latency between Wireless Sensor Network (WSN) nodes can significantly affect the performance of real-time monitoring applications, especially when multi-hop network topologies are used. In fact, the end-to-end network delays may hinder the collaboration between different devices, thus preventing the applicability of data fusion algorithms or limiting the accuracy of internode time synchronization. Unfortunately, performing a thorough characterization of such latencies is not an easy task because they may depend considerably on the overall network data traffic as well as on...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Cristian Zet, Olga Plopa,Cătălin Damian, Cristian Foşalău
Impedance spectroscopy play an important role in fundamental and applied electrochemistry and materials science. In a number of respects it is the method of choice for characterizing the electrical behavior of systems in which the overall system behavior is determined by a number of strongly coupled processes, each proceeding at a different frequency. The paper presents a virtual instrument and the associated hardware that allows to perform the impedance spectroscopy on an electrolytical cell. It is aimed for studying phenomena (charge transfer, difusion or electrode polarisation) that occur...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Federico Perini, Fabio Ghelfi
A methodology to reproduce slow variations of operative temperature of electronic devices, and to measure the induced effects on them, is presented. That method has been conceived in order to test and characterise the new receivers developed for the Italian SKA (Square Kilometre Array) demonstrator, based on the re-instrumentation of part of the Northern Cross radio telescope, located in Medicina (Italy). All the instruments of the measurement system are controlled by a PC (i.e. initialization, calibration and data acquisition). This way has been possible to obtain a new thermal...
Exploring New Frontiers of Instrumentation and Methods for Electrical and Electronic Measurements
· TC4
· 2008
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Germano Bianchi, Federico Perini, Claudio Bortolotti, Jader Monari, Stelio Montebugnoli, Mauro Roma
For the most part, so far radio astronomy observations have been performed in protected frequency bands, reserved by ITU for scientific purposes. This means that, ideally, only the amplified equivalent system noise is present at the end of the receiver chain (i.e. the ADC input). So, typically, only a few bits are necessary to describe the signal (VLBI signals are digitised with only 2 bits), but today astronomers, in order to get more sensitivity and to boldly observe where no one has observed before, would like to study the radio sky even outside the protected bands. In these cases, a lot...