Wyniki wyszukiwania - BazTech

1

A low cost EMC pre-compliance board for electronic devices and smart grids networks

Araujo H. X., Melo M. D. B., Casella I. R. S., Capovilla C. E.

Przegląd Elektrotechniczny

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2017

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R. 93, nr 3

284--286

EN

In this work, a low cost EMC – Electromagnetic Compatibility pre-compliance board, based on the conducted emission technique, is proposed as an option to analyze electronic devices used in telecommunications and smart grid network enviroments. In general, as the IC is the major responsible of unintentional emissions and coupling, some specific pre-compliance setup tests are employed to analyze these detrimental effects to the system as a whole. Therefore, an EMC Pre-Compliance Board was designed and built to operate from 150 KHz to 30 MHz. Simulated and experimental results are compared to validate the test setup.

PL

W pracy przedstawiono prosty układ umożliwiający testowanie i poprawę elektrokompatybilności urządzeń telekomunikacyjnych I wyposażenia sieci smart grid. Układ pracuje w zakresie częstotliwości 150 kHz – 30 MHz.

2

A novel methodology for signal recovery in linear time invariant system for medicine applications

Melo M. D. B., Araujo H. X., Da Rocha F.

Przegląd Elektrotechniczny

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2016

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R. 92, nr 10

199--203

EN

This paper presents a deconvolution based method that allows the improvement of the time response of a Swan-Ganz catheter. The goal of the deconvolution method is to obtain the input signal of an LTI system from the knowledge of its output and its impulse response. The noise causes degradation of the recovered signal, and this phenomenon is also discussed. The deconvolved signal is enriched in function of the cutoff frequency of the filter. It is shown that as the cutoff frequency increases, the deconvolved signal becomes more nosier. A Butterworth digital filter of third order, multiplied by the reverse impulse response was used in the frequency domain, and the response in frequency for the 1/H(s) function, limited for the various cutoff frequency of the filter are shown. It can be clearly observed that for higher cutoff frequency magnitude, the signal becomes completely distorted. Experiments with animals were used to measure the impulse response and the obtained results were satisfactory, with average error of 8.9%. The results suggest that the method can be useful in applications of linear systems.

PL

Opisano metodę poprawy odpowiedzi czasowej cewnika typu Swan_ganz bazująca na rozplocie. Umożlia to ocenę sygnału wejściowego na podstawie odpowiedzi układu I znajomosci odpowiedzi impulsowej. . W pracy analizowano wpływ filtru cyfrowego na parametry sygnału. Metode z dobrym rezultatem przetestowano na zwierzętach.

3

A Modified Ultra Wide Band Antenna With Metamaterial Patterns for Telecommunications Systems

Guelber E. F., Cardoso A. S. V., Capovilla C. E., Araujo H. X.

Przegląd Elektrotechniczny

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2016

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R. 92, nr 1

166--169

EN

In this work, an ultra wide band antenna is modified with periodic structures in order to improve its performance, in terms of gain, bandwidth and resonance. Basically, three topologies are used (Jerusalem cross pair, fractal and tripolar array).The main idea is improve its performance without increase its dimensions which could compromise their application in telecommunications systems especially mobile devices.

PL

W artykule zaprezentowano projekt ultra szerokopasmowej anteny z periodyczną strukturą w celu optymalizacji wzmocnienia, pasma I rezonansu. Testowano trzy topologie – para krzyży Jeruzalem, struktura fraktalna i układ trzybiegunowy.

4

An Integrated Analog Demultiplexer for Spatial Multiplexing of Local Elements Scheme Using MOS Transistors

Capovilla C. E., Araujo H. X., Kretly L. C.

Przegląd Elektrotechniczny

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2014

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R. 90, nr 3

115--118

EN

This paper proposes a CMOS analog demultiplexer for Spatial Multiplexing of Local Elements scheme at baseband level. This technique is a front-end receiver architecture which uses only one RF channel, carrying multiplexed information from multiple antennas into one RF single channel. The described circuit has four channels, in which each channel has a differential switch pair and an OTA for amplification and differential to single-ended signal conversion. The specifications and simulation performance are in close agreement, which validate the proposed compact design.

PL

W artykule zaprezentowano analogowy demultiplekser CMOS do przestrzennego multipleksowania (Spatial multiplexing). Ta technika jest stosowana w odbiornikach używających tylko jeden kanał RF i umożliwia multipleksowanie informacji z wielu anten. Opisany układ ma cztery kanały i każdy z kanałów ma różną parę kluczy.

5

Experimental Analysis of Quasi-Yagi Antenna Shapes

Capovilla C. E., Araujo H. X., Filho A. J. S., Kretly L. C.

Przegląd Elektrotechniczny

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2013

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R. 89, nr 12

100-104

EN

In this work, a broadband quasi-Yagi antenna is presented and its shape design is changed to analyse new characteristics and properties for wireless communications. This microstrip-fed antenna is designed in five different shape versions: dipole driver, patch driver, meander driver, log-periodic director array, and multi-director array. Details of the proposed designs and measured results of input return loss and radiation pattern are presented and discussed. In addition, a technique using a microwave link to measure the radiation pattern is explored, showing good radiation characteristic of the elements in a real environment.

PL

Przedstawiono analizę i projekt nowej anteny szerokopasmowej typu Yagi przeznaczonej do komunikacji bezprzewodowej. Antenę zaprojektowano w pięciu różnych wersjach kształtu. Przedstawiono wyniki badań tych propozycji.