Wyniki wyszukiwania - BazTech

1

Wideband Nine-Port Reflectometer

Odrobina S., Staszek K., Wincza K., Gruszczynski S.

International Journal of Electronics and Telecommunications

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2018

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Vol. 64, No. 1

19--25

EN

The paper presents a wideband nine-port reflectometer realized as a cascade connection of six- and five-port reflectometers. It is shown that such a solution allows for a convenient adjustment of circuits’ parameters in order to provide significantly reduced measurement uncertainty with respect to other reported reflectometers. Simultaneously, the proposed network features a simple and flexible design. For the experimental verification, the proposed nine-port reflectometer has been manufactured and incorporated into the system intended for reflection coefficient measurements within the frequency range 2.5 - 3.5 GHz. The obtained results are in an excellent agreement with the values measured using a commercial VNA.

2

Opis i implementacja algorytmu wyznaczania rozkładu fazy obrazów prążkowych w układzie FPGA

Staszek K.

Pomiary Automatyka Kontrola

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2012

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R. 58, nr 3

298-301

PL

Niniejszy artykuł przedstawia opis algorytmu wyznaczania rozkładu fazy z obrazów prążkowych. Jest to jeden z kroków przetwarzania obrazów stosowanych powszechnie w profilometrii optycznej, dzięki której na podstawie zdjęcia można odtworzyć trójwymiarowy kształt obiektu. Algorytm oparty został na zespolonej transformacji falkowej i pozwala na pełną automatyzację procesu skanowania. Duży nacisk został położony na optymalizację pod kątem sprzętowej implementacji w układzie FPGA. Wykazana została dobra odporność zarówno na szumy jak i niską jakość obrazu prążkowego.

EN

This paper presents a phase extraction algorithm used in fringe pattern analysis. It is one of steps in optical profilometry process used to obtain full three-dimensional information about the measured object shape. The algorithm is based on the complex wavelet transform and allows full automation of the process. Since the fringe patterns represent non-stationary signals, application of time-frequency analysis provides better results than the commonly used Fourier transform. Six variants of the wavelet transform (one- and two-dimensional) were simulated in order to minimise the required hardware resources in FPGA and test their robustness. As a result the one-dimensional minimised transform of variable size was chosen. A further part of the paper is focused on particular blocks of implementation. The presented wavelet coefficient computational method decreases the number of necessary operations during transform computing and enables significant reducing of memory requirements. The applied arcus tangens block with logarithmic division of approximation intervals gives correct extracted phase values in the entire four-quarter interval. The solution mentioned above leads to great minimisation of the described block without any impact on the accuracy. The last part of the paper presents processing results. The emphasis was put on the noise robustness and influence of the fringe pattern poor quality on the processing error. As it is shown, the algorithm works correctly even with only three gray levels and high noise level present in the input picture.

3

Compact Broadband Rat-Race Coupler in Multilayer Technology Designed with the Use of Artificial Right- and Left-Handed Transmission Lines

Staszek K., Kołodziej J., Wilcza K., Gruszczyński S.

Journal of Telecommunications and Information Technology

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2012

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nr 2

107-112

EN

The paper presents a compact broadband rat-race coupler for the first time designed and realized in a mul- tilayer microstrip technology. To achieve both broad operational bandwidth and a compact size the 270? transmission line of a conventional rat-race, coupler has been replaced by a -90? left-handed transmission line realized with the use of a quasi-lumped element technique. Moreover, to achieve better compactness of the resulting coupler, all 90? right-handed transmission lines have been realized with the use of the same technique. It has been also proved that simple LC approximation of a left-handed transmission line can be successfully used for the design. Moreover, it has been shown that when appropriately chosen, the multilayer dielectric structure allows for realization of structures designed with the use of this simple approximation, for both right-handed and left-handed transmission lines, without loosing too much of a performance.