Wyniki wyszukiwania - BazTech

1

ANSDM converters dynamic range design process

Golański Ryszard, Godek Juliusz

Science, Technology and Innovation

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2020

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Vol. 10, no. 3

1--7

EN

The results of analytic and simulating works proved that for nonstationary sources, the delta converters with adaptive sampling expose higher coding efficiency than the former proposals, based on uniform sampling methods. The knowledge of the sampling interval range and the algorithm of the Nonuniform Sampling Delta Modulation and Adaptive Nonuniform Sampling Delta Modulation allows finding the necessary number of the sampling intervals and their values that maximizes SNR. The total dynamic range of the ANSDM modulator is the product of the dynamic range both from sampling interval and step size adaptation. Due to the high complexity of the calculations, the ANSDMsoft program was developed to support computing. All computational works were carried out using the Maple environment. Maple allows to solve complex mathematical functions and display their results in a simple way. Most importantly, it supports the LambertW function, used in the computing of NSDM or ANSDM modulators parameters. Graphic illustrations of the NSDM and ANSDM modulator dynamic range as a function of the minimum and maximum sampling frequency are presented.

2

Szerokopasmowa akwizycja sygnałów w systemach ELINT

Hibner R., Zieliński R. J.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2016

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nr 8-9

1089--1092, CD

PL

Rosnące wymagania stawiane systemom rozpoznania (ELINT) wymuszają zwiększanie pasma analizy z zachowaniem wysokiej dynamiki detekcji sygnałów. W artykule została przedstawiona analiza możliwych rozwiązań. Przestawione zostały również wyniki pomiarów sprzętowej implementacji szerokopasmowego systemu akwizycji opartego o równoległe kanały, z której wynika, że możliwe jest uzyskanie dynamiki przekraczającej 70dB w dowolnie szerokim paśmie analizy przy zastosowaniu równoległej struktury.

EN

Growing expectations for ELINT systems’ parameters lead to expansion of analysis bandwidth with high dynamic range requirements. This article presents an analysis of possible solutions of wideband acquisition systems. Additionally, experimental results of hardware implemented multichannel system are presented. Dynamic range exceeding 70dB was achieved in parallel architecture that allows unlimited bandwidth scalability.

3

FPGA Implementation of a Numerically Controlled Oscillator with Spur Reduction

Lachowicz S., Pfleiderer H-J.

Electronics and Telecommunications Quarterly

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2009

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Vol. 55, No 4

617-624

EN

This paper presents a novel method of reducing the spurious signal content in a digitally synthesized sine wave at the output of a numerically controlled oscillator (NCO). The proposed method uses a linear approximation subsystem with a reduced size look-up table (LUT). Two NCO architectures are considered. Architecture 0 - which is the standard -in which the accumulator word length is longer than the LUT address word, is compared with Architecture 1, where the accumulator bits beyond the LUT address space are used for the linear approximation of the value in between the entries of the LUT. Analysis of both architectures demonstrates that the spurious free dynamic range (SFDR) in Architecture 1 equates to 12 dBc per bit of the address space of the LUT as opposed to 6 dBc for Architecture 0. The system was implemented and tested using the Xilinx Spartan 3 platform.

4

Wielofazowy generator przebiegów poliharmonicznych

Jakubski B.

Pomiary Automatyka Kontrola

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2006

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R. 52, nr 6 bis

112-114

PL

W artykule zaprezentowano strukturę trójfazowego kalibratora mocy ze wskazaniem miejsca i roli generatora wielofazowego i wpływu jego parametrów na parametry kalibratora mocy. Opisano struktury wielofazowego generatora analogowego i cyfrowego. Następnie przedstawiono strukturę i podstawowe parametry wielofazowego generatora cyfrowego zaprojektowanego do kalibratora mocy C300 oraz ujawniono związek pomiędzy rozdzielczością nastaw kąta fazowego a zniekształceniami przebiegu wyjściowego generatora.

EN

In this paper was described structure of three-phase power calibrator with paying attention to multiphase generator. Generator parameters that influence on power calibrator properties was shown. Structure of analog and digital multiphase generator was described. Then was shown structure of multiphase generator that was designed for power calibrator C300 and harmonic distortion dependence on angle resolution.