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Model konwersji A/C oraz demodulator IQ dla radaru z cyfrowym formowaniem wiązki

Nitecki D.

Elektronika : konstrukcje, technologie, zastosowania

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2013

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Vol. 54, nr 3

56-60

PL

W artykule omówiono zagadnienia dotyczące parametrów wielokanałowej konwersji analogowo-cyfrowej oraz cyfrowego demodulatora IQ. Przedstawiono cele prac modelowych z modułem konwersji A/C wraz z opisem ich realizacji. Opisano definicję i sposoby pomiaru parametrów konwersji analogowo-cyfrowej tj.: SFDR, SINAD, ENOB, THD oraz przesłuch międzykanałowy. Omówiono cyfrową demodulację IQ. Przedstawiono warunki pracy radaru oraz związane z nimi wymogi jakie muszą spełnić poszczególne etapy demodulacji. Opisano implementację cyfrowej demodulacji IQ w architekturze układu FPGA.

EN

This work concerns the necessary measures of the multi-channel ADC dynamic performance before the implementation of ADC module. It also presents the implmentation of the digital IQ demodulator in the FPGA device. Project based on the FPGA device allows to create multi-channel and fully-parallel systems. In addition one large FPGA devices allows to implement e.g. All digital IQ demodulation tracks in all receiving channels of the radar station. The system consists of FPGA also allows the designer to test the behavior of one component independenity of the others, which has a significant impact on ensuring the high reliability of the designed system.

2

DAC testing using impulse signals

Vedral J., Fexa P.

Metrology and Measurement Systems

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2012

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Vol. 19, nr 1

105-114

EN

The Multi-Tone (MT) signal with uniform amplitudes can be used for DAC testing. This paper shows an easier way to generate a MT signal using several impulse signals. The article also analyzes qualities of methods for testing the dynamic parameters of Digital to Analog Converters using an impulse signal. The MT, Damped Sine Wave (DSW) and Sinx/x (SINC) signals will be used as the source for these tests. The Effective Number of Bits (ENOB) and Signal to noise and distortion (SINAD) are evaluated in the frequency domain and they are modified using the Crest Factor (CF) correction and compared with the standard results of the Sine Wave FFT test. The first advantage of the test using an impulse signal is that you need fewer input parameters to create the band signal for testing the DAC. The second one is to reduce the testing time using a band signal in comparison with multiple tests using a single sine wave.

3

DAC testing using modulated signals

Fexa P., Verdal J., Svatoš J.

Metrology and Measurement Systems

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2011

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Vol. 18, nr 2

283-293

EN

This document analyses qualities of methods used for testing dynamical parameters of Digital-to-Analog Converters (DAC) using a multi-frequency signal. As the source for these signals, Amplitude Modulated (AM) and Frequency Modulated (FM) signals are used. These signals are often used in radio engineering. Results of the tests, like Effective Number of Bits (ENOB), Signal-to-Noise and Distortion (SINAD), are evaluated in the frequency domain and they are compared with standard results of Sine Wave FFT test methods. The aim of this research is firstly to test whether it is possible to test a DAC using modulated signals, secondly to reduce testing time, while estimating band performance of DAC.