A direct digital synthesizer of compound wideband signals

Ryabov, I. V.; Tolmachev, S. V.; Chernov, D A

doi:10.1134/s0020441214040095

Cited by 4 publications

(4 citation statements)

References 2 publications

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“…When traditional DDS realizes frequency synthesis, the frequency tuning word input to the phase accumulator is accumulated in turn under the system clock, and the instantaneous value of the waveform is synthesized by means of lookup table [10], [15]. As shown in Fig.2, the method produces a time series of digital words at the output of the accumulator that increases linearly until the accumulator rolls over at its maximum value of 2 C .…”

Section: Dds Spurious Anlysismentioning

confidence: 99%

“…In the process of frequency synthesis, the phase of waveform signal is obtained by digital phase accumulation, and the phase amplitude is converted. Compared with the traditional frequency synthesis technology, DDS has the advantages of short frequency conversion time, high frequency resolution, easy integration, high reliability and easy debugging [7]- [10]. With the continuous improvement of DDS technology, its application fields are more and more extensive, such as aerospace, surveying and mapping, guidance, satellite positioning and high-speed communications and other high-tech fields, just as shown in Fig.1 [11]- [14].…”

Section: Introductionmentioning

confidence: 99%

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A Suppressing Method for Spur Caused by Amplitude Quantization in DDS

Tang

Hou

2019

IEEE Access

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Direct digital synthesis (DDS) technology is widely used in navigation, communications, aerospace, and other fields. Due to the technical limitations in the process of DDS digitization, the output spectrum of DDS is inevitably spurious. In order to meet the requirement of the pure frequency reference signal for modern instrument or equipment, it is necessary to correctly analyze the spur of DDS and effectively suppress it. In this paper, the causes of the spur in traditional DDS are analyzed, and a piecewise linear approximation method is proposed to suppress the amplitude quantization spur of DDS. In order to verify the effectiveness of the proposed spurious suppression method in this paper, the MATLAB simulation is carried out and a field programmable gate array (FPGA) hardware platform for DDS is developed. The simulation and actual test results prove the feasibility of this method. In the limited storage space, this method improves the accuracy of amplitude quantization, reduces spurs, and enhances the accuracy of synthetic frequency.

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Section: Dds Spurious Anlysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A Suppressing Method for Spur Caused by Amplitude Quantization in DDS

Tang

Hou

2019

IEEE Access

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“…The accumulator output sequence range 0 to (2 P − 1) maps to one revolution on the unit circle, that is, it linearly maps binary values from 0 to (2 P − 1) to radian angles from 0 to 2π. This mapping arrangement allows the angle-to-amplitude converter to translate the P-bits words to Y-bits amplitude values (Y) in a very efficient manner, and finally a low-pass filter is used to obtain a desired sinusoidal signal [17]. angle-to-amplitude converter to translate the P-bits words to Y-bits amplitude values (Y) in a very efficient manner, and finally a low-pass filter is used to obtain a desired sinusoidal signal [17].…”

Section: Defects Of Traditional Ddsmentioning

confidence: 99%

“…This mapping arrangement allows the angle-to-amplitude converter to translate the P-bits words to Y-bits amplitude values (Y) in a very efficient manner, and finally a low-pass filter is used to obtain a desired sinusoidal signal [17]. angle-to-amplitude converter to translate the P-bits words to Y-bits amplitude values (Y) in a very efficient manner, and finally a low-pass filter is used to obtain a desired sinusoidal signal [17]. The Y-bits digital amplitude sequence signal output by the converter is converted into an analog signal by a Y-bit DAC (Digital to Analog Converter, DAC) chip, and finally a low-pass filter is used to obtain a desired sinusoidal signal.…”

Section: Defects Of Traditional Ddsmentioning

confidence: 99%

An Accurate DDS Method Using Compound Frequency Tuning Word and Its FPGA Implementation

Yuqing

Tang

2018

Electronics

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Because of its high resolution, low cost, small volume, low power dissipation and less conversion time consumption, the direct digital synthesizer (DDS) method has been applied more and more in the fields of frequency synthesis and signal generation. However, only a limited number of precise frequency signals can be synthesized by the traditional DDS, for the reason that its accumulator modulus is fixed, and its frequency tuning word must be integer. In this paper, a precise DDS method using compound frequency tuning word is proposed, which improves the accuracy of synthesized signals at any frequency points on the premise of guaranteeing the stability of synthesized signals. In order to verify the effectiveness of the new method, a DDS frequency synthesizer based on FPGA is designed and implemented. Taking the rubidium atomic clock PRS10 as standard frequency source, the experiments shows that the frequency stability of the synthesized signal is better than 8.0 × 10−12/s, the relative frequency error is less than 4.8 × 10−12, and that the frequency accuracy is improved by three orders of magnitude compared with the traditional DDS method.

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