A direct-digital synthesizer with improved spectral performance

Author

O´Leary, Paul ; Maloberti, Franco

Author_Institution

Joanneum Res., Graz, Austria

Volume

39

Issue

7

fYear

1991

fDate

7/1/1991 12:00:00 AM

Firstpage

1046

Lastpage

1048

Abstract

The authors present a modified direct-digital synthesizer which uses noise shaping to reduce the effects of phase-accumulator truncation on the output spectrum. The discrete spectral disturbances associated with this truncation error are strongly reduced with the proposed method, making the synthesizer suitable for high-performance signal processing. The proposed architecture uses first-order noise shaping. Higher order noise shaping can also be used if required. The modified circuit offers considerable improvement in the synthesizer performance when the generated frequency is low with respect to the clock frequency

Keywords

digital circuits; frequency synthesizers; signal synthesis; clock frequency; direct-digital synthesizer; discrete spectral disturbances; generated frequency; noise shaping; output spectrum; phase-accumulator truncation; signal processing; spectral performance; truncation error; Circuits; Finite wordlength effects; Frequency synthesizers; Noise shaping; Phase modulation; Phase noise; Quantization; Read only memory; Signal processing; Signal synthesis;

fLanguage

English

Journal_Title

Communications, IEEE Transactions on

Publisher

ieee

ISSN

0090-6778

Type

jour

DOI

10.1109/26.87209

Filename

87209