DocumentCode :
1495130
Title :
On the SFDR Upperbound in DDFS Utilizing Polynomial Interpolation Methods
Author :
Ashrafi, Ashkan
Author_Institution :
Dept. of Electr. & Comput. Eng., San Diego State Univ., San Diego, CA, USA
Volume :
59
Issue :
5
fYear :
2012
fDate :
5/1/2012 12:00:00 AM
Firstpage :
307
Lastpage :
311
Abstract :
In this brief, the theoretical analysis that obtains the upperbound of the spurious free dynamic range (SFDR) of the direct digital frequency synthesizers (DDFSs) with phase-to-sine mapper (PSM) structured by polynomial interpolation is revisited. A complete analysis of the SFDR upperbound of these DDFS architectures was provided by Ashrafi and Adhami in 2007, where the authors formulated the SFDR upperbound as the Chebyshev minimax solution to an overdetermined system of linear equations. However, some issues in finding the Chebyshev minimax solution were not made clear in that paper regarding the minimax error at the fundamental harmonic of the output sinusoid. These issues, along with the erroneous behavior of numerical computation packages used for solving the Chebyshev minimax problem, misled Chau and Chen to claim that the results of the aforementioned paper were wrong. This brief clarifies the issues with the original paper, exhibits the problems with some of the available numerical computation packages, and refutes the claims that Chau and Chen made.
Keywords :
direct digital synthesis; interpolation; minimax techniques; Chebyshev minimax solution; DDFS; SFDR upperbound; direct digital frequency synthesizers; linear equations; minimax error; numerical computation packages; phase-to-sine mapper; polynomial interpolation methods; spurious free dynamic range; theoretical analysis; Chebyshev approximation; Frequency synthesizers; Harmonic analysis; Interpolation; Polynomials; Vectors; Chebyshev minimax approximation; direct digital frequency synthesizers (DDFSs); spurious free dynamic range (SFDR);
fLanguage :
English
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
Publisher :
ieee
ISSN :
1549-7747
Type :
jour
DOI :
10.1109/TCSII.2012.2190861
Filename :
6183503
Link To Document :
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