Title :
A non-binary direct digital synthesizer with an extended phase accumulator
Author :
Nosaka, Hideyuki ; Yamaguchi, Yoshio ; Muraguchi, Masahiro
Author_Institution :
NTT Photonics Labs., Kanagawa, Japan
Abstract :
We describe a new direct digital synthesizer (DDS) in which output tuning resolution is flexibly controlled. The new DDS has an extended phase accumulator (EPA) controlled by two frequency control words; one determines the wave number within a single EPA operation cycle, and the other determines the length of the cycle. The EPA allows the DDS to provide jitter-free signals, the frequencies of which are given by arbitrary fractional expressions. (The denominator is fixed in conventional DDS that use normal phase accumulators.) Experimental results showed that the EPA worked well, allowing flexible output tuning resolution.
Keywords :
circuit tuning; direct digital synthesis; frequency control; interpolation; cycle length determination; direct digital synthesizer; extended phase accumulator; flexibly controlled output tuning; frequency control words; jitter-free signals; nonbinary DDS; output tuning resolution; phase interpolation DDS; wave number determination; Bandwidth; Clocks; Frequency; Interpolation; Read only memory; Signal resolution; Switches; Synthesizers; Timing; Tuning;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
