Title:
DIRECT DIGITAL SYNTHESIZER, OPTICAL MODULATOR, OPTICAL REFLECTOMETRY DEVICE, AND OPTICAL COMMUNICATION SYSTEM
Document Type and Number:
WIPO Patent Application WO/2012/036157
Kind Code:
A1
Abstract:
A DDS (100) is provided with: accumulating unit (110), a phase adding unit (120), a phase-amplitude converting unit (130), etc. The accumulating unit (110) accumulates frequency command values (p) at timings at which a reference clock (clock) issues instructions at a constant frequency, and outputs the accumulation value. The phase adding unit (120) adds a phase offset value (q) to the accumulation value, and outputs the addition value (R). The phase-amplitude converting unit (130) assumes the addition value (R) as a phase value and outputs a digital amplitude value corresponding to a remainder (r) obtained by dividing the phase value (R) by a value (M) among digital amplitude values of M waveform samples. The greatest common divisor of the frequency command values (p) and the number (M) of waveform samples is smaller than the frequency command values (p).
Inventors:
OHTSUKA TAKAFUMI (JP)
Application Number:
PCT/JP2011/070869
Publication Date:
March 22, 2012
Filing Date:
September 13, 2011
Export Citation:
Assignee:
SUMITOMO ELECTRIC INDUSTRIES (JP)
OHTSUKA TAKAFUMI (JP)
OHTSUKA TAKAFUMI (JP)
International Classes:
H03B28/00; G01M11/00
Foreign References:
| JP2003264431A | 2003-09-19 | |||
| JPH09127196A | 1997-05-16 | |||
| JPH0192821A | 1989-04-12 | |||
| JP2010139253A | 2010-06-24 | |||
| JP2010175502A | 2010-08-12 |
Attorney, Agent or Firm:
HASEGAWA Yoshiki et al. (JP)
Yoshiki Hasegawa (JP)
Yoshiki Hasegawa (JP)
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Claims: