Open AccessA Numerically Controlled Oscillator with a Fine Phase Tuner and a Rounding Processor
Author(s) -
Lim InGi,
Kim WhanWoo
Publication year - 2004
Publication title -
etri journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 46
eISSN - 2233-7326
pISSN - 1225-6463
DOI - 10.4218/etrij.04.0204.0026
Subject(s) - rounding , waveform , tuner , sine wave , phase (matter) , phase noise , adder , electronic engineering , control theory (sociology) , mathematics , physics , computer science , engineering , electrical engineering , telecommunications , radio frequency , voltage , control (management) , quantum mechanics , artificial intelligence , operating system , cmos
We propose a fine phase tuner and a rounding processor for a numerically controlled oscillator (NCO), yielding a reduced phase error in generating a digital sine waveform. By using the fine phase tuner presented in this paper, when the ratio of the desired sine wave frequency to the clock frequency is expressed as a fraction, an accurate adjustment in representing the fractional value can be achieved with simple hardware. In addition, the proposed rounding processor reduces the effects of phase truncation on the output spectrum. Logic simulation results of the NCO using these techniques show that the noise spectrum and mean square error (MSE) for eight output bits of a 3.125 MHz sine waveform are reduced by 8.68 dB and 5.5 dB, respectively, compared to those of the truncation method, and 2.38 dB and 0.83 dB, respectively, compared to those of Paul's scheme.