Efficient Digital Synthesis of Waveforms Based on Periodic Functions

Reference #:

2004-231

Inventors/Contributors

Jonathan D. Coker, Robert A. Kertis

Description

The present invention details a substantial implementation improvement for a broad class of Direct Digital Synthesizers (DDSs). A DDS synthesizes a predetermined waveform via digital (i.e., sampled) methods. Typically, the output waveforms are based on sinusoidal functions. For example, a DDS may generate sine waves of various frequency (under digital control). Chirp waveforms (which are sinusoids of continuously varying instantaneous frequency) are another common example. The present invention describes improved methods for the digital generation of the phase argument to a periodic function based on a modular Chinese Remainder Theorem representation. This representation has particularly advantageous qualities in a ramped-frequency implementation. The present invention also describes an efficient method to factor the digital-phase-to-analog-voltage function into small digital-to-analog converters when the periodic waveform is a sinusoid.

Patent Status

Pending