Kurt Edward Rasmussen

US Patent:

52028461, Apr 13, 1993

Filed:

Dec 19, 1990

Appl. No.:

7/632248

Inventors:

Kurt E. Rasmussen - Torrance CA
Tom C. Bryan - Redondo Beach CA

Assignee:

Hughes Aircraft Company - Los Angeles CA

International Classification:

G06F 102

US Classification:

364721

Abstract:

A variable frequency synthesizer including a modulo N counter having a count limit N that is a product of prime numbers and responsive to a digital control word for providing a digital ramp signal representative of the phase of a sinewave, an inversion circuit responsive to the digital ramp signal for producing a digital triangular signal having a frequency determined by the control word, and conversion means for converting the digital triangular signal to an analog triangular signal. Selecting the count limit N as a product of prime numbers substantially reduces spurious distortion due to time step quantization of the digital ramp signal.