The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 12, 1994
Filed:
Jul. 17, 1992
Dwight D Poplin, Salem, OR (US);
II Morrow Inc., Salem, OR (US);
Abstract
A numerically-controlled modulated oscillator and modulation method which selectively provides frequency modulation, phase modulation or amplitude modulation with minimal circuitry. A numerically-controlled modulated oscillator is provided having a tuning register for receiving a center frequency parameter, an adder for receiving at one input the frequency parameter, a phase accumulator for receiving a phase increment number from the adder and producing a waveform phase number, a waveform memory for producing a waveform amplitude number in response to the phase number, and a digital-to-analog converter for producing an analog signal in response to the waveform amplitude number. Another input is provided to the adder from an angle modulation register which provides an angle modulation parameter. This parameter can perform either phase or frequency modulation. In the case of frequency modulation, the angle modulation represents the current amplitude of the modulation signal and is added to the center frequency parameter on every clock cycle. In the case of phase modulation, the angle modulation parameter is provided at a periodic rate and then for only one clock cycle. In this case, the value of the angle modulation parameter is relative to the previous angle modulation parameter. Amplitude modulation is provided by an amplitude modulation register which receives an amplitude modulation parameter and applies it to a multiplier disposed between the waveform memory and the digital-to-analog converter.