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:
Jun. 18, 1985
Filed:
Jul. 22, 1982
Michael E Larson, Fond du Lac, WI (US);
AMCA International Corp., Fond du Lac, WI (US);
Abstract
An electrical circuit and method for multiplying an analog input signal by a sinusoidal function having an instantaneous phase specified by a number signaled in binary format. As a sine wave generator, the binary number is supplied by a counter clocked at a multiple of the desired sine wave frequency. The most significant bit of the counter modulates the polarity of or actually constitutes the analog input signal which is then fed to a numerically-controlled attenuator driven by the less significant binary counter outputs. The attenuator has selectively switched resistors with values specifying a sine table of attenuation from 0 to 90 degrees. A particular resistor is selected by an analog multiplexer having paired complementary outputs so that over the range of less significant bit values, a full 180 degrees of the sinusoid is generated. As a sine wave modulator, the polarity of the analog input signal is modulated in a balanced modulator by the most significant bit of the counter, and the balanced modulator output is used as the input to the attenuator.