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:
Oct. 11, 1988
Filed:
May. 01, 1987
Paul Hurst, Yolo, CA (US);
Kiyoshi Fukahori, Grass Valley, CA (US);
Silicon Systems Inc., Tustin, CA (US);
Abstract
A switched capacitor circuit implements a base band, finite impulse response filter (BBF) and balanced modulator with a single operational amplifier. The analog modulator has particular application in voice band modem applications and requires little or no microprocessor code space. Simplified sine and cosine functions are implemented in a pair of base band filters such that the output of only one base band filter is required at any one time. In this manner, a single operational amplifier may be utilized to implement the analog modulator/base band filter of the present invention. The use of switched capacitor technology and a single operational amplifier results in less silicon area dedicated to the analog modulator than for corresponding digital modulators.