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:
Feb. 19, 1991
Filed:
May. 25, 1990
Larry P Hobbs, Brentwood, CA (US);
Systron Donner, Concord, CA (US);
Abstract
A DSB-SC signal is demodulated using an up/down counter, the count direction of which is alternately switched in synchronism with the polarity of a reference carrier signal for the DSB-SC signal. The converter includes an integrator, a comparator and a charge-rebalancing current source to reset the integrator. Correction of the court value of the up/down counter is obtained by tracking and storing a partial-bit analog signal. The partial-bit analog signal corresponds to and is obtained from the output of the integrator just prior to the pahse transition of the reference carrier signal. A capacitor samples the partial-bit analog signal information and subsequently transfers that information to the integrator input. The transfer of a charge of twice the magnitude and opposite polarity to the integrator compensates for the partial bit analog signal as it is detected by the up/down counter. A digital system for converting the partial-bit analog signal to a binary code word is provided. A number of these binary code words are summed and when the resultant sum exceeds a certain value a correction count for the up/down counter is provided to increment the up/down counter.