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:
Aug. 29, 2006
Filed:
Aug. 06, 2002
Saleh R. Al-araji, Alpharetta, GA (US);
John Skrobko, Berkeley Lake, GA (US);
Saleh R. Al-Araji, Alpharetta, GA (US);
John Skrobko, Berkeley Lake, GA (US);
Scientific-Atlanta, Inc., Lawrenceville, GA (US);
Abstract
The present invention provides several embodiments of a video carrier signal detection circuit included in an optical transmitter for either disabling an oscillator that provides dithering tones or attenuating the power level of the dither tones. A first detection circuit detects the presence of a video carrier signal by analyzing a known video channel. The power level of a video sync pulse included in the known video channel is then compared to a reference power level. A second detection circuit compares the composite power level of the RF signals in a predetenmined frequency spectrum with a reference power level to determine either the presence of a video carrier signal or an increase in the channel loading. Upon detection of a video carrier signal or an increase in composite power, an enable signal is provided to either the oscillator or an attenuating device depending upon the detection circuit.