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:
Jan. 02, 2001
Filed:
Feb. 23, 1999
Thomas Hafemeister, Hamburg, DE;
U.S. Philips Corporation, New York, NY (US);
Abstract
In a circuit arrangement for demodulating an intermediate-frequency video signal generated while using a Nyquist edge, having a phase-locked loop (,) including a phase detector (,), a loop filter (,) and a voltage-controlled oscillator (,), and a video demodulator (,), the intermediate-frequency video signal being applied to the phase detector (,) and the output signal of the phase-locked loop (,) being applied to the video demodulator (,), which converts the intermediate-frequency video signal into a baseband video signal, phase fluctuations contained in the carrier of the intermediate-frequency video signal due to its generation while using a Nyquist edge are compensated in that the phase comparator (,) operates, by approximation, independently of modulation in the control range of the intermediate-frequency video signal, in that the baseband video signal is present in an inverted form with respect to the intermediate-frequency video signal, and in that a correction signal is derived from the baseband video signal by at least a feedback capacitor (,), this correction signal having signal components of opposite amplitude and phase position to those contained in the intermediate-frequency video signal and caused by the Nyquist edge, and is applied to the loop filter (,).