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:
Jul. 20, 2004
Filed:
Dec. 23, 2002
Phase locked loop demodulator and demodulation method using feed-forward tracking error compensation
Richard K. Karlquist, Cupertino, CA (US);
Agilent Technologies, Inc., Palo Alto, CA (US);
Abstract
In embodiment, the present invention is directed to a PLL phase demodulator that utilizes feed-forward error correction. The feed-forward error correction may occur by calibrating an equalizer to possess transfer function that emulates the modulation response curve of the VCO of the PLL phase demodulator. In operation, the equalizer may receive the filtered and integrated version of the error signal produced by the phase detector of the PLL. The equalizer filters the received signal according to the calibrated transfer function. The output of the equalized is provided to a adder to combine the equalized signal with the error signal produced by the phase detector. A similar arrangement including a suitably calibrated equalizer may be utilized to address phase tracking error in a PLL frequency demodulator.