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, 1989
Filed:
May. 09, 1988
Gregory M Cutler, Cupertino, CA (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
Circuit imperfections in phase modulators will introduce offsets in the servo error signals in frequency locking circuits. Such offsets will also cause a frequency offset. The frequency offset is first reduced by reducing or removing amplitude modulation at the modulating frequency in the modulated carrier signal. In the preferred embodiment, this is accomplished by a coupled servo which includes a matrix loop filter. After the amplitude modulation at the modulating frequency has been removed, sideband imbalance can be corrected by amplitude modulating the modulating signal so that the offset caused by sideband imbalance is reduced or eliminated. This will be the case provided that the integral of at least the third power of the amplitude modulation vanishes.