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:
Dec. 28, 1999
Filed:
Jan. 17, 1997
Stephen R Wynn, Lynchburg, VA (US);
Ericsson Inc., Research Triangle Park, NC (US);
Abstract
In a complex signal receiver, quadrature imbalances in phase angle and amplitude are detected and compensated. A known signal is applied to a quadrature receiver and converted into inphase and quadrature baseband signals. A signal processor determines an imbalance between the inphase and quadrature signals of the known signal and generates one or more correction factors in response to the determined imbalance. The correction factors are applied to subsequently received inphase and quadrature baseband signals to minimize the imbalance between the subsequently received inphase and quadrature baseband signals. The imbalance compensation and correction technique is also useful to quadrature transmitters that employ feedback control. The quadrature imbalance detection and correction circuitry may be integrated on the same integrated circuit chip as the receiver circuitry to provide a single, universal receiver chip.