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, 1993
Filed:
Jan. 24, 1991
Roger K Loper, Marion, IA (US);
Rockwell International Corporation, , CA (US);
Abstract
A system for detecting and controlling gain and phase errors in a direct conversion receiver having a pair of signal channels carrying I and Q baseband signal components which are in quadrature and are a function of a phase angle .theta.. The system operates by generating I' and Q' signals which correspond to sin(2.theta.) and cos(2.theta.). These I' and Q' signals are then normalized with respect to signal amplitude and filtered to produce signals DC.sub.I and DC.sub.Q corresponding to their DC components. The resulting signals DC.sub.I and DC.sub.Q have been discovered to be separately correlated with the gain and phase errors, respectively, and are used in adjusting the original I and Q baseband signal components to correct for any such errors existing between them.