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:
May. 23, 1989
Filed:
Mar. 30, 1988
Applicant:
Inventor:
Stanley W Attwood, Sun Lakes, AZ (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04L / ;
U.S. Cl.
CPC ...
329 50 ; 329124 ; 375 83 ; 375 87 ;
Abstract
A quadraphase shift keyed (QPSK) demodulator employs a pseudo data estimation loop for reducing the loop gain variation. This demodulator has a feedback loop to minimize the cross-coupling between the i anf q channels. This demodulator also provides as outputs the signals representing the amplitude of i and q channels. In addition, by eliminating amplification of some of the internally generated signals, this demodulator may serve as a biphase shift keyed (BPSK) demodulator.