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:
Apr. 18, 1978
Filed:
Nov. 26, 1976
Applicant:
Inventors:
Carl R Ryan, Hancock, MN (US);
James H Stilwell, Scottsdale, AZ (US);
Assignee:
Motorola, Inc., Schaumburg, IL (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03D / ;
U.S. Cl.
CPC ...
329124 ; 325472 ; 329133 ; 331 12 ;
Abstract
An improved quadraphase shift keyed (QPSK) adaptive demodulator includes a Costas loop modified to independently cross couple the inphase (I) and quadraphase (.phi.) channels so that minimum cross talk takes place between the I and Q channels. Advantageously, the improved QPSK adaptive demodulator separates the feedback control for correcting the phasor errors in the I and Q phasors. Advantageously, the improved demodulator permits independent phase adjustment of the I and Q demodulator outputs.