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:
Oct. 22, 1996
Filed:
Sep. 16, 1993
Applicant:
Inventors:
Bruce H Williams, Sandy, UT (US);
Glenn A Arbanas, Salt Lake City, UT (US);
Roy E Greeff, Salt Lake City, UT (US);
Assignee:
Unisys Corporation, Blue Bell, PA (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03D / ;
U.S. Cl.
CPC ...
375344 ; 375327 ; 375373 ; 375376 ;
Abstract
An improved phase locked indication circuit for a Costas QPSK carrier recovery loop comprises an inphase channel, a quadrature channel and phase error channel each connected to an input of a three input summing circuit through a diode square law multiplier and wherein the error channel signal is filtered by a low pass filter to smooth the signal before being applied to the negative input of the summing circuit to diminish false lock and not locked signals. The locked and not lock conditions are separated one from the other by a large signal to noise ratio.