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:
Jan. 14, 1997
Filed:
Nov. 30, 1995
Hiroyuki Kiyanagi, Sendai, JP;
Takanori Iwamatsu, Kawasaki, JP;
Fujitsu Limited, Kanagawa, JP;
Abstract
A carrier regeneration circuit achieves quick frequency synchronization without using a sweeper. An area judging device judges whether a baseband signal, quadrature-demodulated with a regenerated carrier output from a voltage-controlled oscillator, lies inside a designated area in a phase plane. If it is inside the designated area, an output of a phase comparator is selected, and if it has exited the area, the previous value is held. The designated area is set so that the direction of control indicated by the phase comparator, just before the baseband signal rotating in the phase plane exits the area, coincides with a direction that suppresses the rotation.