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. 30, 2006
Filed:
Mar. 21, 2001
Hideyuki Nosaka, Musashino, JP;
Hiroyuki Fukuyama, Musashino, JP;
Hideki Kamitsuna, Musashino, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
NTT Electronics Corporation, Tokyo, JP;
Abstract
A phase lock circuit has a signal path to which a phase comparator, a loop filter and a voltage control oscillator are connected in series, the phase comparator being adapted to compare the phase of an input signal Vwith the phase in the output signal of the voltage control oscillator and to output its result of comparison, the loop filter being adapted to receive the output signal of the phase comparator and to output a DC voltage; the voltage control oscillator being adapted to control the output oscillation frequency depending on the DC output voltage of the loop filter, the phase lock circuit further comprising voltage tracking means for adding, to the voltage of the signal path, a signal causing the average voltage in the output voltage of the phase comparator to coincide with a predetermined reference voltage, whereby the voltage tracking means can enlarge the lock range in the phase lock circuit.