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:
Jun. 12, 2001
Filed:
May. 11, 1999
Naoki Okamoto, Osaka, JP;
Norihide Kinugasa, Kyoto, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A compact, inexpensive circuit for generating several stable reference signals from several burst signals is provided. The circuit comprises a first oscillator using a quartz oscillator; a second oscillator with a variable oscillation frequency having a range broader than that of the first voltage-controlled oscillator; a first frequency divider for dividing a frequency of an output signal of the first oscillator by j; a second frequency divider for dividing a frequency of an output signal of the second oscillator by k; a first phase comparator for comparing a phase of an output signal of the first frequency divider with a phase of an output signal of the second frequency divider; a first lowpass filter for smoothing an output signal of the first phase comparator and returning the smoothed signal as feedback to a control terminal of the second oscillator; a second phase comparator for comparing a phase of an output signal of the second oscillator with a phase of the burst signal; and a second lowpass filter for smoothing an output signal of the second phase comparator and returning the smoothed signal as feedback to a control terminal of the first oscillator. The continuous reference signal with the desired frequency is obtained from the output signal of the second oscillator.